Test B

PINPOINT TEST B: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING (THE CHARGING SYSTEM VOLTAGE DOES NOT INCREASE)

Test B1:

Test B2-B3:

Test B4-B5:

Normal Operation
With the engine running, the charging system warning indicator should be off. The sense A circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage is used by the voltage regulator to turn off the charging system warning indicator. The I (ignition) circuit 904 (LG/RD) is used to turn on the voltage regulator. This circuit will be 0 volts with the ignition switch in the ON position and the engine not running. Once the engine is started, the I circuit will measure 8-10 volts (C102a connected). The battery positive output (B+) circuit 38 (BK/OG) is the generator output supplied to the battery and electrical system.

Possible Causes
- generator B+ circuit 38 (BK/OG) open or high resistance
- A circuit 35 (OG/LB) open or high resistance
- I circuit 904 (LG/RD) open or shorted to ground
- generator
- powertrain control module (PCM)