Block Diagram
CAN abbreviations
| 15 | Ignition ON (terminal 15) | B65 | Knock control 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 |
| B28 | Camshaft sensor | L2D | Injector, cylinder 4 |
| B30 | Crankshaft pulse pick-up | M8 | Fuel pump sensor |
| B39 | Coolant temperature sensor | S41 | Clutch switch |
| B56 | Heated oxygen sensor, mixture regulation | S87 | Oil pressure switch |
| B57 | Oxygen sensor, catalytic converter control |
Block Diagram (Continued)
| B22 | Pedal position sensor | G8 | Alternator |
|---|---|---|---|
| B41 | Oil level sensor | X97 | Rear electronics module |
| B64 | Intake air temperature sensor | Y56 | Exhaust gas recirculation solenoid valve |
Block Diagram (Continued)
| 31 | Ground (terminal 31) | S216 | Brake light switch |
|---|---|---|---|
| A111 | Throttle valve module | X125 | Engine compartment electronics module |
| B102 | Hot film mass air flow meter | Y123 | Tank vent solenoid valve |
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 |
|---|---|---|---|
| X1-1 | Voltage supply, sensors (ground) | ECM | B18 B28 B39 B41 Y56 |
| X1-2 | The intake air temperature is registered for calculation of the air mass | ECM | B64 |
| X1-3 | Throttle valve sensor (voltage supply, potentiometer 2) | ECM | A111 |
| X1-5 | Crankshaft sensor (ground) | B30 | ECM |
| X1-8 | Oxygen sensor upstream of catalytic converter (ground) | B57 | ECM |
| X1-9 | Exhaust gas recirculation valve (input signal) | Y56 | ECM |
| X1-10 | Throttle valve sensor (signal line, potentiometer 1) | A111 | ECM |
| X1-11 | Camshaft sensor (signal line) | B28 | ECM |
| X1-12 | Actuation of injector, cylinder 4 | ECM | L2D |
| X1-13 | Throttle valve actuator (ground) | ECM | A111 |
| X1-15 | Direct ignition, ignition coil, cylinder 1 | ECM | A40 |
| X1-16 | Direct ignition, ignition coil, cylinder 4 | ECM | A40 |
| X1-17 | Knock sensor (signal line) | B65 | ECM |
| X1-18 | Oxygen sensor downstream of catalytic converter (heating) | ECM | B30 |
| X1-19 | Oxygen sensor upstream of catalytic converter (heating) | ECM | B57 |
| X1-20 | Throttle valve sensor (voltage supply, potentiometer 1) | ECM | A111 |
| X1-23 | Actuation of exhaust gas recirculation valve | ECM | B64 Y56 |
| X1-24 | Oxygen sensor downstream of catalytic converter (ground) | B56 | ECM |
| X1-25 | Coolant temperature sensor (signal line) | B39 | ECM |
| X1-26 | Throttle valve sensor (ground, potentiometer 2) | A111 | ECM |
| X1-27 | Hot film mass air flow meter (ground, temperature sensor) | ECM | B102 |
| X1-29 | Actuation of injector, cylinder 1 | ECM | L2A |
| X1-30 | Throttle valve actuator (voltage supply) | ECM | A111 |
| X1-31 | Direct ignition, ignition coil, cylinder 2 | ECM | A40 |
| X1-32 | Direct ignition, ignition coil, cylinder 3 | ECM | A40 |
| X1-33 | Screened wiring for sensors | ECM | B30 B56 B57 B65 |
| X1-34 | Actuation of fuel vent valve | ECM | Y123 |
| X1-35 | Oxygen sensor upstream of catalytic converter (heating) | ECM | B57 |
| X1-37 | Crankshaft sensor (voltage supply) | ECM | B30 |
| X1-40 | Oxygen sensor downstream of catalytic converter (signal line) | ECM | B56 |
| X1-41 | Hot film mass air flow meter (signal line, temperature sensor) | B102 | ECM |
| X1-42 | Throttle valve sensor (ground, potentiometer 1) | ECM | A111 |
| X1-43 | Hot film mass air flow meter (signal line) | B102 | ECM |
| X1-44 | Actuation of injector, cylinder 3 | ECM | L2C |
| X1-45 | Throttle valve actuator (ground) | ECM | A111 |
| X1-47 | Direct ignition, ignition coil, cylinder 1 | ECM | A40 |
| X1-48 | Direct ignition, ignition coil, cylinder 4 | ECM | A40 |
| X1-49 | Knock sensor (voltage supply) | ECM | B65 |
| X1-51 | Oxygen sensor downstream of catalytic converter (heating) | ECM | B56 |
| X1-52 | Voltage supply, sensors | ECM | B18 B28 B39 Y56 |
| X1-55 | Actuation of exhaust gas recirculation valve (ground) | ECM | Y56 |
| X1-57 | Oxygen sensor upstream of catalytic converter (signal line) | ECM | B57 |
