:  Oct 20, 2004



4.4 Liter Electronic Engine Controls-Component Location (Sheet 1of 2)



1  - Crankcase ventilation valve (PCV)
2  - Fuel rail temperature sensor
3  - Injectors
4  - Knock sensor
5  - Camshaft position sensor (CMP)
6  - Manifold Absolute Pressure sensor (MAP)
7  - Universal Heated Exhaust Gas Oxygen (UHEGO) sensors
8  - Heated Exhaust Gas Oxygen (HEGO) sensors
9  - Crankshaft position sensor
10  - Spark plugs
11  - Ignition coils
12  - Variable Valve Timing (VVT) oil control solenoid
13  - Mas Air Flow (MAF) sensor
14  - Exhaust Gas Recirculation (EGR) valve
15  - Electric throttle

4.4 Liter Electronic Engine Controls-Component Location (Sheet 2 of 2)



1  - Main relay
2  - Transfer box control module
3  - Engine Control Module (ECM)
4  - Accelerator Pedal Position sensor (APP)
5  - Brake light switch
6  - Antilock Braking System (ABS) control module

4.4 Liter Electronic Engine Controls-Input Control Diagram (Sheet 1 of 2)



1  - Main relay
2  - Camshaft sensor (CMP)
3  - Crankshaft position sensor (CKP)
4  - Engine Coolant Temperature sensor (ECT
5  - Accelerator Pedal Position sensor (APP)
6  - Manifold Absolute Pressure Sensor (APP)
7  - Engine oil temperature sensor
8  - Mass Air Flow/Inlet Air Temperature sensor (MAF/IAT)
9  - Fuel rail temperature sensor
10  - Restraints control module
11  - Brake light switch
12  - Clutch switch (Not used)
13  - Knock sensors
14  - ECM
15   Fuse 60 P
16  - Fuse 25 P
17  - Ignition switch
18  - Fuseable link 11 E

4.4 Liter Electronic Engine Controls-Control Diagram (Sheet 2 of 2)

:
  A= Hardwired D= CAN



1  - Injectors
2  - Engine cooling fan
3  - Variable Valve Timing (VVT) oil control solenoids
4  - ABS control module
5  - Instrument pack
6  - EAT control module
7  - Restraints control module
8  - Differential control module
9  - Transfer box control module
10  - Electric park brake control module
11  - ATC control module
12  - UHEGO
13  - Ignition coils
14  - HEGO
15  - Generator
16  - ECM
17  - EGR valve
18  - Clock spring
19  - Speed control switches
20  - Electric throttle

GENERAL

The V8 4.4 Liter engine is controlled by a Engine Control Module (ECM) manufactured by DENSO. The Engine Management System (EMS) controls the following:

The ECM controls the engine fuelling by providing sequential fuel injection to all cylinders. Ignition is controlled by a direct ignition system, provided by eight plug top coils. The ECM is able to detect and correct for ignition knock on each cylinder and adjust the ignition timing for each cylinder to achieve optimum performance.

The ECM uses a torque-based strategy to generate the torque required by the driver and other vehicle ECU's. The EMS uses various sensors to determine the torque required from the engine. The EMS also interfaces with other vehicle electronic control modules's, via the CAN bus, to obtain additional information (e.g. road speed from the ABS control module). The EMS processes these signals and decides how much torque to generate. Torque is then generated by using various actuators to supply air, fuel and spark to the engine (electronic throttle, injectors, coils, etc.).

ENGINE CONTROL MODULE (ECM)



The ECM is located in the E-Box in the plenum area on the LH side of the engine compartment attached to the bulkhead.

System ECM has the following inputs:

The ECM outputs to the following:

ECM Connector C0634 Pin Out Table

Pin No Description Input/Output
1 CAN Input/Output
2 CAN Input/Output
3 Generator monitor Input
4 UHEGO Bank A ground -
5 UHEGO Bank B ground -
6 Not used -
7 Not used -
8 Not used -
9 Not used -
10 Not used -
11 CKP ground -
12 CMP sensor bank A ground -
13 CMP sensor bank B ground -
14 UHEGO sensor bank B signal Input
15 Electronic throttle body ground -
16 MAF ground -
17 HEGO ground -
18 Not used -
19 Knock sensor 1 ground -
20 Knock sensor 2 ground -
21 Knock sensor 3 ground -
22 Knock sensor 4 ground -
23 Electronic throttle body 5V supply Output
24 Fuel pump relay Output
25 Not used -
26 Not used -
27 Not used -
28 Not used -
29 Radiator temperature sensor Input
30 Crank sensor signal Input
31 Not used -
32 Not used -
33 CMP signal bank B Input
34 CMP signal bank A Input
35 Not used -
36 UHEGO signal bank A Input
37 UHEGO signal bank A ground -
38 UHEGO signal bank B ground -
39 Fuel temperature sensor Input
40 Fuel pressure sensor Input
41 Not used Input
42 Not used Input
43 Knock sensor 1 + Output
44 Knock sensor 2 + Output
45 Knock sensor 3 + Output
46 Knock sensor 4 + Output
47 Generator control Output
48 E-box fan Output
49 Not used -
50 EGR stepper motor 4 Output
51 EGR stepper motor 3 Output
52 EGR stepper motor 2 Output
53 EGR stepper motor 1 Output
54 Ignition coil cylinder 4 B Output
55 Ignition coil cylinder 4 A Output
56 Ignition coil cylinder 3 B Output
57 Not used -
58 Not used -
59 Not used -
60 Not used -
61 Not used -
62 Not used -
63 Not used -
64 Not used -
65 Not used -
66 Not used -
67 Not used -
68 Not used -
69 Not used -
70 MAF Input
71 Purge valve Output
72 Starter relay - -
73 Throttle body power supply Output
74 Throttle valve open direction - Output
75 Throttle valve open direction + Output
76 UHEGO Heater bank A Output
77 UHEGO Heater bank B Output
78 Injector cylinder 4B Output
79 Injector cylinder 4A Output
80 Injector cylinder 3B Output
81 Injector cylinder 3A Output
82 Injector cylinder 2B Output
83 Injector cylinder 2A Output
84 Injector cylinder 1B Output
85 Injector cylinder 1A Output
86 VVT bank A Output
87 VVT bank B Output
88 Viscous fan control Output
89 Not used -
90 Oil temperature sensor Input
91 Throttle body monitor signal Input
92 Starter motor relay + Output
93 Not used -
94 Viscous fan request Input
95 Purge valve Output

