Block Diagram
CAN abbreviations
| 15 | Ignition ON (terminal 15) | B148 | Exhaust temperature sensor |
|---|---|---|---|
| 30 | Battery positive (terminal 30) | L2A | Injector, cylinder 1 |
| A40 | Direct ignition, ignition coil | L2B | Injector, cylinder 2 |
| B18 | AC pressure sensor | L2C | Injector, cylinder 3 |
| B30 | Crankshaft pulse pick-up | L2D | Injector, cylinder 4 |
| B39 | Coolant temperature sensor | M8 | Fuel pump sensor |
| B57A | Oxygen sensor 1, catalytic converter control | S41 | Clutch switch |
| B57B | Oxygen sensor 2, catalytic converter control | S87 | Oil pressure switch |
| B67 | Vacuum pipe sensor |
Block Diagram (Continued)
| B22 | Pedal position sensor | B65 | Knock control sensor |
|---|---|---|---|
| B41 | Oil level sensor | G8 | Alternator |
| B64 | Intake air temperature sensor | X97 | Rear electronics module |
Block Diagram (Continued)
| 31 | Ground (terminal 31) | X125 | Engine compartment electronics module |
|---|---|---|---|
| A111 | Throttle valve module | Y123 | Tank vent solenoid valve |
| S216 | Brake light switch |
Function Table
Wiring harness plug X1 = 64-pin, engine side "M"
Wiring harness plug X2 = 64-pin, vehicle side "K"
Wiring harness plug X3 = control unit housing
| Terminal | Description | Source | Destination |
|---|---|---|---|
| X1-4 | Knock sensor | ECM | B65 |
| X1-5 | Oxygen sensor upstream of catalytic converter (signal line) | B57B | ECM |
| X1-6 | Oxygen sensor upstream of catalytic converter (signal line) | ECM | B57B |
| X1-7 | Oxygen sensor downstream of catalytic converter (signal line) | B57A | ECM |
| X1-8 | Coolant temperature sensor (signal line) | B39 | ECM |
| X1-10 | The intake air temperature is registered for calculation of the air mass (signal line) | B64 | ECM |
| X1-11 | Exhaust temperature sensor (signal line) | B148 | ECM |
| X1-12 | The intake air vacuum pressure is registered for calculation of the air mass, MAP sensor (signal line) | B67 | ECM |
| X1-13 | Direct ignition, ignition coil, cylinders 2 & 3 | ECM | A40 |
| X1-15 | Oil pressure sensor | S87 | ECM |
| X1-16 | Input of alternator condition information, "L" terminal | G8 | ECM |
| X1-17 | Tank vent solenoid valve | ECM | Y123 |
| X1-18 | Camshaft sensor | A40 | ECM |
| X1-19 | Oxygen sensor downstream of catalytic converter (signal line) | ECM | B57A |
| X1-23 | Crankshaft sensor | ECM | B30 |
| X1-25 | Throttle valve sensor (signal line, potentiometer 2) | A111 | ECM |
| X1-26 | Crankshaft sensor | B30 | ECM |
| X1-27 | Direct ignition, ignition coil, cylinders 1 & 4 | ECM | A40 |
| X1-28 | Throttle valve sensor (signal line, potentiometer 1) | A111 | ECM |
| X1-29 | The intake air temperature is registered for calculation of the air mass | B64 | ECM |
| X1-30 | Throttle valve sensor (ground, potentiometer 1) | ECM | A111 |
| X1-31 | Throttle valve sensor (ground, potentiometer 2) | ECM | A111 |
| X1-32 | The intake air vacuum pressure is registered for calculation of the air mass, MAP sensor (voltage supply) | ECM | B67 |
| X1-33 | Actuation of injector, cylinder 1 | ECM | L2A |
| X1-34 | Throttle valve sensor (voltage supply, potentiometer 1) | ECM | A111 |
| X1-35 | Throttle valve sensor (voltage supply, potentiometer 2) | ECM | A111 |
| X1-37 | Knock sensor | B65 | ECM |
| X1-38 | Coolant temperature sensor (voltage supply) | B39 | ECM |
| X1-42 | The intake air vacuum pressure is registered for calculation of the air mass, MAP sensor (signal line) | ECM | B67 |
| X1-44 | Voltage supply, sensors | ECM | B18 B148 |
| X1-46 | Throttle valve actuator (ground) | ECM | A111 |
| X1-47 | Throttle valve actuator (voltage supply) | ECM | A111 |
| X1-49 | Actuation of injector, cylinder 2 | ECM | L2B |
| X1-50 | Actuation of injector, cylinder 4 | ECM | L2D |
| X1-51 | Actuation of injector, cylinder 3 | ECM | L2C |
| X1-53 | Exhaust gas recirculation valve (signal line) | ECM | B148 |
| X1-57 | Oxygen sensor upstream of catalytic converter (heating) | ECM | B57B |
| X1-58 | The intake air temperature is registered for calculation of the air mass | ECM | B64 |
| X1-59 | Ground, sensors | ECM | B18 B148 |
| X1-60 | Camshaft sensor (ground) | A40 | ECM |
| X1-62 | Oxygen sensor downstream of catalytic converter (heating) | ECM | B57A |
| X1-63 | Throttle valve actuator (ground) | ECM | A111 |
| X1-64 | Throttle valve actuator (voltage supply) | ECM | A111 |
| X2-1 | Main relay actuation | ECM | UEC |
| X2-7 | AC pressure sensor (signal line) | B18 | ECM |
| X2-10 | Tank capacity sensor | M8 | ECM |
| X2-12 | Pedal position sensor, potentiometer 1 (signal line) | B22 | ECM |
| X2-13 | Pedal position sensor, potentiometer 2 (signal line) | B22 | ECM |
| X2-14 | Brake light switch | S216 | ECM |
