Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
P0335
- Disconnect the CKP sensor.
- Test for less than 1 ohm between low reference circuit terminal 2 on the ECM side of the connector 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.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 on the ECM side of the connector and ground.
- If less than the specified range, test the 5-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 1 on the ECM side of the connector and ground.
- If less than the specified range, test the affected signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the affected signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Ignition OFF, connect a 3A fused jumper wire to the CKP signal circuit terminal 1 on the ECM side of the connector.
- Ignition ON, momentarily touch the end of the fused jumper wire to ground. The crank signal present and the engine RPM parameters on the scan tool should change.
- If the crank signal present and the engine RPM does not change, replace the ECM.
- Ignition OFF, inspect the wiring harness for any damage, opens, or shorts.
- If the circuits test normal replace the CKP sensor.