The throttle potentiometer determines the current position of the throttle valve and transfers the signals in the form of a voltage signal to the DME control unit.
Two throttle potentiometers are used for the S62 engine. One potentiometer is mounted on the throttle valve shaft of each cylinder bank. The voltage signals vary dependent on the position of the throttle valve, i.e. for potentiometer 1 (bank 1, cylinders 1 to 4) between 0.5 V and 4.5 V and in the opposite direction for potentiometer 2 (bank 2, cylinders 5 to 8) between 4.5 V and 0.5 V.
When the accelerator pedal is pressed from idle to full load the potentiometer voltage must increase constantly for potentiometer 1 and decrease continuously for potentiometer 2. The ”idle” setting must be indicated when the accelerator pedal is not operated.
Throttle potentiometer adaptation must be deleted after replacing or repairing the throttle potentiometer.
If a fault occurs during operation a corresponding fault code will be stored in the fault code memory of the DME control unit.
For the purposes of checking operation and troubleshooting, the diagnostic program offers the option of initiating a system test (throttle valve test procedure) via the DIS tester/MoDiC and of determining the response of the throttle valve and potentiometer to defined operating conditions.