P0501-VEHICLE SPEED SENSOR PLAUSIBILITY
For a complete wiring diagram Refer to Section 8W
- When Monitored:
Engine temperature above 10.0°C. Battery voltage above 11.0 volts Transmission in drive gear. Brake Switch off (brakes not applied). Varying engine speed and load (indicating vehicle motion).
- Set Condition:
The vehicle speed message to the ECM indicates 0 mph when the ECM monitoring condition indicate that vehicle speed should be above 0 mph.
| Possible Causes |
| INTERMITTENT CONDITION |
| CHECK FOR RELATED CONTROLLER ANTILOCK BRAKES DTCS |
| CHECK FOR RELATED TRANSMISSION CONTROL MODULE DTCS |
| ENGINE CONTROL MODULE |
Diagnostic Test
1. CHECK FOR ACTIVE DTCNOTE: If the ECM displays multiple CAN Bus related DTC's, check the CAN Bus circuits at the ECM harness connector for proper connection before continuing with this test.
NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the scan tool, erase ECM DTCs.
Test drive the vehicle.
With the scan tool, read the ECM DTC's.
Does the scan tool display this DTC?
Yes
- Go To2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. CHECK FOR RELATED CAB DTCS
Turn the ignition on.
With the scan tool, check for Controller Antilock Brakes DTCs.
NOTE: The ECM Receives vehicle speed messages via CAB Bus from the ABS module. An interruption on the CAN Bus can cause this fault to set.
Are any related CAB DTCs present?
Yes
- Refer to symptom list for problems related to CAB DTCs before continuing.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To3
3. CHECK FOR RELATED TCM DTCS
NOTE: The TCM Receives vehicle speed messages via CAB Bus from the ABS module. An interruption on the CAN Bus can cause this fault to set.
Turn the ignition on.
With the scan tool, check the TCM for DTCs.
Are any ABS CAN Bus Message or Vehicle Speed related TCM DTCs present?
Yes
- Replace the CAB in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Replace and program the Engine Control Module in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).