ECM Connector C0635 Pin Out Table

Pin No Description Input/Output
1 Signal ground 1 -
2 Power ground 1 -
3 Power ground 3 -
4 Power ground 2 -
5 ECM power Input
6 APP sensor ground 1 -
7 APP sensor ground 2 -
8 Not used -
9 Not used -
10 Not used -
11 Not used -
12 Park/ Neutral signal Input
13 Not used -
14 Not used -
15 Not used -
16 EMS relay Output
17 Crank request Output
18 CAN + Output
19 APP sensor 2 power Output
20 Fuel pump control Output
21 Not used -
22 Not used -
23 Not used -
24 APP sensor 1 signal Output
25 Not used -
26 Brake light switch Input
27 Not used -
28 Not used -
29 Not used -
30 Ignition switch Input
31 CAN + Input
32 APP sensor 1 power Output
33 DMTL Output
34 Not used -
35 Cruise switch - Output
36 Cruise switch + Input

CRANKSHAFT POSITION SENSOR (CKP)



The crankshaft position sensor is mounted at the rear underside of the engine near the transmission bell housing. Connection between the sensor and the harness is via a link harness and a two-way connector. Both wires go directly to the ECM. The sensor produces the signal which enables the ECM to determine the angle of the crankshaft, and the engine rpm. From this, the point of ignition, fuel injection, etc. is calculated. If the signal wires are reversed a 3° advance in timing will occur, as the electronics within the ECM uses the falling edge of the signal waveform as its reference / timing point for each tooth.

The reluctor is pressed into the flywheel and has a "tooth" pattern based on 36 teeth at 10° intervals and approximately 3° wide: one of the teeth is removed to provide a hardware reference mark which is 60 degrees BTDC No.1 cylinder. Because of the crankshaft sensor's orientation, the target wheel uses windows machined into the face, rather than actual teeth.

The sensor operates by generating an output voltage caused by the change in magnetic field that occurs as the windows pass in front of the sensor. The output voltage varies with the speed of the windows passing the sensor, the higher the engine speed, the higher the output voltage. Note that the output is also dependent on the air gap between the sensor and the teeth (the larger the gap, the weaker the signal, the lower the output voltage). The ECM transmits the engine speed to other vehicle ECU's on CAN.

CAMSHAFT POSITION SENSOR (CMP)



Two sensors are located at the rear of the engine, in the cylinder head (one per bank), above the rear cylinders. This is a Variable Reluctor Sensor (VRS) producing four pulses for every two engine revolutions. The sensing element is positioned between 0 and 2mm from the side of the cam gear wheel.

The variable cam inlet is parked in the retarded position and can advance up to 48 degrees.

The camshaft timing wheel is a sintered component which has four teeth on it to enable the EMS to detect cylinder identification. The signal is used for:

Failure symptoms include:

ENGINE COOLANT TEMPERATURE SENSOR (ECT)



The sensor is located at the front of the engine in the water pipe below the throttle body. The ECT sensor is a thermistor used to monitor the engine coolant temperature. The engine coolant temperature sensor is vital to the correct running of the engine as a richer mixture is required at lower block temperatures for good quality starts and smooth running, leaning off as the temperature rises to maintain emissions and performance.

The sensor has an operating temperature range of -30 Degrees Celsius to 125 Degrees Celsius. When a defective coolant sensor is detected, the ECM uses the oil temperature sensor value.

ENGINE OIL TEMPERATURE SENSOR



Oil temperature is monitored through a temperature sensor mounted in the oil system. This component is a NTC (negative temperature coefficient) . The sensor is mounted next to the oil pressure sensor at the front of the engine and locates into the oil filter bracket.

FUEL RAIL TEMPERATURE SENSOR



The fuel rail temperature sensor measures the temperature of the fuel in the fuel rail. This input is then used to deliver the correct quantity of fuel to the engine. Operating Range -40 Degrees Celsius to 150 Degrees Celsius. The fuel rail temperature sensor is fitted on the rear of the right hand bank (bank A) fuel rail.

MASS AIR FLOW/INLET AIR TEMPERATURE SENSOR (MAF/IAT)



The air flow meter is located in the clean air duct immediately after the air filter box.

The air mass flow is determined by the cooling effect of inlet air passing over a “hot film” element contained within the device. The higher the air flow the greater the cooling effect and the lower the electrical resistance of the “hot film” element. The ECM then uses this signal from the Mass Air Flow meter to calculate the air mass flowing into the engine.

