Engine Control Module (ECM)

Engine Control Module (ECM)
The engine control module (ECM) is located on the RH side A post below the face panel inside the vehicle. It has a cast aluminium case and is mounted on a bracket. The ECM has 5 independent connectors totalling 134 pins.

The ECM is available in 4 variants:
^ NAS.
^ NAS low emission vehicles.
^ UK/Europe/Japan/Australia.
^ ROW/Gulf.

The ECM uses a 'flash' electronic erasable programmable read only memory (EEPROM). This enables the ECM to be externally configured, to ensure that the ECM can be updated with any new information, this also allows the ECM to be configured with market specific data. TestBook must be used to configure replacement ECM's. The ECM can be reconfigured up to 16 times to meet changing specifications and legislation.

The ECM memorises the positions of the crankshaft and the camshaft when the engine has stopped via the CKP and CMP sensors. This allows immediate sequential fuel injection and ignition timing during cranking. This information is lost if battery voltage is too low (i.e. flat battery). So the facility will be disabled for the first engine start.

Input/Output
The ECM has various sensors fitted to the engine to allow it to monitor engine condition. The ECM processes these signals and decides what actions to carry out to maintain optimum engine operation by comparing the information from these signals to mapped data within its memory.

Connector 1 (C0634): This connector contains 9 pins and is used primarily for ECM power input and earth. The ECM requires a permanent battery supply, if this permanent feed is lost i.e. the battery discharges or is disconnected the ECM will lose its adapted values and its Diagnostic Trouble Codes (DTC). These adapted values are a vital part of the engine management's rolling adaptive strategy. Without an adaptive strategy, driveability, performance, emission control, and fuel consumption are adversely affected. The ECM can be damaged by high voltage inputs, so care must be taken when removing and replacing the ECM.

Pin Out Details Connector C0634:

Connector 2 (C0635): This connector contains 24 pins and is primarily used for Heated Oxygen Sensors (HO2S) control and earth. The HO2S sensors require a heater circuit to assist in heating the tip of the sensors to enable closed loop fuelling to be implemented quickly after cold starting.

Pin Out Details Connector C0635:

Connector 3 (C0636): This connector contains 52 pins and is used for most sensor and actuator inputs and outputs. Sensor and actuator control is vital to ensure that the ECM maintains adaptive strategy

Pin Out Details Connector C0636 - Part 1 Of 2:

Pin Out Details Connector C0636 - Part 2 Of 2:

Connector 4 (C0637): This connector contains 40 pins and facilitates use of TestBook via the Diagnostic connector. Also contained in this connector is the Malfunction Indicator Lamp (MIL), this instrument panel lamp informs the driver of concerns within the engine management system.

Pin Out Details Connector C0637:

Connector 5 (C0638): This connector contains 9 pins and is used to control the ignition system. The ignition coils are supplied with power and a switching earth completes the circuit.