P1597 Speed Control Switch Always Low

SYMPTOM
P-1597 SPEED CONTROL SWITCH ALWAYS LOW

WHEN MONITORED
With the ignition key on, and battery voltage greater than 10.4 volts.

SET CONDITION
When switch voltage is less than 0.39 volts for 2 minutes.

POSSIBLE CAUSES
- S/C switch voltage not below 1.0 volt
- S/C signal circuit shorted to ground circuit
- Speed control on/off switch defective
- PCM defective
- Clock spring defective
- S/C resume/accel switch defective
- S/C switch signal circuit short to ground