P1594

Tests 21 - 25:

Tests 26 - 27:

SYMPTOM
P-1594 CHARGING SYSTEM VOLTAGE TOO HIGH

WHEN MONITORED
With the ignition key on and the engine speed greater than 0 RPM.

SET CONDITION
When the PCM regulates the generator field and there are no detected field problems but the voltage output does not decrease.

POSSIBLE CAUSES
- Underhood temp within 10 degrees F of battery temp
- Generator field driver circuit short to ground
- Generator shorted
- PCM def (charging system voltage high)
- PCM defective (charging system)