Captiva

DTC P0625

The engine control module (ECM) uses the alternator field duty cycle signal circuit to monitor the duty cycle of the alternator and fault indication. The alternator field duty cycle signal circuit connects to the high side of the field winding in the alternator. A pulse width modulated (PWM) high side driver in the voltage regulator turns the field winding ON and OFF. The ECM uses the PWM signal input to determine the generator load on the engine. This allows the ECM to adjust the idle speed to compensate for high electrical loads.

The ECM monitors the state of the alternator field duty cycle signal circuit. When the engine is running, the ECM should detect a duty cycle that varies up to 100 percent. The ECM monitors the PWM signal using a key ON test and a RUN test. During the tests, if the ECM detects an out of range PWM signal, a DTC will set.

The ECM detects a pulse width modulated (PWM) signal less than 5 percent for at least 15 seconds.

DTC P0625 is a C type DTC.

DTC P0625 is a C type DTC.

Schematic Reference

Starting and Charging Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Charging System Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, disconnect the harness connector at the generator.
2. Ignition ON engine OFF, observe the scan tool GEN-F Terminal Signal parameter, while repeatedly probing the alternator field duty cycle circuit with a test lamp connected to battery positive voltage. The parameter should change from 0 percent to above 95 percent.

⇒	If the parameter was not affected by the test lamp, test the GEN-F Terminal Signal circuit terminal 2 for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

3. If the circuit tested normal and the ECM parameter changed from 0 percent to above 95 percent, replace the alternator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.