Circuit/System Testing
WARNING: This page is about a different car, the 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the crankshaft position sensor.
- Ignition OFF, test for less than 1 Ω between the low reference circuit terminal 2 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- Ignition ON, engine OFF, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
- If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Ignition ON, engine OFF, test for 4.8-5.2 V between the signal circuit terminal 3 and ground.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Ignition OFF, connect a fused jumper wire to signal circuit terminal 3.
- Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post/negative battery cable junction block repeatedly. The Crankshaft Position Active Counter and the camshaft position sensor parameter should change.
- If the Crankshaft Position Active Counter and the camshaft position sensor parameter change, test or replace the crankshaft position sensor.
- If the Crankshaft Position Active Counter and the camshaft position sensor parameter does not change, replace the ECM.
- Ignition OFF, inspect the crankshaft position sensor for correct installation.
- If the sensor is loose, inspect the sensor and the O-ring for damage. Replace as necessary.
- Inspect the engine for the following conditions:
- Engine oil for debris
- Crankshaft reluctor wheel for damage
- Timing chain, tensioner, and sprockets for wear or damage
- If debris is found in the engine oil, inspect the internal engine components to determine the cause. Repair or replace any worn or damaged components. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection and Camshaft Cleaning and Inspection .
- If all circuits and components test normal, test or replace the crankshaft position sensor.