To verify PCM power-up during cranking. Lack of power to PCM can cause a no start condition as well as fault code loss. Scan tools often require a minimum system voltage of 9.5 volts to avoid resetting.
Connect the OBDII Scan Tool to the data link connector (DLC) under the dash. Access VPWR PID on OBDII Scan tool and monitor while cranking the engine.
- Low battery voltage.
- Charging system problem.
- Power circuit and ground faults to the PCM.
Note: Battery voltage below 9.5 volts can cause the Sacn tool to reset. If the OBDII Scan Tool resets during a self test or while PID monitoring, it may be necessary to install a battery charger to maintain the correct voltage.
Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent Scan Tool.
- Check Fuel Pulse Width (FUEL PW) While Cranking
- Check RPM Signal While Cranking
- Monitor ICP While Cranking