Sierra 2500 Denali 2WD V8-6.0L (2011)
Note: You must perform the Circuit/System Verification first.
1. Disconnect the ECM harness connector X1.
2. Measure for 1,300-1,500 ohms at 25°C (77°F) between the VSS high signal circuit terminal 54 and the VSS low signal circuit terminal 34.
‹› If the value is greater than 1,500 ohms test the VSS high signal circuit and the VSS low signal circuit for an open/high resistance. If the
circuits/connections test normal, replace the vehicle speed sensor.
‹› If the value is less than 1,300 ohms test the VSS high signal and the VSS low signal circuits for a shorted together condition. If the
circuits/connections test normal, replace the vehicle speed sensor.
3. Measure for more than 10 ohms of resistance between the VSS high signal circuit terminal 54 and ground.
‹› If the value is less than the specified range, repair the short to ground.
4. Measure for more than 10 ohms of resistance between the VSS low signal circuit terminal 34 and ground.
‹› If the value is less than the specified range, repair the short to ground.
5. Reconnect the ECM connector. Disconnect the VSS connector.
6. Ignition OFF, test for less than 5 ohms between the low reference circuit at the VSS harness connector terminal B and ground.
‹› If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
7. Ignition ON, test for less than 6 V between the signal circuit at the VSS harness connector terminal A and ground.
‹› If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Testing and Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests
and Procedures) after completing the repair.
*
Vehicle Speed Sensor Replacement (See: Service and Repair)
*
Control Module References (See: Testing and Inspection/Programming and Relearning/Control Module References)for ECM replacement, setup
and programming.
