6 LH exhaust CMP sensor 7 LH MAFT sensor 8 LH front knock sensor 9 LH rear knock sensor 10 RH (right hand) rear knock sensor 11 RH front knock sensor 12 RH intake CMP sensor 13 RH exhaust CMP sensor 14 RH MAFT sensor CONTROL DIAGRAM SHEET 2 OF 2
Item Description 1 MAP sensor 2 ECT sensor (ECT 2)
4 Diagnostic socket 5 To other system control modules 6 ECM 7 Electronic throttle 8 APP sensor 9 AAT sensor 10 ECT sensor (ECT 1) 11 LH upstream HO2S 12 LH downstream HO2S 13 MAPT (manifold absolute pressure and temperature) sensor 14 RH downstream HO2S 15 RH upstream HO2S
ECM ADAPTIONS System Operation
The ECM (engine control module) has the ability to adapt the input values it uses to control certain outputs. This capability
maintains engine refinement and ensures the engine emissions remain within the legislated limits. The components which
have adaptions associated with them are:
The APP (accelerator pedal position) sensor
The heated oxygen sensors
The MAFT (mass air flow and temperature) sensors
The CKP (crankshaft position) sensor
Electronic throttle.
OXYGEN AND MAFT SENSORS
There are several adaptive maps associated with the fueling strategy. Within the fueling strategy the ECM calculates short-term adaptions and long term adaptions. The ECM will monitor the deterioration of the heated oxygen sensors 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.
CRANKSHAFT POSITION 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 drive plates 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
drive plate adaption if the ECM is renewed or replaced. The ECM supports four drive plate adaptions for the CKP sensor. Each adaption relates to a specific engine speed range. The engine speed ranges are detailed in the table below:
Adaption 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 legislated emissions limit being exceeded by a given
amount. The second level is a misfire that may cause catalytic converter 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, it 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 catalytic converters. If the number of misfires exceeds a given value, the ECM stores catalytic converter damage fault codes, along with the engine speed, engine load and engine coolant temperature.
The signal from the CKP sensor indicates how fast the poles on the drive plate are passing the sensor tip. A sine wave is generated each time a pole passes the sensor tip. The ECM can detect variations in drive plate 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 CKP sensor and assign a roughness value to it. This roughness value can be viewed within the real time monitoring feature using Jaguar approved
diagnostic equipment. TheECM will evaluate the signal against a number of factors and will decide whether to record the occurrence or ignore it. The ECM can assign a roughness and misfire signal for each cylinder.
DIAGNOSTICS
The ECM stores each fault as a DTC (diagnostic trouble code). The DTC and associated environmental and freeze frame data can be read using Jaguar approved diagnostic equipment, which can also read real time data from each sensor, the adaption
values currently being employed and the current fueling, ignition and idle speed settings.
ENGINE CONTROL MODULE Component Description
The ECM is installed in the front passenger side of the engine compartment, on a bracket attached to the engine bulkhead. The ECM has the capability of adapting its fuel and ignition control outputs in response to several sensor inputs. The ECM receives inputs from the following:
CKP sensor. CMP (camshaft position) sensors (4 off).
ECT (engine coolant temperature) sensor.
Knock sensors (4 off).
MAP (manifold absolute pressure) sensor.
MAFT sensors (2 off). MAPT (manifold absolute pressure and temperature) sensor.
Throttle position sensor.
Heated oxygen sensors (4 off).
APP sensor. Ambient air temperature sensor.
FRP (fuel rail pressure) sensor. For additional information, refer to 303-04G Fuel Charging and Controls.
Engine cooling fan. For additional information, refer to 303-03D Engine Cooling.
Stoplamp switch. For additional information, refer to 206-09 Anti-Lock Control - Stability Assist.
Speed control cancel/suspend switch. For additional information, refer to 310-03D Speed Control.
Oil level and temperature sensor. For additional information, refer to 303-01F Engine.
Fuel LP (low pressure) sensor. For additional information, refer to 310-01D Fuel Tank and Lines.
Fuel pump driver module. For additional information, refer to 310-01D Fuel Tank and Lines.
The ECM provides outputs to the following: Electronic throttle.
Main relay.
Heater elements of the heated oxygen sensors (4 off).
Fuel injectors (8 off). For additional information, refer to 303-04G Fuel Charging and Controls. www.JagDocs.com
Defaults to base mapping for the ignition timing, with no cylinder correction
Disables the VCT system.
ENGINE COOLANT TEMPERATURE SENSORS
The ECT sensors are NTC (negative temperature coefficient) thermistors that allow the ECM to monitor the engine coolant temperature.
There are two identical ECT sensors installed, which are identified as ECT 1 and ECT 2. Each sensor is secured with a twist-lock and latch mechanism, and is sealed with an O-ring. A two pin electrical connector provides the interface between the sensor
and the engine harness.
ECT 1
ECT 1 is installed in the heater manifold, at the rear of the RH (right-hand) cylinder head. The input from this sensor is used in
calibration tables and by other systems.
ECT 2
ECT 2 is installed in the lower hose connector which attaches to the bottom of the thermostat. The input from this sensor is
used for OBD (on-board diagnostic) 2 diagnostics and, in conjunction with the input from ECT 1, to confirm that the thermostat
is functional.
KNOCK SENSORS
The knock sensors are piezo-ceramic sensors that allow the ECM to employ active knock control and prevent engine damage from pre-ignition or detonation.
Two knock sensors are installed on the inboard side of each cylinder head, one mid-way between cylinders 1 and 2, and one
mid-way between cylinders 3 and 4. Each knock sensor is secured with a single screw. On each knock sensor, a two pin
electrical connector provides the interface with the engine harness.
The ECM compares the signals from the knock sensors with mapped values stored in memory to 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.
The ECM cancels closed loop control of the ignition system if the signal received from a knock sensor becomes implausible. In these circumstances the ECM defaults to base mapping for the ignition timing. This ensures the engine will not become damaged if low quality fuel is used. The MIL (malfunction indicator 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.
MANIFOLD ABSOLUTE PRESSURE SENSOR
The MAP sensor allows the ECM to calculate the load on the engine, which is used in the calculation of fuel injection time.
The MAP sensor is installed in the air inlet of the SC (supercharger). The sensor is secured with a single screw and sealed with an O-ring. A three pin electrical connector provides the interface with the engine harness.
If the MAP sensor fails, the ECM adopts a default value of 1 bar (14.5 lbf/in.2
). With a failed MAP sensor, the engine will suffer from poor starting, rough running and poor driveability.
MASS AIR FLOW AND TEMPERATURE SENSORS
The MAFT sensors allow the ECM to measure the mass and the temperature of the air flow into the engine. The mass air flow is measured with a hot film element in the sensor. The temperature of the air flow is measured with a NTC thermistor in the sensor. The mass air flow is used to determine the fuel quantity to be injected in order to maintain the stoichiometric air/fuel
mixture required for correct operation of the engine and the catalytic converters.
There are two MAFT sensors installed, one in each air cleaner outlet duct. Each MAFT sensor is secured with two screws and sealed with an O-ring. On each MAFT sensor, a five pin electrical connector provides the interface with the engine harness.
If the hot film element signal fails the ECM invokes a software backup strategy to calculate the mass air flow from other inputs. Closed loop fuel control, closed loop idle speed control and evaporative emissions control are discontinued. The engine
will suffer from poor starting, poor throttle response and, if the failure occurs while driving, the engine speed may dip before
recovering.
If the NTC thermistor signal fails the ECM adopts a default value of 25 °C (77 °F) for the intake air temperature.
MANIFOLD ABSOLUTE PRESSURE AND TEMPERATURE SENSOR
The MAPT sensor allows the ECM to calculate the air charge density immediately before it enters the cylinders. This is used to adjust the ignition timing relative to the boost pressure, and to monitor the performance of the charge air coolers.
The MAPT sensor is installed in the rear of the LH intake manifold. The sensor is secured with a single screw and sealed with an O-ring. A four pin electrical connector provides the interface with the engine harness.
THROTTLE POSITION SENSORS
The TP (throttle position) sensors allow the ECM to determine the position and angular rate of change of the throttle blade. There are two TP sensors located in the electronic throttle. See below for details of the electronic throttle. If aTP sensor fails, the ECM:
Adopts a limp home mode where engine speed is limited to a maximum of approximately 2000 rev/min
Discontinues evaporative emissions control
Discontinues closed loop control of engine idle speed.
With a failed TP sensor, the engine will suffer from poor running and throttle response.
HEATED OXYGEN SENSORS
Item Description A Upstream heated oxygen sensor B Downstream heated oxygen sensor The heated oxygen sensors allow the ECM to measure the oxygen content of the exhaust gases, for closed loop control of the fuel:air mixture and for catalytic converter monitoring.
An upstream heated oxygen sensor is installed in the outlet of each exhaust manifold, which enables independent control of
the fuel:air mixture for each cylinder bank. A downstream heated oxygen sensor is installed in each catalytic converter, which
enables the performance of the catalytic converters to be monitored.
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 (pulse width modulation) signal from the ECM. The heater elements are operated immediately after each engine start and during low load conditions when the temperature of the
exhaust gases is insufficient to maintain the required sensor temperature. The PWM duty cycle is carefully controlled to prevent thermal shock to cold sensors. A non-functioning heater delays the sensor’s readiness for closed loop control and
increases emissions.
The upstream heated oxygen sensors produce a constant voltage, with a variable current that is proportional to the lambda
ratio. The downstream heated oxygen sensors produce an output voltage dependant on the ratio of the exhaust gas oxygen to
around the vehicle. The ECM uses the AAT input for a number of functions, including engine cooling fan control. The ECM also transmits the ambient temperature on the high speed CAN bus for use by other control modules.
The AAT sensor is installed in the LH (left-hand) exterior mirror, with the bulb of the sensor positioned over a hole in the
bottom of the mirror casing.
The ECM supplies the sensor with a 5 V reference voltage and a ground, and translates the return signal voltage into a temperature.
If there is a fault with the AAT sensor, the ECM calculates the AAT from the temperature inputs of the MAFT sensors. If the AAT sensor and the temperature inputs of the MAFT sensors are all faulty, the ECM adopts a default ambient temperature of 20 °C (68 °F).
ELECTRONIC THROTTLE
The ECM uses the electronic throttle to regulate engine torque.
The electronic throttle is installed between the T piece duct, of the intake air distribution and filtering system, and the inlet of
the SC. For additional information, refer to 303-12F Intake Air Distribution and Filtering.
The throttle plate is operated by an electric DC (direct current) motor integrated into the throttle body. The ECM uses a PWM signal to control the DC motor. The ECM compares the APP sensor inputs against an electronic map to determine the required position of the throttle plate. The ECM and electronic throttle are also required to: Monitor requests for cruise control operation
Automatically operate the electronic throttle for accurate cruise control
Perform all dynamic stability control engine interventions
Monitor and carry out maximum engine speed and road speed cut outs
Provide different engine maps for the ride and handling optimization system.
A software strategy within the ECM calibrates the position of the throttle plate at the beginning of each ignition cycle. When the ignition is turned on, the ECM performs a self test and calibration routine by fully closing the throttle plate and then opening it again. This tests the default position springs and allows the ECM to learn the position of the closed hard stop. Subsequently the ECM keeps the throttle plate a minimum of 0.5 degree from the closed hard stop. AMBIENT AIR TEMPERATURE SENSOR
Published: 11-May-2011
Electronic Engine Controls - V8 S/C 5.0L Petrol - Manifold Absolute Pressure
(MAP) Sensor
Removal and Installation
Removal
NOTE: Removal steps in this procedure may contain installation details.
1. Refer to: Engine Cover - V8 5.0L Petrol/V8 S/C 5.0L Petrol (501-05 Interior Trim and Ornamentation, Removal and Installation).
2. Refer to: Cowl Vent Screen (501-02 Front End Body Panels, Removal and Installation).
3. NOTE: Some variation in the illustrations may occur, but
the essential information is always correct.
Torque: 10 Nm
4. NOTE: Some variation in the illustrations may occur,
but the essential information is always correct.