P1501

P1501-VEHICLE SPEED SENSOR 1/2 CORRELATION - DRIVE WHEELS





For a complete wiring diagram refer to Diagrams/Electrical.


- When Monitored:

Ignition on and vehicle moving. Cruise is learned and customer is trying to use the Cruise.

- Set Condition:

The PCM recognizes rear wheel speed is greater than front wheel speed. One trip fault.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.


Diagnostic Test


1. ACTIVE DTC

Ignition on, engine not running.


NOTE: Check for any Bus Communication DTCs. If no Bus Communication DTCs are set, check for active DTCs stored in the Anti-Lock Brake Module. Any Bus Communication DTCs or VSS DTCs in the Anti-Lock Brake Module must be properly diagnosed before continuing.

Start the engine.

Allow the engine to idle.


NOTE: It may be necessary to drive the vehicle for the fault to become Active.

With a scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition

2. VISUAL INSPECTION

NOTE: This code can set due to tire circumference differences and from the front or rear wheels being on a slippery surface while the opposite tires are not.

This code may also set on a hard acceleration on loose gravel or during other off road driving conditions.

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 problems found?

Yes

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

No

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