The measured air mass flow is used in determining the fuel quantity to be injected in order to maintain the stichometric air/fuel mixture required for correct operation of the engine and exhaust catalysts. Should the device fail there is a software backup strategy that will be evoked once a fault has been diagnosed.

The following symptoms may be observed if the sensor fails:

The Inlet Air Temperature (IAT) sensor is integrated into the Mass Air Flow meter. It is a temperature dependent resistor (thermistor), i.e. the resistance of the sensor varies with temperature. This thermistor is a negative temperature coefficient (NTC) type element meaning that the sensor resistance decreases as the sensor temperature increases. The sensor forms part of a voltage divider chain with an additional resistor in the ECM. The voltage from this sensor changes as the sensor resistance changes, thus relating the air temperature to the voltage measured by the ECM.

The ECM stores a 25°C default value for air temperature in the event of a sensor failure.

MANIFOLD ABSOLUTE PRESSURE SENSOR (MAP)



The MAP sensor provides a voltage proportional to the absolute pressure in the intake manifold. This signal allows the load on the engine to be calculated and used within the internal calculations of the ECM. The sensor is located on the rear of the air intake manifold.

Pin No Description
1 MAP signal
2 Sensor supply
3 Not used
4 Sensor ground

The output signal from the MAP sensor, together with the CKP and IAT sensors, is used by the ECM to calculate the amount of air induced into the cylinders. This enables the ECM to determine ignition timing and fuel injection duration values.

The MAP sensor receives a 5V supply voltage from pin 48 of ECM connector C0634 and provides an analogue signal to pin 69 of ECM connector C0634, which relates to the absolute manifold pressure and allows the ECM to calculate engine load. The ECM provides a ground for the sensor via pin 11 of ECM connector C0634.

If the MAP signal is missing, the ECM will substitute a default manifold pressure reading based on crankshaft speed and throttle angle. The engine will continue to run with reduced drivability and increased emissions, although this may not be immediately apparent to the driver. The ECM will store fault codes which can be retrieved using T4.

KNOCK SENSORS



The V8 EMS has two knock sensors located in the V of the engine, one per cylinder bank. The sensors are connected to the ECM via a twisted pair.

The knock sensors produce a voltage signal in proportion to the amount of mechanical vibration generated at each ignition point. Each sensor monitors the related cylinder bank.

The knock sensors incorporate a piezo-ceramic crystal. This crystal produces a voltage whenever an outside force tries to deflect it, (i.e. exerts a mechanical load on it). When the engine is running, the compression waves in the material of the cylinder block, caused by the combustion of the fuel/air mixture within the cylinders, deflect the crystal and produce an output voltage signal. The signals are supplied to the ECM, which compares them with `mapped' signals stored in memory. From this, the ECM can determine when detonation occurs on individual cylinders. When detonation is detected, the ECM retards the ignition timing on that cylinder for a number of engine cycles, then gradually returns it to the original setting.

Care must be taken at all times to avoid damaging the knock sensors, but particularly during removal and fitting procedures. The recommendations regarding torque and surface preparation must be adhered to. The torque applied to the sensor and the quality of the surface preparation both have an influence over the transfer of mechanical noise from the cylinder block to the crystal.

The ECM uses the signals supplied by the knock sensors, in conjunction with the signal it receives from the camshaft sensor, to determine the optimum ignition point for each cylinder. The ignition point is set according to preprogrammed ignition maps stored within the ECM. The ECM is programmed to use ignition maps for 98 RON premium specification fuel. It will also function on 91 RON regular specification fuel and learn new adaptions. If the only fuel available is of poor quality, or the customer switches to a lower grade of fuel after using a high grade for a period of time, the engine may suffer slight pre-ignition for a short period. This amount of pre-ignition will not damage the engine. This situation will be evident while the ECM learns and then modifies its internal mapping to compensate for the variation in fuel quality. This feature is called adaption. The ECM has the capability of adapting its fuel and ignition control outputs in response to several sensor inputs.

The ECM will cancel closed loop control of the ignition system if the signal received from either knock sensor becomes implausible. In these circumstances the ECM will default to a safe ignition map. This measure ensures the engine will not become damaged if low quality fuel is used. The MIL lamp will not illuminate, although the driver may notice that the engine 'pinks' in some driving conditions and displays a drop in performance and smoothness.

When a knock sensor fault is stored, the ECM will also store details of the engine speed, engine load and the coolant temperature.

ELECTRONIC THROTTLE



The V8 EMS incorporates an electric throttle control system. The electronic throttle body is located on the air intake manifold in the engine compartment. The system comprises three main components:

When the accelerator pedal is depressed the APP sensor provides a change in the monitored signals. The ECM compares this against an electronic “map” and moves the electronic throttle valve via a pulse width modulated (PWM) control signal which is in proportion to the APP angle signal. The system is required to:

A software strategy within the ECM enables the throttle position to be calibrated each ignition cycle. When the ignition is turned ON, the ECM performs a self test and calibration routine on the electronic throttle by opening and closing the throttle fully.

Electronic Throttle Pin Out Table

Pin No Description
1 Motor -
2 Motor +
3 Sensor ground
4 Sensor 2 signal
5 Sensor 1 signal
6 5 volt supply

ACCELERATOR PEDAL POSITION SENSOR (APP)



The APP sensors are located on the accelerator pedal assembly.

The APP sensors are used to determine the driver's request for vehicle speed, acceleration and deceleration. This value is used by the ECM and the throttle is opened to the correct angle by an electric motor integrated into the throttle body.

