9A - Check VPWR During Cranking

9a. Check VPWR During Cranking





Purpose:
To verify PCM power-up during cranking. Lack of power to PCM can cause a no-start condition as well as fault code loss. The NGS Tester requires a minimum system voltage of 9.5 volts to avoid resetting.

Recommended Procedure:
Install NGS Tester. Access VPWR PID on NGS Tester and monitor while cranking the engine.

Possible Causes:
- Low battery voltage
- Charging system problem
- Power circuit and ground faults to the PCM

Refer to Pinpoint Test A to diagnose a voltage concern. A - Vehicle Battery

NOTE: Battery voltage below 9.5 volts can cause the NGS Tester to reset. If the NGS Tester resets during a self test or while PID monitoring, it may be necessary to install a battery charger to maintain the correct voltage.

Tools Required:
New Generation Star (NGS) Tester OO7-00500 or equivalent