P1664

SHIFT UP





Fault Symptom.
SHIFT UP lamp on continuously or out of order.

Conditions.
P1864
^ Open circuit.
^ Short circuit to ground/battery positive (B+).

Diagnostic Help.
The SHIFT UP lamp can be activated with the ISAT scan tool.

- Select "ACTIVATE".
- Select "SHIFT UP LAMP".
The command activates the lamp at a frequency of 0.5 Hz for 30 seconds.

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 light bulb

- Check whether the bulb is good.

Is the bulb OK?

YES:
^ Continue with point 2.,
NO:
^ Change the light bulb. Continue with point 3.





2 Check the control module connection

- Unplug the main instrument display panel's connector.
- Connect the test lamp to:
^ Battery positive (B+) and pin 39.
- Connect an ISAT scan tool.
- Turn the ignition switch to the ON position.
- Select "ACTIVATE".
- Select "SHIFT UP LAMP".
The test lamp should flash at a frequency of 0.5 Hz for 30 seconds.

Test lamp flashing?

YES:
^ Continue fault diagnosis in the main instrument display panel.
NO:
^ Check and if necessary repair or replace the lead between pin 39 of the main instrument display panel'S connector and pin 35 of the Motronic control module's connector. Continue 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". Component Tests and General Diagnostics
NO:
^ The steps taken to rectify the fault were correct.