Engine Engagement/Normal Engine Torque - Short Circuit to Ground

P1782
Engine Engagement / Nominal Engine Torque - Short Circuit to Ground

Function
In order to protect the transmission (Tiptronic), the advance angle is reduced for a short time when a gear shift is carried out at high speeds and high torques.

Diagnosis conditions
- Tiptronic vehicle
- Engine speed > 5080 1/min
- Vehicle speed < 250 km/h

A fault is detected and stored if the wiring from the Tiptronic control unit to the ECM has ground potential for longer than approx. 2.6 seconds.





Wiring diagram





Diagnostic procedure
Check wiring from Tiptronic Control unit to ECM for short circuit to ground.
1. Remove connector at Tiptronic control unit.
2. Remove connector at ECM.
3. Connect ohmmeter between ECM connector pin 42 and ground.
- Display: infinite resistance
- If 0 - 5 ohms is displayed, check wiring harness for trapped locations and abrasions.