The APP Sensor signals are checked for range and plausibility. Two separate reference voltages are supplied to the pedal. Should one sensor fail, the other is used as a 'limp – home' input. In limp home mode due to an APP signal failure the ECM will limit the maximum engine speed to 2000 rpm.

Accelerator Pedal Position Sensor (APP) Pin Out Table

Pin No Description
1 APP2 ground
2 APP 1 demand
3 APP 1 ground
4 Not used
5 APP 2 demand
6 Supply 2, 5 volt
7 Supply 1, 5 volt
8 Not used

OXYGEN SENSORS

There are four oxygen sensors located in the exhaust system. Two upstream before the catalytic converter and two down stream after the catalytic converter. The sensor monitors the level of oxygen in the exhaust gases and is used to control the fuel/air mixture. Positioning a sensor in the stream of exhaust gasses from each bank enables the ECM to control the fuelling on each bank independently of the other, allowing much closer control of the air / fuel ratio and catalyst conversion efficiency.

Upstream Oxygen Sensors



Downstream Oxygen Sensors



The oxygen sensors need to operate at high temperatures in order to function correctly. To achieve the high temperatures required, the sensors are fitted with heater elements that are controlled by a PWM signal from the ECM. The heater elements are operated immediately following engine start and also during low load conditions when the temperature of the exhaust gases is insufficient to maintain the required sensor temperatures. A non-functioning heater delays the sensor’s readiness for closed loop control and influences emissions. The PWM duty cycle is carefully controlled to prevent thermal shock to cold sensors.

UHEGO (Universal Heated Exhaust Gas Oxygen) sensors also known as Linear or "Wide Band" sensors produces a constant voltage, with a variable current that is proportional to the oxygen content. This allows closed loop fuelling control to a target lambda, i.e. during engine warm up (after the sensor has reached operating temperature and is ready for operation). This improves emission control.

The HEGO sensor uses Zirconium technology that produces an output voltage dependant upon the ratio of exhaust gas oxygen to the ambient oxygen. The device contains a Galvanic cell surrounded by a gas permeable ceramic, the voltage of which depends upon the level of O2 defusing through. Nominal output voltage of the device for l =1 is 300 to 500m volts. As the fuel mixture becomes richer (l<1) the voltage tends towards 900m volts and as it becomes leaner (l>1) the voltage tends towards 0 volts. Maximum tip temperature is 1,000 Degrees Celsius for a maximum of 100 hours.

Sensors age with mileage, increasing their response time to switch from rich to lean and lean to rich. This increase in response time influences the ECM closed loop control and leads to progressively increased emissions. Measuring the period of rich to lean and lean to rich switching monitors the response rate of the upstream sensors.

Diagnosis of electrical faults is continually monitored in both the upstream and downstream sensors. This is achieved by checking the signal against maximum and minimum threshold, for open and short circuit conditions.

Oxygen sensors must be treated with the utmost care before and during the fitting process. The sensors have ceramic material within them that can easily crack if dropped / banged or over-torqued. The sensors must be torqued to the required figure, (40-50Nm), with a calibrated torque wrench. Care should be taken not to contaminate the sensor tip when anti-seize compound is used on the thread. Heated sensor signal pins are tinned and universal are gold plated. Mixing up sensors could contaminate the connectors and affect system performance.

Failure Modes Failure Symptoms It is possible to fit front and rear sensors in their opposite location. However the harness connections are of different gender and colour to ensure that the sensors cannot be incorrectly connected. In addition to this the upstream sensors have two holes in the shroud, whereas the down stream sensors have four holes in the shroud for the gas to pass through.

GENERATOR



The Generator has a multifunction voltage regulator for use in a 14V charging system with 6÷12 zener diode bridge rectifiers.

The ECM monitors the load on the electrical system via PWM signal and adjusts the generator output to match the required load. The ECM also monitors the battery temperature to determine the generator regulator set point. This characteristic is necessary to protect the battery; at low temperatures battery charge acceptance is very poor so the voltage needs to be high to maximise any rechargeability, but at high temperatures the charge voltage must be restricted to prevent excessive gassing of the battery with consequent water loss.

The Generator has a smart charge capability that will reduce the electrical load on the Generator reducing torque requirements, this is implemented to utilise the engine torque for other purposes. This is achieved by monitoring three signals to the ECM:

FUEL INJECTORS



The engine has 8 fuel injectors (one per cylinder), each injector is directly driven by the ECM. The injectors are fed by a common fuel rail as part of a ‘returnless’ fuel system. The fuel rail pressure is regulated to 4.5 bar by a fuel pressure regulator which is integral to the fuel pump module, within the fuel tank. The injectors can be checked by resistance checks. There is a fuel pressure test Schrader valve attached to the fuel rail on the front LH side for fuel pressure testing purposes. The ECM monitors the output power stages of the injector drivers for electrical faults.

The injectors have a resistance of 13.8 Ohms ± 0.7 Ohms @ 20 Degrees Celsius   Fuel Charging and Controls (303-04B Fuel Charging and Controls - 4.4L)


IGNITION COILS



The V8 engine is fitted with eight plug-top coils that are driven directly by the ECM. This means that the ECM, at the point where sufficient charge has built up, switches the primary circuit of each coil and a spark is produced in the spark plug. The positive supply to the coil is fed from a common fuse. Each coil contains a power stage to trigger the primary current. The ECM sends a signal to each of the coils power stage to trigger the power stage switching. Each bank has a feedback signal that is connected to each power stage. If the coil power stage has a failure the feedback signal is not sent, causing the ECM to store a fault code appropriate to the failure.

