For a complete wiring diagram Refer to Section 8W.When Monitored:With the ignition on. Engine RPM greater than 1000 RPM. With no other charging system codes set.Set Condition:Battery voltage is 1 volt greater than desired voltage for more than 10 seconds. Battery voltage greater than 15.75 volts. One Trip Fault. Three good trips to turn off the MIL.Possible Causes(K125) GENERATOR FIELD CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGEGENERATORPCMAlways perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).1. ACTIVE DTCMake sure the Battery is in good condition. Using the Midtronics Battery Tester, test the Battery before continuing.Inspect the vehicle for after market accessories that may exceed the Generator System output.Inspect the fuses in the TIPM. If a fuse is open use the wire diagram/schematic as a guide, inspect the wiring and connectors for damage.Start the engine.Allow the engine to idle.With the scan tool, select View DTCs.Is the DTC Active at this time?YesGo To 2NoRefer to the INTERMITTENT CONDITION Diagnostic Procedure.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)2. GENERATOR OPERATION

Turn the ignition off.Disconnect the Generator Field harness connector.Using a 12-volt test light connected to ground, probe the (K125) Generator Field Control circuit in the Generator Field harness connector.Ignition on, engine not running.With the scan tool, actuate the Gen Field Control circuit.Does the test light illuminate brightly and flash on and off?YesReplace the Generator.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 3 3. (K125) FIELD CIRCUIT SHORTED BATTERY VOLTAGE

Turn the ignition off.Disconnect the C2 PCM harness connector.Ignition on, engine not running.Measure the voltage on the (K125) Gen Field Control circuit at the Generator Field harness connector.Is the voltage above 1.0 volt?YesRepair the short to battery voltage in the (K125) Gen Field Control circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 4 4. PCMBefore continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.Were there any problems found?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoReplace and program the Powertrain Control Module per Service Information.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)