P1594

Tests 1 - 3:

Tests 4 - 7:

SYMPTOM
P1594 - CHARGING SYSTEM VOLTAGE TOO HIGH

WHEN MONITORED
With the ignition key ON and the engine speed greater than 380 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
- 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)