The ECM calculates the dwell time depending on battery voltage and engine speed to ensure constant secondary energy. This ensures sufficient secondary (spark) energy is always available, without excessive primary current flow thus avoiding overheating or damage to the coils.

The individual cylinder spark timing is calculated from a variety of inputs:

  Engine Ignition (303-07B Engine Ignition - 4.4L)


FUEL PUMP RELAY

The V8 engine has a returnless fuel system. The system pressure is maintained at a constant 4 bar (59 Psi), with no reference to intake manifold pressure. The fuel is supplied to the injectors from a fuel pump fitted within the fuel tank. The electrical supply to this fuel pump is controlled by the ECM via a relay and an Inertia Switch which will turn the fuel off upon a vehicle impact. The fuel system is pressurised as soon as the ECM is powered up, the pump is then switched off until engine start has been achieved.

VISCOUS FAN CONTROL

The ECM controls a viscous coupled fan to provide engine cooling. The ECM supplies the fan with a PWM signal that controls the amount of slippage of the fan, thus providing the correct amount of cooling fan speed and airflow. The EMS uses a Hall Effect sensor to determine the fan speed.   Engine Cooling (303-03B Engine Cooling - 4.4L)


VARIABLE VALVE TIMING (VVT)

Variable valve timing is used on the V8 engine to enhance low and high speed engine performance and idle speed quality.

For each inlet camshaft the VVT system comprises:

The VVT system alters the phase of the intake valves relative to the fixed timing of the exhaust valves, to alter:

The VVT unit uses a vane type device to control the camshaft angle. The system operates over a range of 48 degrees and is advanced or retarded to its optimum position within this range.

The VVT system is controlled by the ECM based on engine load and speed along with engine oil temperature to calculate the appropriate camshaft position.

The VVT system provides the following advantages:

Variable Valve Timing Unit



The VVT unit is a hydraulic actuator mounted on the end of the inlet camshaft. The unit advances or retards the camshaft timing to alter the camshaft to crankshaft phase. The ECM controls the VVT timing unit via a oil control solenoid. The oil control solenoid routes oil pressure to the advance or retard chambers either side of the vanes within the VVT unit.

The VVT unit is driven by the primary drive chain and rotates relative to the exhaust camshaft. When the ECM requests a retard in camshaft timing the oil control solenoid is energised which moves the shuttle valve in the solenoid to the relevant position allowing oil pressure to flow out of the advance chambers in the VVT unit whilst simultaneously allowing oil pressure into the retard chambers.

The ECM controls the advancing and retarding of the VVT unit based on engine load and speed. The ECM sends an energise signal to the oil control solenoid until the desired VVT position is achieved. When the desired VVT position is reached, the energising signal is reduced to hold the oil control solenoid position and consequently desired VVT position. This function is under closed loop control and the ECM can sense any variance in shuttle valve oil pressure via the camshaft position sensor and can adjust the energising signal to maintain the shuttle valve hold position.

VVT operation can be affected by engine oil temperature and properties. At very low oil temperatures the movement of the VVT mechanism will be slow due to the high viscosity of the oil. While at high oil temperatures the low oil viscosity may impair the VVT operation at low oil pressures. The oil pump has the capacity to cope with these variations in oil pressure while an oil temperature sensor is monitored by the ECM to provide oil temperature feedback. At extremely high oil temperatures the ECM may limit the amount of VVT advance in order to prevent the engine from stalling when returning to idle speed.

VVT does not operate when engine oil pressure is below 1.25 bar. This is because there is insufficient pressure to release the VVT units internal stopper pin. This occurs when the engine is shut down and the VVT unit has returned to the retarded position. The stopper pin locks the VVT unit to the camshaft to ensure camshaft stability during the next start up.   Engine (303-01B Engine - 4.4L)


Valve Timing Solenoid



Valve Timing Solenoid

The valve timing solenoid controls the position of the shuttle valve in the bush carrier. A plunger on the solenoid extends when the solenoid is energised and retracts when the solenoid is de-energised.

When the valve timing solenoids are de-energised, the coil springs in the bush carriers position the shuttle valves to connect the valve timing units to drain. In the valve timing units, the return springs hold the ring pistons and gears in the retarded position. When the valve timing solenoids are energised by the ECM, the solenoid plungers position the shuttle valves to direct engine oil to the valve timing units. In the valve timing units, the oil pressure overcomes the force of the return springs and moves the gears and ring pistons to the advanced position. System response times are 1.0 second maximum for advancing and 0.7 second maximum for retarding. While the valve timing is in the retarded mode, the ECM produces a periodic lubrication pulse. This momentarily energises the valve timing solenoids to allow a spurt of oil into the valve timing units. The lubrication pulse occurs once every 5 minutes.

EXHAUST GAS RECIRCULATION (EGR) VALVE



The Exhaust Gas Recirculation (EGR) valve is an electrically controlled valve that allows burned exhaust gas to be recirculated back into the engine. The EGR valve consists of a stepper motor that opens and closes the valve in steps. Since exhaust gas has much less oxygen than air, it is basically inert. It takes the place of air in the cylinder and reduces combustion temperature. As the combustion temperature is reduced, so are the oxides of nitrogen (NOx).

The EGR valve is located on the intake manifold with a pipe connecting the exhaust manifold to the valve. Connection between the sensor and the harness is via a six-way connector.   Engine Emission Control (303-08B Engine Emission Control - 4.4L)


ECM ADAPTIONS

The ECM has the ability to adapt the values it uses to control certain outputs. This capability ensures the EMS can meet emissions legislation and improve the refinement of the engine throughout its operating range.

