Engine Control Unit ECM Y 20 DTH / Y 22 DTR - Function Opel Vectra C

Block Diagram, Y 20 Dth / Y 22 Dtr

CAN abbreviations

Block Diagram, Y 20 Dth / Y 22 Dtr (Continued)

Block Diagram, Y 20 Dth / Y 22 Dtr (Continued)

Function Table

Wiring harness plug X1 = 56-pin, engine side "M"

Wiring harness plug X2 = 56-pin, vehicle side "K"

Functional Description

The following new functions have been integrated in the engine control unit and are output to the CAN bus by the ECM:

• Oil level check
• Fuel level check
• Vehicle speed calculation
• ECO Service flex data calculation

Storage of Diagnosis Fault Codes

In order to conform to the statutory EOBD requirements for vehicle self-diagnosis, a so-called freeze frame is stored. This serves to record the operating conditions during recognition of the exhaust emissions-related faults in the engine control. This is performed upon the first exhaust emissions-related fault after initial operation of the vehicle, e.g. after erasing the fault memory. The freeze frame contains data which must be stored in order to record the engine operating conditions as defined by statutory legislation.

Engine Malfunction Telltale and Service Telltale (MIL, Svs)

The self-diagnosis provisions in each engine control unit include two diagnosis telltales, the malfunction indicator lamp MIL (exhaust emissions-related faults) and the service telltale SVS (remaining, non exhaust emissions-related faults).

Immobiliser

The CIM acts as an interface between the ECM, the transponder in the key and the various other control units, the identification of which is employed to determine engine starting authorisation. The CIM begins with the identification as soon as the ignition key is inserted in the ignition lock. When the ignition is switched ON, the ECM transmits information to the CIM and receives information regarding the validity of the transponder key used and the validity of the identification of other control units installed in the vehicle. If the security code from the CIM is correct, the ECM sends an engine start signal to the starter relay. In the case of an error, no start request is enabled by the ECM and a fault code is stored in the ECM.

See also Chapter: Immobiliser – function

Cruise Control

See Chapter: Cruise control – function

Engine Cooling and AC Compressor – Control

The engine control is responsible for the complete engine cooling and AC management in the vehicle, i.e. the radiator fan control, depending on the engine coolant temperature and the system pressure in the AC, as well as the AC compressor control. In general, two suction cooling fans are installed in the vehicle. The fans can be switched to several settings.

Emergency Operation Modes

With a view to maximum availability for the driver, various emergency operation modes are available, depending on the particular fault recognised:

Emergency operation "reduced power": Limitation of the permissible vehicle acceleration for each individual transmission gear. Brake pedal actuation by the driver is evaluated as idling request.

Emergency operation "power management": Software functions are contained in the control unit, which make possible limited operation of the vehicle via injection suppression, alternating between cylinders or other torque-reducing functions.

Increased engine idling "forced idle": A pre-determined engine speed is held constant, irrespective of load.

Engine OFF "walk home": In this case, the injection is deactivated.