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