Test C: DTC P0579 Or DTC P0581 - Speed Control Switch Circuit Failure

PINPOINT TEST C: DTC P0579 OR DTC P0581 - SPEED CONTROL SWITCH CIRCUIT FAILURE

Normal Operation
The PCM sends a signal through circuit 248 (TN/OG) to the speed control switches. The return signal is sent through circuit 133 (BK). Both circuits pass through the clockspring.

DTC P0579 (Speed Control Switch Circuit Failure) - sets when the speed control switch circuits are open, shorted to voltage or shorted to ground.

DTC P0581 (Speed Control Switch Circuit Failure) - sets when the speed control switch circuits are shorted to voltage or open.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Clockspring
- Speed control switch
- PCM

C1-C2:

C2-C4:

C4-C6:

C6-C8:

C8-C10: