Cruze

DTC P0625

The engine control module (ECM) uses the generator field duty cycle signal circuit, or F-terminal circuit, to monitor the duty cycle of the generator. The generator field duty cycle signal circuit connects to high side of the field windings in the generator. A pulse width modulated (PWM) high side driver in the voltage regulator turns the field windings 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 status of the generator field duty cycle signal circuit. When the key is in the RUN position and the engine is OFF, the ECM should detect a duty cycle near 0 percent. When the engine is running, the duty cycle should be between 5–99 percent.

The ECM detects that the field duty cycle signal is less than 5 percent for 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 ON, engine OFF, observe the scan tool GEN-F Terminal Signal parameter. The reading should be less than 5%.
2. Engine running, observe the scan tool GEN-F Terminal Signal parameter. The reading should be greater than 5%.

1. Verify that a test lamp illuminates between the G13 generator B+ output circuit terminal 1 X1 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

2. Ignition OFF, disconnect the X2 harness connector at the G13 generator.
3. Ignition ON, verify the scan tool GEN-F Terminal Signal is less than 5%.

⇒	If greater than the specified range, test the signal circuit terminal 2 X2 for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 2 X2 and B+. Verify the scan tool GEN-F Terminal Signal is greater than 95%.

⇒	If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

5. If all circuits test normal, test or replace the G13 generator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.