NGC (Not Equipped with ABS)

P1501-VEHICLE SPEED SENSOR 1/2 CORRELATION - DRIVE WHEELS (Not Equipped with ABS)





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

Ignition on, vehicle moving. Speed control is learned and the speed control is trying to be activated.

- Set Condition:

The PCM recognizes rear wheel speed is greater than the front wheel speed.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. ACTIVE DTC

NOTE: The following items must be checked before continuing.

- Pinion Factor and Tire Size MUST be programmed in the Front Control Module.
- All Bus Communication DTCs MUST be diagnosed.
- All Vehicle Speed DTCs that may be active in the Front Control Module or in the Transmission Control Module MUST be diagnosed.

Ignition on, engine not running.
With a scan tool, read DTCs.

Is the DTC active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking for an Intermittent DTC
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test

2. VISUAL INSPECTION

NOTE: This code can set due to the following conditions.

- Unequal tire circumference between the tires on the vehicle.
- Front or Rear wheels moving while the opposite wheels are not. (i.e., wheels slipping on loose gravel, ice or hard acceleration)

Check tire pressure of all the tires.
Check tire wear on all the tires.
Ask the customer what the road and driving conditions were like when the fault set.

Were any of the above conditions found?

Yes

- Repair as necessary. If the code set during a front OR rear wheel spin condition, no repair is necessary.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test

No

- Go To 3

3. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. PCM Verification Test