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

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

Normal Operation
The charging system indicator is controlled by the instrument cluster based upon data received from the PCM over the high speed controller area network (HS-CAN) communication bus.

If the charging system message is missing or invalid for less than 5 seconds, the charging system indicator remains in the last indication mode (on or off). If the charging system message is missing for more than 5 seconds, the instrument cluster sets DTC U0100 in continuous memory and defaults the charging system warning indicator on. If the charging data received is deemed invalid by the instrument cluster for 5 seconds or longer, the instrument cluster sets DTC U2023 and defaults the charging system warning indicator on.

NOTE: If DTC U0100 is set in the instrument cluster, other observable symptoms may be an inoperative speedometer, tachometer or odometer.

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

M1-M2:

M3-M5: