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
- Speed control on/off switch defective
- Speed control resume/accel switch defective
- S/C signal circuit shorted to ground circuit
- Powertrain control module defective
- Clock spring defective
- S/C switch signal circuit shorted to ground