Discovery Series II & Range Rover

The Engine Control Module (ECM) is a Bosch Motronic 5.2.1 which is mounted in a plastic E-box located on the left side of engine compartment, under cruise control actuator. The ECM is cooled by a dedicated fan, which supplies cabin air into the plastic E-box. The operating temperature of the ECM is monitored by an internal temperature sensor.

ECM uses a flash, electronic erasable programmable read only memory (EEPROM). This enables ECM to be externally configured, ensuring that ECM can be updated as necessary and configured with market specific data. Land Rover TestBook must be used to configure replacement ECM. ECM can be reconfigured as many times as is necessary to meet changing specifications and legislation.

ECM stores crankshaft and camshaft positions when the engine has stopped based on CKP and CMP sensors. This allows immediate sequential fuel injection and ignition timing during engine cranking. This information is lost if battery voltage is too low or disconnected. This function will be disabled during the first engine start.

ECM uses sensor data, engine operating data and information stored in an internal memory map to control fuel, ignition and some emissions functions. The ECM monitors performance of the engine for misfires, catalyst efficiency, exhaust leaks and EVAP control loss. If a fault is detected, the ECM stores a Diagnostic Trouble Code (DTC) and illuminates the Malfunction Indicator Light (MIL). The system incorporates default strategies for some sensor failures which will enable the engine to operate in the event of a sensor failure. See suspect component listed under INPUT DEVICES  for description of default strategies, if available. A fault is indicated by illumination of the Maintenance Indicator Light (MIL).

The ECM also communicates with the:

• With TestBook via diagnostic connector.
• Electronic Automatic Transmission (EAT) ECU using a Controller Area Network (CAN) data link.
• Body Electrical Control Module (BECM).
• Self-Leveling and Anti-Lock Braking System (SLABS) ECU on Discovery Series II.
• Transfer Box ECU.
• Anti-Lock Braking System (ABS) ECU on Range Rover.