The components which have adaptions associated with them are:



UHEGO/HEGO and MAF/IAT Sensor

There are several adaptive maps associated with the fuelling strategy. Within the fuelling strategy the ECM calculates short-term adaptions and long term adaptions. The ECM will monitor the deterioration of the oxygen sensors (HEGO and UHEGO) over a period of time. It will also monitor the current correction associated with the sensors.

The ECM will store a fault code in circumstances where an adaption is forced to exceed its operating parameters. At the same time, the ECM will record the engine speed, engine load and intake air temperature.

CKP Sensor

The characteristics of the signal supplied by the CKP sensor are learned by the ECM. This enables the ECM to set an adaption and support the engine misfire detection function. Due to the small variation between different flywheels and different CKP sensors, the adaption must be reset if either component is renewed, or removed and refitted. It is also necessary to reset the flywheel adaption if the ECM is renewed or replaced. The ECM supports four flywheel adaptions for the CKP sensor. Each adaption relates to a specific engine speed range. The engine speed ranges are detailed in the table below:

Adaptions Engine Speed, rev/min
1 1800 - 3000
2 3001 - 3800
3 3801 - 4600
4 4601 - 5400

Misfire Detection

Legislation requires that the ECM must be able to detect the presence of an engine misfire. It must be able to detect misfires at two separate levels. The first level is a misfire that could lead to the vehicle emissions exceeding 1.5 times the Federal Test Procedure (FTP) requirements for the engine. The second level is a misfire that may cause catalyst damage.

The ECM monitors the number of misfire occurrences within two engine speed ranges. If the ECM detects more than a predetermined number of misfire occurrences within either of these two ranges, over two consecutive journeys, the ECM will record a fault code and details of the engine speed, engine load and engine coolant temperature. In addition, the ECM monitors the number of misfire occurrences that happen in a 'window' of 200 engine revolutions. The misfire occurrences are assigned a weighting according to their likely impact on the catalysts. If the number of misfires exceeds a certain value, the ECM stores catalyst-damaging fault codes, along with the engine speed, engine load and engine coolant temperature.

The signal from the crankshaft position sensor indicates how fast the poles on the flywheel are passing the sensor tip. A sine wave is generated each time a pole passes the sensor tip. The ECM can detect variations in flywheel speed by monitoring the sine wave signal supplied by the crankshaft position sensor.

By assessing this signal, the ECM can detect the presence of an engine misfire. At this time, the ECM will assess the amount of variation in the signal received from the crankshaft position sensor and assigns a roughness value to it. This roughness value can be viewed within the real time monitoring feature, using T4. The ECM will evaluate the signal against a number of factors and will decide whether to count the occurrence or ignore it. The ECM can assign a roughness and misfire signal for each cylinder, (i.e. identify which cylinder is misfiring).

T4 Diagnostics

The ECM stores faults as Diagnostic Trouble Codes (DTC), referred to as 'P' codes. The 'P' codes are defined by OBD legislation and, together with their associated environmental and freeze frame data, can be read using a third party scan tool or T4. T4 can also read real time data from each sensor, the adaptive values currently being employed and the current fuelling, ignition and idle settings.

