P1610

CHECK ENGINE REQUEST





Fault Symptom.
CHECK ENGINE lamp (MIL) on.

Conditions.
P1610
Short circuit to ground.

P1611
Open circuit.

Diagnostic Help.
The CHECK ENGINE request is made by the transmission control module (TCM) when it wants the CHECK ENGINE lamp (MIL) to be turned on because an emission-related fault has been detected in the automatic transmission.

The status, "YES:/NO:", of the CHECK ENGINE request can be ascertained with the ISAT scan tool.

- Select "ON/OFF".
- Select "CHECK ENGINE REQUEST".

The CHECK ENGINE request can be activated via the TCM by means of the ISAT scan tool.

- Start the engine.
- Select "AUT TRANSMISSION".
- Select "ACTIVATE".
- Select "CHECK ENGINE".

If in proper working order, the CHECK ENGINE lamp (MIL) should light up.

Check The Wiring.
Intermittent faults may occur as a result of temporary short circuits and breaks in the wiring. Jiggle the wiring at several points and in different directions to ascertain whether the wiring harness, including any connectors, is causing the trouble. Observe the multimeter, ISAT scan tool or test lamp while doing this.





Diagnostic Procedure.
1 Check The Wiring

- Check the lead for continuity between:
^ Motronic control module pin 65 and transmission control module pin 5.

Is the lead OK?

YES:
^ Continue with point 2.
NO:
^ Rectify the fault. Continue with point 3.





2 Check the TCM output stage

- Turn the ignition switch to the LOCK position.
- Unplug the Motronic control module's connector.
- Connect the test lamp to the female connector between:
^ pins 65 and 1.
- Connect an ISAT scan tool.
- Turn the ignition switch to the ON position.
- Select "AUT TRANSMISSION".
- Select "ACTIVATE".
- Select "CHECK ENGINE"
At ON, the test lamp should light up for 1 second.

Output stage OK?

YES:
^ Continue with point 3.
NO:
^ Continue fault diagnosis at the Automatic Transmission. Then carry out a final check in accordance with point 3.





3 Final check

- Clear the diagnostic trouble code.
- Implementation of driving cycle:
^ Drive the car at varying engine loads and rpm for 5 minutes.
- Evaluation of driving cycle:
^ Check whether the diagnostic trouble code has recurred.

Has the diagnostic trouble code recurred?

YES:
^ Continue at "Before Replacing a Control Module".
NO:
^ The steps taken to rectify the fault were correct.