Block Diagram
CAN abbreviations
| 15 | Ignition ON ( terminal 15) | A40A | Direct ignition, ignition coil |
|---|---|---|---|
| 30 | Battery positive (terminal 30) | A40B | Direct ignition, ignition coil |
| B65 | Knock control sensor 1 | L2A | Injector, cylinder 3 |
| B65L | Knock control sensor 2 | L2B | Injector, cylinder 2 |
| B102 | Hot film mass air flow meter | L2C | Injector, cylinder 1 |
| B39 | Coolant temperature sensor | L2D | Injector, cylinder 4 |
| B18 | AC pressure sensor | L2E | Injector, cylinder 5 |
| B28 | Camshaft sensor | L2F | Injector, cylinder 6 |
| B41 | Oil level sensor | Y21A | Variable intake pipe switchover valve |
Block Diagram (Continued)
| A111 | Throttle valve module | B57R | Oxygen sensor, catalytic converter control |
|---|---|---|---|
| B166 | Oxygen sensor, mixture regulation, heated | M8 | Tank capacity sensor |
| B22 | Pedal position sensor | X125 | Engine compartment electronics module |
| B44 | Engine speed sensor | Y123 | Tank vent solenoid valve |
| B57L | Oxygen sensor, catalytic converter control |
Block Diagram (Continued)
| G8 | Alternator | S87 | Oil pressure switch |
|---|---|---|---|
| S216 | Brake light switch | X97 | Rear electronics module |
| S41 | Clutch switch |
Function Table
Wiring harness plug X1 = 64-pin, engine side "M"
Wiring harness plug X2 = 64-pin, vehicle side "K"
| Terminal | Description | Source | Destination |
|---|---|---|---|
| X1-1 | Throttle valve actuator (ground) | ECM | A111 |
| X1-2 | Oxygen sensor 2 downstream of catalytic converter (heating) | ECM | B57L |
| X1-3 | Injector, cylinder 3 | ECM | L2A |
| X1-4 | Intake pipe switchover | ECM | Y21A |
| X1-5 | Actuation of fuel vent valve | ECM | Y123 |
| X1-6 | Engine knocking is detected by means of a piezo element (sensor 2) | ECM | B65L |
| X1-7 | Oxygen sensor 2 downstream of catalytic converter (signal line) | B57L | ECM |
| X1-8 | Camshaft sensor (signal line) | B28 | ECM |
| X1-10 | The engine speed is registered via a sensor | B44 | ECM |
| X1-11 | The oil quantity is registered | B41 | ECM |
| X1-12 | Oxygen sensor 2 upstream of catalytic converter (signal line) | B166 | ECM |
| X1-14 | Direct ignition, ignition coil, cylinder 5 | ECM | A40A |
| X1-15 | Direct ignition, ignition coil, cylinder 3 | ECM | A40A |
| X1-16 | Direct ignition, ignition coil, cylinder 1 | ECM | A40A |
| X1-17 | Throttle valve actuator (voltage supply) | ECM | A111 |
| X1-18 | Oxygen sensor 2 upstream of catalytic converter (heating) | ECM | B166 |
| X1-19 | Injector, cylinder 1 | ECM | L2C |
| X1-20 | Injector, cylinder 5 | ECM | L2E |
| X1-22 | Engine knocking is detected by means of a piezo element (sensor 1) | B65 | ECM |
| X1-23 | Oxygen sensor 1 downstream of catalytic converter (signal line) | B57R | ECM |
| X1-24 | Throttle valve sensor (signal line, sensor 1) | A111 | ECM |
| X1-25 | Coolant temperature sensor | B39 | ECM |
| X1-26 | Ground, sensors | ECM | B102 B39 B18 B28 |
| X1-28 | Oxygen sensor 1 upstream of catalytic converter (signal line) | B166 | ECM |
| X1-29 | The oil pressure is registered | S87 | ECM |
| X1-30 | Direct ignition, ignition coil, cylinder 6 | ECM | A40B |
| X1-31 | Direct ignition, ignition coil, cylinder 4 | ECM | A40B |
| X1-32 | Direct ignition, ignition coil, cylinder 2 | ECM | A40B |
| X1-33 | Throttle valve actuator (ground) | ECM | A111 |
| X1-34 | Oxygen sensor 1 downstream of catalytic converter (heating) | ECM | B57R |
| X1-35 | Injector, cylinder 2 | ECM | L2B |
| X1-36 | Injector, cylinder 6 | ECM | L2F |
| X1-38 | Engine knocking is detected by means of a piezo element (sensor 2) | B65L | ECM |
| X1-39 | Oxygen sensor 2 downstream of catalytic converter (signal line) | B57L | ECM |
| X1-40 | Throttle valve sensor (signal line, sensor 2) | A111 | ECM |
| X1-42 | Throttle valve sensor (ground) | ECM | A111 |
| X1-44 | Oxygen sensor 2 upstream of catalytic converter (signal line) | B166 | ECM |
| X1-49 | Throttle valve actuator (voltage supply) | ECM | A111 |
| X1-50 | Oxygen sensor 1 upstream of catalytic converter (heating) | ECM | B166 |
| X1-51 | Voltage supply for sensors, 5 volts | ECM | B102 B39 B18 |
| X1-52 | Injector, cylinder 4 | ECM | L2D |