P Code No Component/ Signal Fault Description
P0011 CMP/CKP/VVT Bank A CMP/CKP Position error high , VVT retard position high
P0012 CMP/CKP/VVT Bank A CMP/CKP Position error low, VVT retard position low
P0021 CMP/CKP/VVT Bank B CMP/CKP Position error, VVT retard position high
P0022 CMP/CKP/VVT Bank B CMP/CKP Position error low , VVT retard position low
P0026 VVT Bank A circuit malfunction range high/ low
P0028 VVT Bank B circuit malfunction range high/ low
P0031 UHEGO Bank A heater control circuit low
P0032 UHEGO Bank A heater control circuit high
P0051 UHEGO Bank B heater control circuit low
P0052 UHEGO Bank B heater control circuit high
P0069 HAC Sensor circuit/range performance
P0071 Ambient air temperature sensor Range performance
P0072 Ambient air temperature sensor Circuit low input
P0073 Ambient air temperature sensor Circuit high input
P0075 VVT Bank A open circuit
P0076 VVT Bank A short to ground
P0077 VVT Bank A short to battery
P0081 VVT Bank B open circuit
P0082 VVT Bank B short to ground
P0083 VVT Bank B short to battery
P0087 Fuel pressure system Low fault
P0088 Fuel pressure system High fault
P0089 Fuel pressure system Noise fault
P0093 Fuel pressure system Large leak
P0096 IAT Sensor range performance
P0101 AFM Circuit range performance
P102 AFM Circuit low input
P103 AFM Circuit high input
P0106 MAP Sensor range performance
P0107 MAP Circuit low input
P0108 MAP Circuit high input
P0111 IAT Stuck high/ low at engine start, stuck high
P0112 IAT Sensor 1 circuit low input
P0113 IAT Sensor 1 circuit high input
P0116 ECT Implausible signal
P0117 ECT Circuit low input
P0118 ECT Circuit high input
P0121 Throttle circuit 1 and 2 Range/ performance
P0122 Throttle circuit 1 Low input
P0123 Throttle circuit 1 High input
P0125 ECT Insufficient coolant temperature for closed loop control
P0128 Thermostat monitor Low coolant temperature – thermostat stuck open
P0131 UHEGO Bank A short circuit to ground
P0132 UHEGO Bank A Short circuit to battery
P0133 UHEGO Bank A slow response
P0136 HEGO Bank A adaptions
P0137 HEGO Bank A short circuit to ground
P0138 HEGO Bank A short circuit to battery
P0139 HEGO Bank A slow response
P0140 HEGO Bank A no activity
P0141 HEGO Bank A heater control circuit malfunction
P0151 UHEGO Bank B short circuit to ground
P0152 UHEGO Bank B short circuit to battery
P0153 UHEGO Bank B slow response
P0156 HEGO Bank B adaptions
P0157 HEGO Bank B short circuit to ground
P0158 HEGO Bank B short circuit to battery
P0159 HEGO Bank B slow response
P0160 HEGO Bank B no activity
P0161 HEGO Bank B heater control circuit malfunction
P00171 lambda control Bank A too lean
P0172 lambda control Bank A too rich
P0174 lambda control Bank B too lean
P0175 lambda control Bank B too rich
P0181 Fuel rail temperature sensor Temperature signal implausible
P0182 Fuel rail temperature sensor Circuit low input
P0183 Fuel rail temperature sensor Circuit high input
P0191 Fuel rail pressure sensor Range /performance
P0192 Fuel Rail Pressure Sensor Low Input
P0193 Fuel Rail Pressure Sensor High Input
P0196 Oil temperature sensor Range/performance
P0197 Oil temperature sensor Low input
P0198 Oil temperature sensor High input
P0201 Injector Circuit Malfunction - Cylinder 1
P0202 Injector Circuit Malfunction - Cylinder 2
P0203 Injector Circuit Malfunction - Cylinder 3
P0204 Injector Circuit Malfunction - Cylinder 4
P0205 Injector Circuit Malfunction - Cylinder 5
P0206 Injector Circuit Malfunction - Cylinder 6
P0207 Injector Circuit Malfunction - Cylinder 7
P0208 Injector Circuit Malfunction - Cylinder 8
P0222 APP sensor 2 Low input
P0223 APP sensor 2 High input
P0227 APP sensor 1 Low input
P0228 APP sensor 1 High input
P0229 APP sensor Intermittent fault
P0297 Active speed control Vehicle over speed condition
P0300 Misfire Random/ multiple cylinder misfire
P0301 Misfire Cylinder 1
P0302 Misfire Cylinder 2
P0303 Misfire Cylinder 3
P0304 Misfire Cylinder 4
P0305 Misfire Cylinder 5
P0306 Misfire Cylinder 6
P0307 Misfire Cylinder 7
P0308 Misfire Cylinder 8
P0313 Misfire Misfire under low fuel condition
P0316 Misfire Misfire detected in first 1000 revs
P0326 Knock sensor Sensor 1 high/low performance error
P0327 Knock sensor Bank A sensor low input fault
P0328 Knock sensor Bank A high input fault
P0331 Knock sensor Sensor 2 high/low performance error
P0332 Knock sensor Bank B sensor low input fault
P0333 Knock sensor Bank A high input fault
P0335 Crank sensor Sensor circuit malfunction during crank/ running
P0336 Crank sensor Range/performance fault
P0340 Intake CMP sensor bank A Fault during cranking/running
P0341 Intake CMP sensor bank A Range/performance fault
P0345 Intake CMP sensor bank B Fault during cranking/running
P0346 Intake CMP sensor bank B Range/performance fault
P0351 Ignition coil Circuit malfunction cylinder 1
P0352 Ignition coil Circuit malfunction cylinder 2
P0353 Ignition coil Circuit malfunction cylinder 3
P0354 Ignition coil Circuit malfunction cylinder 4
P0355 Ignition coil Circuit malfunction cylinder 5
P0356 Ignition coil Circuit malfunction cylinder 6
P0357 Ignition coil Circuit malfunction cylinder 7
P0358 Ignition coil Circuit malfunction cylinder 8
P0365 Exhaust CMP sensor bank A Fault during cranking/running
P0366 Exhaust CMP sensor bank A Range/performance fault
P0390 Exhaust CMP sensor bank B Fault during cranking/running
P0391 Exhaust CMP sensor bank B Range/performance fault
P0401 EGR system Insufficient flow detected
P0403 EGR system Valve circuit high/low input
P0405 Differential pressure sensor sensor Short to ground
P0406 Differential pressure sensor sensor Short to battery
P0409 Differential pressure sensor sensor Range performance
P0420 Catalyst system bank A Efficiency below threshold
P0430 Catalyst system bank Efficiency below threshold
P0441 Purge valve Range performance
P0442 DMTL Medium leak detected
P0447 DMTL Short to ground
P0448 DMTL Short to battery
P0455 DMTL Large leak detected
P0456 DMTL Small leak detected
P0458 Purge valve Short to ground
P0459 Purge valve Short to battery
P0461 Fuel level sensor Range/performance fault
P0480 Radiator fan module Control circuit malfunction
P0493 Viscous fan Speed Out of range
P0501 Vehicle speed Range/performance malfunction
P0504 Brake switch Circuit malfunction
P0506 Idle control system RPM lower than expected
P0507 Idle control system RPM lower than expected
P0512 Crank request circuit High/low input
P0513 Security key Key invalid
P0532 Air conditioning refrigerant pressure sensor Low input
P0533 Air conditioning refrigerant pressure sensor High input
P0560 Battery back up Malfunction
P0562 Sensor power supply Low input
P0563 Sensor power supply High input
P0566 Cruise control cancel switch ON fault
P0567 Cruise control resume switch ON fault
P0568 Cruise control Low/high input
P0569 Decelerate/set/inch switch ON fault
P0570 Accelerate/set/inch switch On fault
P0574 Cruise control Speed monitoring
P0576 Cruise control Low input
P0577 Cruise control High input
P0604 ECM self test RAM error
P0605 ECM self test ROM error
P0606 ECM self test Processor error
P0616 Starter relay Low input
P0617 Starter relay High input
P0627 Primary fuel pump No commands received
P0628 Fuel pump Electrical low
P0629 Fuel pump Electrical high
P0633 Security No ID in ECM
P0634 ECM temperature Internal temperature too high
P0646 Air conditioning clutch relay Low input
P0647 Air conditioning clutch relay High input
P0661 Manifold valve output drive 1 Open circuit or short circuit to ground
P0662 Manifold valve output drive 1 Short circuit to battery
P0664 Manifold valve output drive 2 Open circuit or short circuit to ground
P0665 Manifold valve output drive 2 Short circuit to battery
P0668 ECM temperature sensor Short to ground
P0669 ECM temperature sensor Short to battery
P0687 EMS control relay Relay malfunction
P0831 Clutch switch circuit A Low input
P0832 Clutch switch circuit A High input
P0834 Clutch switch circuit B Low input
P0835 Clutch switch circuit B High input
P0851 Park / Neutral Switch Input Circuit Low
P0852 Park / Neutral Switch Input Circuit High
P1136 E Box fan Fan malfunction
P1146 Generator command line Low input/ communication error
P1155 HEGO Heater bank A Heater performance
P1160 UHEGO Bank A Slow activation
P1197 UHEGO Bank A Slow activation/open shorted
P1198 UHEGO Bank B Slow activation/open shorted
P1233 Secondary fuel pump Output circuit open
P1234 Primary fuel pump No commands received
P1236 Primary fuel pump Pump not working when requested
P1244 Alternator command line High input
P1260 Security limited start Theft attempt
P1339 Secondary fuel pump Driver circuit output low/high
P1452 DMTL Reference current too low
P1453 DMTL Reference current too high
P1482 DMTL heater control circuit Low
P1483 DMTL heater control circuit High
P1582 Flight recorder Data stored
P1624 Security ID ID transfer process failed
P1629 Generator FR line failure
P1632 Generator Charge system failure
P1646 UHEGO sensor bank A Slow activation/ control module open shorted
P1647 UHEGO sensor bank B Slow activation/ control module open shorted
P1670 E Box fan Malfunction low
P1671 E Box fan Malfunction high
P1697 Cruise control Shorter/Longer switch ON fault
P1700 Low gear ratio plausibility check
P2066 Secondary fuel pump Range check
P2070 Manifold valve output drive 1 Performance check stuck open/closed
P2071 Manifold valve output drive 2 Performance check stuck open/closed
P2101 Electric throttle Range performance
P2103 Electric throttle Throttle duty at 100% continuously
P2105 Electric throttle MIL request duel fuel cut off
P2106 Intended reduced availability Reconfiguration failure
P2118 Electric throttle system Over current detection by hardware
P2119 Electric throttle Throttle stuck open
P2122 APP sensor Circuit 2 low input
P2123 APP sensor Circuit 2 high input
P2228 HAC sensor Circuit low
P2229 HAC sensor Circuit high
P2299 Accelerator pedal Brake override
P2401 DMTL Pump Ground short
P2402 DMTL Pump Battery short
P2404 DMTL Pump Noise/reference leak fault
P2450 DMTL COV stuck open
P2451 DMTL COV stuck closed
P2503 Charging system Voltage low
P2504 Charging system Voltage high
P2601 Water pump Performance fault
P2610 Engine off timer Timer malfunction
P2632 Secondary fuel pump driver circuit Output circuit open
P2633 Secondary fuel pump driver circuit Output low
P2634 Secondary fuel pump driver circuit High input
P6365 Primary fuel pump Pump not working when requested
P2636 Secondary fuel pump Low flow/ performance

