Diagnostic Procedures
- If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
- Verify Generator Drive Cycle
Check generator drive belt condition and tension. Start engine and verify generator is turning. If everything is okay, go to next step. If everything is not okay, repair or replace parts as necessary. After repair, go to step 11.
- Verify Charging System Is EEC Controlled
Turn ignition off. Disconnect battery cables at battery. Disconnect generator 3-pin harness connector and measure resistance between BATT-SENSE and GEN-COM terminals at generator. If resistance reading is between 950 and 1050 ohms, go to next step. If resistance reading is not as specified, Replace generator/regulator assembly. After repair, go to step 11.
- Check Battery-Sense Voltage At Battery
Reconnect battery cables. Measure voltage at generator/regulator 3-pin harness connector between ground and BATT-SENSE terminal (Black/Yellow wire). If voltage reading of BATT-SENSE circuit is within 0.5 volt of battery voltage, go to next step. If voltage reading is not as specified, Repair Black/Yellow wire between generator/regulator 3-pin harness connector and positive battery terminal. See WIRING DIAGRAMS
article. After repair, go to step 11.
- Check Generator Failure Mode
Turn off all electrical loads. Access GFS PID. Start engine and increase engine speed to 2000 RPM. Perform wiggle test. If no failure is indicated, go to next step. If a failure is indicated, repair as necessary. After repair, go to step 11.
- Check GEN-MON & GEN-COM Circuit For Short To Power
Turn ignition off. Disconnect generator 3-pin harness connector. See Fig 1. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Turn ignition on, engine off. Measure voltage between ground and breakout box terminal No. 72 (GEN-COM). Measure voltage between ground and breakout box terminal No. 59 (GEN-MON). Turn ignition off. If each voltage reading is more than 0.5 volt, repair short circuit. See WIRING DIAGRAMS
article. After repair, go to step 11.
Courtesy of FORD MOTOR CO.
- Check GEN-MON & GEN-COM Circuit For Short To Ground
Measure resistance between ground and breakout box terminal No. 72 (GEN-COM). Measure resistance between ground and breakout box terminal No. 59 (GEN-MON). If each resistance reading is not more than 10,000 ohms, go to next step. If each resistance reading is more than 10,000 ohms, repair open circuit. After repair, go to step 11.
- Check GEN-MON & GEN-COM Circuit For Open
Measure resistance of GEN-COM circuit between breakout box terminal No. 72 and generator/regulator 3-pin harness connector (Brown/White wire). See Fig 1. Measure resistance of GEN-MON circuit between breakout box terminal No. 59 and generator/regulator 3-pin harness connector (Gray/Orange). If each resistance reading is less than 5 ohms, go to next step. If each resistance reading is more than 5 ohms, repair open circuit. After repair, go to step 11.
- Check Generator Monitor Signal
Start engine. Access GF PID. If duty cycle is 6-98 percent, go to next step. If duty cycle is not as specified, replace generator/regulator. After repair, go to step 11.
- Check Generator Communicator Signal
Start engine. Access GENFDC PID. Toggle load on and off (headlights). If duty cycle is 0-99 percent, go to next step. If duty cycle is not 0-99 percent, replace generator/regulator. After repair, go to next step.
- Verify Trouble Shooting Of DTCs Completed
Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are present, trouble shooting is complete.