Circuit/System Verification
- Engine running, measure and record the voltage at the battery terminals. Verify that the battery voltage is 12.6-15.5 volts.
- If the battery voltage is not within the specified range, refer to Charging System Test .
- Engine running, observe the scan tool ECM Ignition 1 signal parameter. The reading should be between 12.6-15.5 volts.
- If not within the specified range, replace the ECM.