Two switches are fitted on the brake pedal which supply the following signals:
The DDE control module evaluates the signals for the purpose of registering brake operation.
The brake light switch connects to earth, the brake light test switch connects to positive. Both signals are checked for plausibility.
The following table shows how the signals behave:
|
Brake light switch is |
Brake-light test switch is |
Brake pedal operated |
Open |
Closed |
Brake pedal not operated |
Closed |
Open |
Troubleshooting
If the signals are implausible, the faults are saved in the DDE control module. Cruise control is deactivated as a result.
A switch is fitted on the clutch pedal for the purpose of registering clutch operation on vehicles with manual transmission.
The clutch switch switches to ground. The plausibility of the signal is checked together with cruise control.
The following table shows how the signal behaves:
|
Clutch switch is |
Clutch operated |
Open |
Clutch not operated |
Closed |
Troubleshooting
If the signal is implausible, the faults are saved in the DDE control module. Cruise control is deactivated as a result.
The position of the accelerator pedal is reported to the DDE control module via analog voltage signals. The signals are generated by two pedal-position sensors in the accelerator pedal module.
The pedal-position sensors take their 5 V power supply and ground connection from the DDE control module. Depending on the operating angle, the pedal-position sensors return various voltages to the DDE control module. The DDE control module converts the voltage signals into the accelerator pedal setting.
The signal of pedal-position sensor 2 always has half the signal voltage of pedal-position sensor 1.
The idle, full throttle and kickdown positions are detected by way of voltages of the pedal-position sensors.
Troubleshooting
The pedal-position sensors are monitored for short circuit and interrupt as well as for plausibility in relation to one another.