P1790

KICK DOWN SWITCH SHORTED TO GROUND





Fault Symptom.
No downshifting for fast acceleration

Conditions.
Shorting to ground at the same time as the throttle position is less than 70% for at least 2 seconds.

Diagnostic Help.
The condition of the kick-down switch can be checked using an ISAT scan tool. Select "READ ON/OFF". Select KICKDOWN SWITCH". When the accelerator is fully depressed, that is to say in the kick-down position, the ISAT scan tool will show ON. In other accelerator positions it will show OFF.





Procedure.
1. Check the transmission control module's signal input
- Unplug the kick-down switch connector.
- Connect the ISAT scan tool.
- Turn the ignition switch to the ON position.
- Select "READ ON/OFF".
- Select "KICKDOWN SWITCH".

Observe the ISAT scan tool display with

^ connector pin 1 open: "OFF"
^ connector pin 1 connected to a good grounding point: "ON"

Is the ISAT scan tool reading OK?

YES: Proceed to point 3.
NO: Repair or replace the wiring (including connectors) between pin 1 of the kick-down switch connector and pin 8 of the transmission control module. Then continue with point 2.





2. Check the kick-down switch's connection to ground

- Turn the ignition switch to the ON position;
- Connect a test lamp to pins 1 and 2 of the connector. The lamp should light up.

Does the lamp light up?

YES: Adjust or, if necessary, replace the kickdown switch and continue with point 3.
NO: Repair or replace the wiring (including connectors) between pin 2 of the kick-down switch connector and grounding point G4. Then continue with point 3.





3. Final check

Clear the diagnostic trouble code, drive the car on test at varying engine loads and speeds for 5 minutes and obtain readouts of any diagnostic trouble codes that are generated.

Has the diagnostic trouble code recurred?

YES: Continue as described under "Before Changing A Control Module". Before Changing A Control Module
NO: The remedial action taken was correct.