TERRAIN RESPONSE ™

Terrain Response ™ system allows the driver to select a program which will provide the optimum settings for traction and performance for prevailing terrain conditions.

As part of Terrain Response ™ there will be different throttle pedal progression maps associated with different Terrain Response ™ modes. The two extremes are likely to be a sand map (quick build up of torque with pedal travel) and grass/gravel/snow (very cautious build up of torque).

The TdV6 implementation of throttle progression is based on a fixed blend time. The torque will blend from that on one map to that on the new map (for the same pedal position) over a fixed time. This means blending will always take the same amount of time but when the torque change is small the torque increase over time will be small, whilst if the torque change is greater then the torque increase over time will be steeper. The resulting acceleration of the vehicle will depend on the torque difference between the two maps as well as on the gear and range selected. The worst case blending that could ever occur has been calibrated to match the blend rate for petrol derivatives as closely as possible, so as to give a transparent behaviour to customers.   Ride and Handling Optimization (204-06 Ride and Handling Optimization)


CENTRAL JUNCTION BOX



The ECM is connected to ignition switch I and II. When the ignition is turned on 12V is applied to the Ignition Sense input. The ECM then starts its power up routines and turns on the ECM main relay; the main power to the ECM and it's associated system components. When the ignition is turned OFF the ECM will maintain its powered up state for up to 20 minutes while it initiates its power down routine and on completion will turn off the ECM main relay. The ECM will normally power down in approximately 60 seconds, do not disconcert the battery until the ECM is completely powered down.