| X1-58 | Throttle valve sensor (ground, potentiometer 2) | ECM | A111 |
| X1-59 | The oil quantity is registered (signal line) | B41 | ECM |
| X1-60 | The oil pressure is registered (signal line) | S87 | ECM |
| X1-61 | Actuation of injector, cylinder 2 | ECM | L2B |
| X1-62 | Throttle valve actuator (voltage supply) | ECM | A111 |
| X1-63 | Direct ignition, ignition coil, cylinder 2 | ECM | A40 |
| X1-64 | Direct ignition, ignition coil, cylinder 3 | ECM | A40 |
| X2-7 | The AC refrigerant pressure is registered | B18 | ECM |
| X2-8 | Pedal position sensor, potentiometer 1 (signal line) | B22 | ECM |
| X2-10 | Clutch switch (cruise control) | S41 | ECM |
| X2-14 | Malfunction indicator lamp MIL | ECM | IPC |
| X2-19 | Fuel pump relay | ECM | REC |
| X2-24 | Pedal position sensor, potentiometer 2 (signal line) | B22 | ECM |
| X2-26 | Input of alternator condition information, "L" terminal | G8 | ECM |
| X2-28 | Brake light switch (signal line) | S216 | ECM |
| X2-29 | Actuation, fan relay 2 | ECM | UEC |
| X2-30 | Actuation, fan relay 1 | ECM | UEC |
| X2-31 | Voltage supply, 12 volts to main relay | UEC | ECM |
| X2-32 | Battery positive (terminal 30) | UEC | ECM |
| X2-36 | Main relay actuation | ECM | UEC |
| X2-39 | Pedal position sensor, potentiometer 1 (voltage supply) | ECM | B22 |
| X2-40 | Pedal position sensor, potentiometer 1 (ground) | ECM | B22 |
| X2-42 | Brake test sensor (signal line) | S216 | ECM |
| X2-45 | Starter relay | ECM | UEC |
| X2-46 | Actuation, fan relay 3 | ECM | UEC |
| X2-47 | Voltage supply, 12 volts to main relay | UEC | ECM |
| X2-51 | Actuation of AC compressor relay | ECM | UEC |
| X2-55 | Pedal position sensor, potentiometer 2 (voltage supply) | ECM | B22 |
| X2-56 | Pedal position sensor, potentiometer 2 (ground) | ECM | B22 |
| X2-57 | Tank capacity sensor (signal line) | M8 | ECM |
| X2-63 | Ignition key position | CIM | ECM |
| X2-64 | Ignition ON (terminal 15) | UEC | ECM |
| X3-1 | Ground (terminal 31) | Ground | ECM |
| X2-38 X2-6 HSCAN | Input of information regarding ABS status (status of ABS error message) | ABS | ECM |
| X2-38 X2-6 HSCAN | Input of information regarding CIM status (status of immobiliser error message, cruise control buttons) | CIM | ECM |
| X2-38 X2-6 HSCAN | AC status is communicated to other control units via CAN | ECM | CIM |
| X2-38 X2-6 HSCAN | ECM status is communicated to other control units via CAN for function monitoring (network monitoring) | ECM | ABS AHL CIM EHPS TCM |
| X2-38 X2-6 HSCAN | The current engine speed and accelerator pedal position is made available to other control units via CAN | ECM | ABS CIM EHPS TCM |
| X2-38 X2-6 HSCAN | The current engine coolant temperature is made available to other control units via CAN | ECM | CIM TCM |
| X2-38 X2-6 HSCAN | The current engine torque is made available to other control units via CAN | ECM | ABS TCM |
| X2-38 X2-6 HSCAN | Immobiliser information | CIM ECM | ECM CIM |
| X2-38 X2-6 CAN | Input of information via the request for torque reduction by ABS with TCS | ABS | ECM |
| X2-38 X2-6 HSCAN | Input of information regarding TCM status (transmission emergency operation, gear engaged and selected shift mode) | TCM | ABS ECM CIM |
| X2-38 X2-6 HSCAN | Input of information regarding transmission temperature | TCM | ECM |
| X2-38 X2-6 HSCAN | Input of information regarding the request for torque reduction by TCM | TCM | ECM |
| X2-38 X2-6 HSCAN | Diagnostics – communication with tester | DIAG ECM | ECM DIAG |
| X2-38 X2-6 HSCAN | The current vehicle speed and distance travelled is made available to other control units via CAN | ECM | CIM EHPS |
| X2-38 X2-6 HSCAN | The ECM receives the wheel speeds for calculating the odometer signal via CAN | ABS | ECM |
| X2-38 X2-6 HSCAN | 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 general, one suction cooling fan is installed in vehicles. 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.