Circuit/System Testing
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, open the hood to disable the Auto-Stop function.
- Ignition ON, verify the scan tool hood position parameter displays Open.
- If the hood position does not display Open, refer to DTC P254F .
- Ignition OFF, remove the fuse that supplies B+ to terminal X2-56 of the ECM.
- Disconnect the harness connector X1 at the Starter Generator Control Module (SGCM).
- Disconnect the harness connector at the crankshaft position (CKP) sensor.
- Test for less than 10 Ω between the low reference circuit terminal 1 and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuits/connections test normal, replace the ECM.
- Install the fuse that supplies B+ to terminal X2-56 of the ECM.
- Ignition ON, test for greater than 4.8 V between the 5-volt reference circuit terminal 3 and the low reference circuit terminal 1.
- If less than the specified value, test the 5-volt reference circuit for an open/high resistance. If the circuits/connections test normal, replace the ECM.
- Test for 4.8-5.2 V between the signal circuit terminal 2 and ground.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If circuit/connections test normal, replace the ECM.
- If greater than the specified range, test the signal circuit for a short to voltage. If circuit/connections test normal, replace the ECM.
- Ignition OFF, connect the harness connector X1 at the SGCM.
- Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 2 and ground.
- If less than the specified range, test the signal circuit for a short to ground. If circuit/connections test normal, replace the SGCM.
- If greater than the specified range, test the signal circuit for a short to voltage. If circuit/connections test normal, replace the SGCM.
- If all circuits/connections test normal, test or replace the CKP sensor.
NOTE:
The CKP sensor signal and low reference circuits are shared with the SGCM. A circuit condition between the splice and SGCM can set a DTC.