Impact of bus faults
If individual bus signals fail that are not stored in the fault code memory
Possible fault symptom or perception on failure of the corresponding bus signal |
Faulty or missing signal |
Transmitter control unit |
|---|---|---|
No EGS function |
Key_in_ignition_status |
CAS |
Terminal 15 not detected |
Terminal_15_status |
CAS |
P not automatically engaged |
FAT_door_switch_status |
CAS |
Substitute programme (electronic emergency mode) no gear engageable |
Engine_speed |
DME1 |
Substitute programme (electronic emergency mode) |
DME_alive_torque |
DME1 |
Substitute programme (electronic emergency mode) |
DME_torque_checksum |
DME1 |
Substitute programme (electronic emergency mode) |
Actual_torque |
DME1 |
Substitute programme (electronic emergency mode) |
Engine_speed_error |
DME1 |
Unwanted gear changes |
Engine_air_pressure |
DME1 |
No gear engageable |
DME1_brake_pedal_contact_status |
DME1 |
Substitute gear shift programme |
Cruise_control_status |
DME1 |
Forced to stay in current gear shift programme |
Warmup_switch_status |
DME1 |
Incorrect gear shift programme |
Accelerator_pedal_angle |
DME1 |
Vehicle rolls back unexpectedly on uphill gradient |
Brake pressure |
DSC |
Unwanted gear changes |
Gear_shift_intervention_request |
DSC |
Corners and gradients not detected |
DSC_longitudinal_acceleration |
DSC |
Corners and gradients not detected |
DSC_lateral_acceleration |
DSC |
Corners not detected/no L-R speed delta/no gear engageable |
Rear_left_wheel_speed |
DSC |
Corners not detected/no L-R speed delta/no gear engageable |
Rear_right_wheel_speed |
DSC |
Unwanted gear changes (gear shift intervention) |
Front_left_wheel_speed |
DSC |
Unwanted gear changes (gear shift intervention) |
Front_right_wheel_speed |
DSC |
No gear engageable |
Brake_pedal_contact_status |
DSC |
Corners not detected |
DSC_yaw_angular velocity |
DSC |
Triggers engagement of P |
Transmission_Park_position_control |
EMF |
No EGS function when hardware shuts down |
Battery_master_switch_status |
Power |
Spontaneous activation of P |
Peak_reduction_priority_control |
Power |
Incorrect engagement of P/manual engagement of P not possible |
Transmission_selector_button_P_1_operation |
SZL |
Sports programme not possible |
Transmission_selector_button_Sports_operation |
SZL |
Steptronic not possible |
Steptronic_button_operation |
SZL |
EMF fails to release |
Terminal_15_status |
CAS |
Easy open function remains active |
Bonnet_switch_status |
CAS |
Failure to release/hold when vehicle stationary (engine off) |
Key_in_ignition_status |
CAS |
Failure to release/hold when vehicle stationary (engine off) |
Key_in_ignition_status |
CAS |
|
|
|
ACC not functioning/deactivated |
Powertrain_reinforcement |
EGS |
ACC not functioning/deactivated |
Transmission_gear_status |
EGS |
ACC not functioning/deactivated |
Transmission_gear_indication_control |
EGS |
ACC not functioning/deactivated |
Transmission_fault_indication_control |
EGS |
MIL lamp activation, relevant OBD fault |
Transmission_OBD_fault_status |
EGS |
MIL lamp activation, relevant OBD fault |
Transmission_OBD_status |
EGS |
1. Torque control deactivated. 2. ACC DSC deactivated. 3. Consequence: EGS switches to emergency mode |
EGS_alive_torque |
EGS |
EGS deactivated, consequence: Emergency operation |
EGS_specified_torque |
EGS |
EGS deactivated, consequence: Emergency operation |
EGS_torque_checksum |
EGS |
EGS deactivated, consequence: Emergency operation |
EGS_positive_range_specified_torque |
EGS |
Transmission emergency programme |
Pull_away_torque_limitation_status |
EGS |
Torque adjustment not carried out |
EGS_specified_torque_status |
EGS |
No cruise control, no easy start, ability to start at risk |
Transmission_gear_status |
EGS |
DSC lamp activated/DSC inactive/ABS OK |
Transmission_gear_status |
EGS |
DSC and ACC inactive/ABS OK |
Transmission_output_speed |
EGS |
Current status of transmission not identifiable on instrument cluster. Gear indicator arrows flash, position indicator in locator lighting, gear indicator dark |
Transmission_fault_indication_control |
EGS |
All arrows on instrument cluster flash, locator lighting on |
Arrow_display_control |
EGS |
No reversing lights |
Transmission_gear_status |
EGS |
PDC not activated by reverse gear, only by button |
Transmission_gear_status |
EGS |
Abbreviations |
Full expression |
ACC |
Active Cruise Control |
CAS |
Car Access System |
DSC |
Dynamic Stability Control |
EGS |
Electronic transmission control |
SZL |
Steering column switch centre |