Circuit/System Testing
- Measure the voltage at the battery terminals and compare it with the Ignition 1 signal parameter in the ECM data list. Verify that battery and Ignition 1 signal readings do not differ more than 0.8 volts.
- If more than 0.8 volts, test the Ignition 1 and ground circuits of the ECM for an open, high resistance or replace the ECM.
- Go to Charging System Test .