Drive position
Drive position |
Information on the current gear position, P-N or R-D-3-2-1, is sent from the transmission control module pin 11 to the engine control module.
Motronic receives the signal on pin 47 and Trionic on pin 14.
When shifting from N to any of the gear positions R, D, 3, 2 or 1, the transmission control module put B+ on pin 11. Otherwise the voltage is 0 V. This is to inform the engine control module that a gear position (forward or reverse) has been selected. The engine control module then ensures that the idling speed is compensated for the change in load.
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Idle speed compensation is achieved by the engine control module opening the idle air control valve more than normal, whereby retaining a constant idling speed. If the signal is absent, the idling speed will drop below 900 rpm when DRIVE is selected and then slowly increase to normal idling speed.