| X2-17 | Actuation, fan relay 1 | ECM | UEC |
| X2-19 | Ignition ON (terminal 15) | UEC | ECM |
| X2-20 | Battery positive (terminal 30) | UEC | ECM |
| X2-21 | Ignition key position | CIM | ECM |
| X2-22 | Clutch switch (cruise control) | S41 | ECM |
| X2-24 | Malfunction indicator lamp MIL | ECM | IPC |
| X2-27 | Brake pedal switch | S216 | ECM |
| X2-29 | Pedal position sensor, potentiometer 1 (voltage supply) | ECM | B22 |
| X2-31 | Tank capacity sensor (voltage supply) | ECM | M8 |
| X2-33 | Actuation, fan relay 2 | ECM | UEC |
| X2-34 | Pedal position sensor, potentiometer 1 (ground) | ECM | B22 |
| X2-44 | Pedal position sensor, potentiometer 2 (voltage supply) | ECM | B22 |
| X2-48 | Voltage supply, 12 volts from main relay | UEC | ECM |
| X2-50 | Pedal position sensor, potentiometer 2 (ground) | ECM | B22 |
| X2-51 | Fuel pump relay | ECM | REC |
| X2-52 | AC clutch relay actuation | ECM | UEC |
| X2-54 | The oil quantity is registered | B41 | ECM |
| X2-58 | Starter relay actuation | ECM | UEC |
| X2-61 | Actuation, fan relay 3 | ECM | UEC |
| X2-64 | Voltage supply, 12 volts from main relay | ECM | UEC |
| X3-1 | Ground (terminal 31), control unit housing | Ground | ECM |
| X2-5 X2-6 HSCAN | Input of information regarding ABS status (status of ABS error message) | ABS | ECM |
| X2-5 X2-6 HSCAN | Input of information regarding CIM status (status of immobiliser error message, cruise control buttons) | CIM | ECM |
| X2-5 X2-6 HSCAN | AC status is communicated to other control units via CAN | ECM | CIM |
| X2-5 X2-6 HSCAN | ECM status is communicated to other control units via CAN for function monitoring (network monitoring) | ECM | ABS AHL CIM TCM |
| X2-5 X2-6 HSCAN | The current engine speed and accelerator pedal position is made available to other control units via CAN | ECM | ABS CIM TCM |
| X2-5 X2-6 HSCAN | The current engine coolant temperature is made available to other control units via CAN | ECM | CIM TCM |
| X2-5 X2-6 HSCAN | The current engine torque is made available to other control units via CAN | ECM | ABS TCM |
| X2-5 X2-6 HSCAN | Immobiliser information | ECM | CIM |
| X2-5 X2-6 HSCAN | Immobiliser information | CIM | ECM |
| X2-5 X2-6 HSCAN | Input of information regarding the request for torque reduction | ABS | ECM |
| X2-5 X2-6 HSCAN | Input of information regarding TCM status (transmission emergency operation, gear engaged and selected shift mode) | TCM | ECM TCM CIM |
| X2-5 X2-6 HSCAN | Input of information regarding transmission temperature | TCM | ECM |
| X2-5 X2-6 HSCAN | Input of information regarding the request for torque reduction by TCM | TCM | ECM |
| X2-5 X2-6 HSCAN | Diagnostics – communication with tester | DIAG ECM | ECM DIAG |
| X2-5 X2-6 HSCAN | The current vehicle speed and distance travelled is made available to other control units via CAN | ECM | CIM EHPS |
| X2-5 X2-6 CAN | The ECM receives the wheel speeds for calculating the odometer signal via CAN | ABS | ECM |
| X2-5 X2-6 CAN | The ECM receives the wheel speeds for calculating the vehicle speed signal via CAN | ABS | ECM |
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 handles 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 vehicles without AC, only a suction cooling fan and in vehicles with AC an additional, second suction fan are fitted. The fans can be switched to several settings.
Electronic Accelerator Pedal
The following signals and components bear direct relevance to the observance/fulfilment of the safety regulations for the electronic accelerator pedal. Pedal position sensor 1 (PPS1), pedal position sensor 2 (PPS2), throttle valve sensor 1 (TPS1), throttle valve sensor 2 (TPS2), throttle valve servo motor
Electronic Accelerator Pedal 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 limitation of the permissible throttle valve opening to an applicable maximum value
Limitation of the throttle valve opening speed.
Brake pedal actuation by the driver is evaluated as idling request.
Limitation of the permissible vehicle acceleration by separate application values for each individual transmission gear.
- Emergency operation (power management)
During emergency operation, the current to the throttle valve motor is interrupted. In addition, software functions are implemented, which make possible limited operation of the vehicle via injection suppression, alternating between cylinders (possibly rotating), ignition retardation and/or other torque-reducing functions.
- Increased engine idling (forced idle)
A suitable engine speed is kept constant, regardless of load, i.e. it is controlled by uphill/downhill inclines and various loading conditions.
- Engine off (walk home)
In this case, the ignition and the injection are switched off.