| X1-54 | Engine knocking is detected by means of a piezo element (sensor 1, ground) | ECM | B65 |
| X1-55 | Oxygen sensor 1 downstream of catalytic converter (signal line) | B57R | ECM |
| X1-56 | The intake air temperature is registered for calculation of the air mass (signal line) | B102 | ECM |
| X1-57 | The intake air temperature is registered for calculation of the air mass (signal line) | B102 | ECM |
| X1-58 | Throttle valve sensor (voltage supply) | ECM | A111 |
| X1-59 | The engine speed is registered via a sensor | ECM | B44 |
| X1-60 | Oxygen sensor 1 upstream of catalytic converter (signal line) | B166 | ECM |
| X1-62 | Ground for electronics | ECM | |
| X2-6 | The AC refrigerant pressure is registered (signal line) | B18 | ECM |
| X2-7 | Pedal position sensor 2 (voltage supply) | ECM | B22 |
| X2-8 | Pedal position sensor 1 (signal line) | B22 | ECM |
| X2-11 | Alternator status, "L" terminal | G8 | ECM |
| X2-13 | Actuation of AC compressor relay | ECM | UEC |
| X2-15 | Battery positive (terminal 30) | UEC | ECM |
| X2-16 | Voltage supply, 12 volts from main relay | UEC | ECM |
| X2-21 | Clutch switch (cruise control) | S41 | ECM |
| X2-24 | Pedal position sensor 1 (ground) | ECM | B22 |
| X2-25 | Pedal position sensor 2 (ground) | ECM | B22 |
| X2-26 | Brake pedal switch | S216 | ECM |
| X2-27 | Brake light switch | S216 | ECM |
| X2-30 | Relay actuation, fuel pump | ECM | REC |
| X2-31 | After recognition of "Ignition ON", the main relay is actuated | ECM | UEC |
| X2-32 | Voltage supply, 12 volts from main relay | UEC | ECM |
| X2-33 | Actuation, fan relay 2 | ECM | UEC |
| X2-34 | Tank capacity sensor (ground) | ECM | M8 |
| X2-38 | Tank capacity sensor (signal line) | M8 | ECM |
| X2-39 | Starter relay actuation | ECM | UEC |
| X2-40 | Pedal position sensor 2 (signal line) | B22 | ECM |
| X2-46 | Malfunction indicator lamp MIL | ECM | IPC |
| X2-47 | Ignition ON (terminal 15) | UEC | ECM |
| X2-48 | Voltage supply, 12 volts from main relay | UEC | ECM |
| X2-50 | Actuation, fan relay 1 | ECM | UEC |
| X2-51 | Ground, sensors | ECM | B102 B18 |
| X2-56 | Pedal position sensor 1 (voltage supply) | ECM | B22 |
| X2-62 | Actuation, fan relay 3 | ECM | UEC |
| X2-64 | Ignition key position | CIM | ECM |
| X2-12 X2-29 HSCAN | Input of information regarding ABS status (status of ABS error message) | ABS | ECM |
| X2-12 X2-29 HSCAN | Input of information regarding CIM status (status of immobiliser error message, cruise control buttons) | CIM | ECM |
| X2-12 X2-29 HSCAN | AC status | ECM | CIM |
| X2-12 X2-29 HSCAN | ECM status is communicated to other control units via CAN for function monitoring (network monitoring) | ECM | ABS AHL CIM EHPS TCM |
| X2-12 X2-29 HSCAN | The current engine speed and accelerator pedal position is made available to other control units via CAN | ECM | ABS CIM EPS TCM |
| X2-12 X2-29 HSCAN | The current engine coolant temperature is made available to other control units via CAN | ECM | CIM TCM |
| X2-12 X2-29 HSCAN | The current engine torque is made available to other control units via CAN | ECM | ABS TCM |
| X2-12 X2-29 HSCAN | Immobiliser information | ECM | CIM |
| X2-12 X2-29 HSCAN | Immobiliser information | CIM | ECM |
| X2-12 X2-29 HSCAN | Input of information via the request for torque reduction by ABS with TCS | ABS | ECM |
| X2-12 X2-29 HSCAN | Input of information regarding TCM status (transmission emergency operation, gear engaged and selected shift mode) | TCM | ECM |
| X2-12 X2-29 HSCAN | Input of information regarding transmission temperature | TCM | ECM |
| X2-12 X2-29 HSCAN | Input of information regarding the request for torque reduction by TCM | TCM | ECM |
| X2-12 X2-29 HSCAN | Diagnostics – communication with tester | DIAG ECM | ECM DIAG |
| X2-12 X2-29 HSCAN | The current vehicle speed and distance travelled is made available to other control units via CAN | ECM | CIM EHPS |
| X2-12 X2-29 HSCAN | The ECM receives the wheel speeds for calculating the odometer signal via CAN | ABS | ECM |
| X2-12 X2-29 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 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.
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.