Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect the harness connector at the crankshaft position sensor.
- Test for less than 3 Ω between the crankshaft position low reference circuit, terminal B, 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, test for 4.8-5.2 V between the crankshaft position 5 V reference circuit, terminal C and ground.
- If less than the specified range, test the 5 V 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 V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Test for 4.8-5.2 V between the crankshaft position signal circuit terminal A and ground.
- If less than the specified range, test the 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 signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Ignition OFF, connect a 3 A fused jumper wire to the crankshaft position signal circuit terminal A.
- Ignition ON, momentarily touch the other end of the fused jumper wire to a good ground. The crankshaft position active counter should increment.
- If the crankshaft position active counter increments, test or replace the crankshaft position sensor.
- If the crankshaft position active counter does not increment, replace the ECM.