Test D: The Charging System Warning Indicator Is On With the Engine Running and the Battery Increases Voltage

PINPOINT TEST D: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING AND THE BATTERY INCREASES VOLTAGE

D1:

D1-D3:

D3-D5:

Normal Operation
With the engine running, the charging system warning indicator is off. The sense A circuit SDC02 (RD) to the generator field coil measures 13-15 volts. The S (stator) circuit (internal to the generator on all 4.6L vehicles, but an external circuit VDC42 [GN] on 4.0L vehicles) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage feedback signal (typically half the battery voltage) is used by the voltage regulator to provide a signal to the PCM, which in turn provides a signal over the controller area network (CAN) communication link to the instrument cluster (IC) to turn off the charging system warning indicator. The I (ignition) circuit CDC09 (YE) is used to turn on the voltage regulator. This circuit measures 6-8 volts (C102a [4.0L], C1104a [4.6L] connected) with the key in the ON position and the engine not running. Once the engine is started, the I circuit measures 8-10 volts (C102a [4.0L], C1104a [4.6L] connected). The positive battery output (B+) circuit SDC02 (RD) is the generator output supplied to the battery and electrical system.

This pinpoint test is intended to diagnose the following:
- IC
- Generator
- PCM
- Circuitry