Test U: The Charging System Warning Indicator Is Never/Always On

PINPOINT TEST U: THE CHARGING SYSTEM WARNING INDICATOR IS NEVER/ALWAYS ON

Normal Operation
The PCM constantly monitors the generator regulator output. When the PCM detects a continuous high or low output signal, or when the ignition switch is ON and the engine is OFF, the PCM sends a message over the communication network to the instrument cluster (IC) to illuminate the charging system warning indicator. When the ignition switch is in the ON position, with the engine running, and the PCM determines that the set point for the regulator has been met, the PCM sends a message to the instrument cluster (IC) to turn off the charging system warning indicator.

This pinpoint test is intended to diagnose the following:
- Charging system concern
- PCM
- Instrument cluster (IC)

U1-U2:

U3-U4: