Circuit/System Testing
WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
- Measure the voltage at the battery terminals and compare it with the Ignition 1 Signal parameter on the scan tool. Verify that battery and Ignition 1 signal readings do not differ more than 1.0 volt.
- If greater than 1.0 volt, test the Ignition 1 and ground circuits of the TCM for high resistance. If the circuits test normal replace the TCM.
- Go to Charging System Test .