Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
D/R input
Pin 42 of the MOTRONIC control module is supplied with information on the current gear position, P-N or R-D-1-2-3, from pin 11 of the automatic transmission's control module.
When any of the gear positions R-D-1-2 or 3 is selected, a supply of about 12 V is applied to pin 42 of the control module, which then attends to idling compensation.
Idling compensation is achieved by the control module opening the IAC valve by about 1.8 grammes per second above normal.
If no signal is received, idling speed will drop below 800 rpm when the DRIVE position is selected and then slowly rise to normal idling speed.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.