P0500 NO VEHICLE SPEED SENSOR SIGNAL
When Monitored and Set Condition:
When Monitored: While the engine is running.
Set Condition: The ECM indicates signals of motion; however, the VSS does not.
POSSIBLE CAUSES
- VEHICLE SPEED (G7) SIGNAL CIRCUIT SHORTED TO VOLTAGE
- VEHICLE SPEED (G7) SIGNAL CIRCUIT OPEN BETWEEN CAB AND ECM
- VEHICLE SPEED (G7) SIGNAL CIRCUIT SHORTED TO GROUND
- ECM
DIAGNOSTIC PROCEDURE
-
Turn the ignition off. Disconnect the ECM harness connectors. Disconnect the ABS/RWAL Module harness connector. Ignition on, engine not running. Measure the voltage of the Vehicle Speed (G7) signal circuit in the ABS/RWAL or ECM harness connector. Is the voltage above 4.9 volts?
Yes --> Repair the short to voltage in the Vehicle Speed (G7) Signal circuit between the CAB and ECM. Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL).
No --> Go To 2 -
Turn the ignition off. Measure the resistance of the Vehicle Speed (G7) signal circuit between the ECM harness connector and the ABS/RWAL harness connector. Is the resistance above 5.0 ohms?
Yes --> Repair the open in the Vehicle Speed (G7) signal circuit between the CAB and ECM. Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL).
No --> Go To 3 -
Measure the resistance between ground and the Vehicle Speed (G7) signal circuit at the ECM harness connector. Is the resistance below 100 ohms?
Yes --> Repair the short to ground in the Vehicle Speed (G7) signal circuit between the CAB and ECM. Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL).
No --> Go To 4
NOTE: Before continuing, check the ECM 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. If there are no possible causes remaining, view repair. Repair Replace and program the ECM per Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 2 (DIESEL).