Inspection and Verification

Verify the customer concern.

Visually inspect for obvious signs of mechanical or electrical damage.

VISUAL INSPECTION TABLE

Mechanical	Electrical
Throttle body	Central junction box (CJB) fuse 5 (7.5A) Circuitry Stoplamp switch Speed control deactivator switch Powertrain control module (PCM) Speed control switches

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
Verify the speedometer operates correctly without speed control by test driving the vehicle. If the speedometer does not operate correctly, refer to PINPOINT TEST G: THE SPEEDOMETER/ODOMETER IS INOPERATIVE/INACCURATE .
Verify the parking brake warning indicator operates correctly. If the parking brake warning indicator does not operate correctly, refer to INSTRUMENT CLUSTER .
If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
- Check that the program card is correctly installed.
- Check the connections to the vehicle.
- Check the ignition switch position.
If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
Carry out the diagnostic tool data link test. If the diagnostic tool responds with:
- CAN circuits fault; all electronic control units no response/not equipped, refer to PINPOINT TEST O: NO HIGH SPEED CONTROLLER AREA NETWORK (CAN) COMMUNICATION and/or PINPOINT TEST P: NO MEDIUM SPEED CONTROLLER AREA NETWORK (CAN) COMMUNICATION .
- No response/not equipped for PCM, refer to PINPOINT TEST D: THE POWERTRAIN CONTROL MODULE (PCM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOL .
- System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs, and carry out the self-test diagnostics for the PCM.
If the DTCs retrieved are related to the concern, go to the POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
If no DTCs related to the concern are retrieved, GO to SYMPTOM TABLE .

POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX

DTCs	Description	Source	Action
P0500	Vehicle Speed Error	PCM	REFER to AUTOMATIC TRANSMISSION - 6HP26 or AUTOMATIC TRANSMISSION - 4R70E/4R75E .
P0579	Cruise Control Multifunction Input A Circuit Range/Performance	PCM	GO to PINPOINT TEST C .
P0581	Cruise Control Multifunction Circuit High	PCM	GO to PINPOINT TEST C .
P0720	Insufficient Input from Output Shaft Speed (OSS) Sensor	PCM	REFER to AUTOMATIC TRANSMISSION - 6HP26 or PINPOINT TEST E: OUTPUT SHAFT SPEED (OSS) SENSORS .
P0721	Noise Interference on Output Shaft Speed Sensor (OSS) Signal	PCM	REFER to AUTOMATIC TRANSMISSION - 6HP26 or PINPOINT TEST E: OUTPUT SHAFT SPEED (OSS) SENSORS .
P1500	Vehicle Speed Sensor (VSS) Intermittent	PCM	REFER to AUTOMATIC TRANSMISSION - 6HP26 or AUTOMATIC TRANSMISSION - 4R70E/4R75E .
P1501	Vehicle Speed Sensor (VSS) Out of Self-Test Range	PCM	REFER to AUTOMATIC TRANSMISSION - 6HP26 or AUTOMATIC TRANSMISSION - 4R70E/4R75E .
P1572	Brake Pedal Switch Circuit	PCM	GO to PINPOINT TEST B .
P1703	Brake Switch Out of Self-Test Range	PCM	GO to PINPOINT TEST B .
All other DTCs	-	PCM	REFER to INTRODUCTION - GASOLINE article .