P1594

Tests 1 - 3:

Tests 4 - 8:

SYMPTOM
P1594 - 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
- Battery temperature sensor
- Generator field driver circuit shorted to ground
- Generator field shorted to ground
- PCM (battery temperature)
- Powertrain Control Module (battery voltage)
- Powertrain Control Module (generator resistance)