For a complete wiring diagram Refer to Section 8W.When Monitored:The engine running. The engine speed greater than 1000 RPM.Set Condition:Battery voltage is less than 6 volts for a set period of time. One Trip Fault.Possible CausesRESISTANCE IN THE (A801) BATTERY POSITIVE CIRCUITRESISTANCE IN THE GENERATOR CASE GROUND(K125) GENERATOR FIELD CONTROL CIRCUIT OPEN(K125) GENERATOR FIELD CONTROL CIRCUIT SHORTED TO GROUNDGENERATORPCMAlways 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.Make sure the generator drive belt is in good operating condition.Inspect the fuses in the TIPM. If an open fuse is found, use the wire diagram/schematic as a guide, inspect the wiring and connectors for damage.Start the engine.Allow the engine to reach normal operating temperature.With a scan tool, select View DTCs.It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.Is the DTC Active or Pending at this time?YesGo To 2NoRefer to the INTERMITTENT CONDITION Diagnostic Procedure.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)2. BATTERYMake sure the Battery is in good condition. Using the Midtronics Battery Tester or an equivalent Battery tester, test the Battery before continuing.Does the Battery pass the load test for this specific application?YesReplace the Battery per Service Information.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 33. (A801) B+ CIRCUIT HIGH RESISTANCE

When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.Make sure all wires are clear of the engine's moving parts.Measure the voltage between the (A801) B+ Terminal at the Generator and the Battery + Post.Start the engine.Is the voltage above 0.4 of a volt?YesRepair the excessive resistance in the (A801) B+ circuit between the Generator and Battery.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 44. GENERATOR CASE GROUND HIGH RESISTANCEIgnition on, engine not running.Start the engine.Allow the engine to reach normal operating temperature.Make sure all wires are clear of the engine's moving parts.Measure the voltage between the Generator case and Battery ground post.Is the voltage above 0.1 of a volt?YesRepair excessive resistance in the Generator Ground between the Generator Case and Battery ground side.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 55. 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.Make sure the test light is probing the circuit before actuating the Relay or a DTC may set and not allow the actuation.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 66. (K125) GENERATOR FIELD CONTROL CIRCUIT OPEN

Turn the ignition off.Disconnect the C2 PCM harness connector.Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.Measure the resistance of the (K125) Gen Field Control circuit from the Generator harness connector to the appropriate terminal of the special tool #8815.Is the resistance below 5.0 ohms?YesGo To 7NoRepair the open in the (K125) Gen Field Control circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)7. (K125) GENERATOR FIELD CONTROL CIRCUIT SHORTED TO GROUND

Measure the resistance between ground and the (K125) Gen Field Control circuit in the Generator Field harness connector.Is the resistance below 100 ohms?YesRepair the short to ground in the (K125) Gen Field Control circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 88. 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)