P2504-CHARGING SYSTEM OUTPUT HIGH
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the engine speed greater than 1157 RPM.
- Set Condition:
The PCM compares sensed battery voltage with the Generator Sense circuit voltage. If the Generator Sense circuit voltage if greater than sensed battery voltage, this DTC will set. One Trip Fault. Three good trips to turn off the MIL.
| Possible Causes |
| EXCESSIVE RESISTANCE IN THE B(+) CIRCUIT BETWEEN THE GENERATOR AND THE BATTERY |
| EXCESSIVE RESISTANCE BETWEEN THE GENERATOR CASE AND GROUND |
| (A804) GEN SENSE CIRCUIT SHORTED TO VOLTAGE |
| (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO VOLTAGE |
| GENERATOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - STANDARD PROCEDURE).
Diagnostic Test
1. DTC IS ACTIVENOTE: Inspect the vehicle for aftermarket accessories that may exceed the Generator system output.
NOTE: Inspect the Generator harness connector and the Generator eyelet for corrosion or damage before continuing.
NOTE: Inspect the condition and tension of the Generator belt before continuing.
NOTE: Inspect the battery before continuing.
Ignition on, engine not running.
With a scan tool, select View DTCs. Record DTC and Freeze Frame information
With a scan tool, clear DTCs.
Start the engine and allow it to reach operating temperature.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go to 2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. EXCESSIVE RESISTANCE IN THE B(+) CIRCUIT
WARNING: 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.
NOTE: Make sure all test equipment and cables are clear of any belts, pulleys, or other moving parts.
Monitor the voltage between the generator B(+) output terminal and the battery positive (+) post.
Start the engine.
Is the voltage above 0.4 volts?
Yes
- Repair the battery positive (+) circuit between the generator and battery for high resistance.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go to 3
3. EXCESSIVE RESISTANCE BETWEEN THE GENERATOR CASE AND GROUND
WARNING: 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.
NOTE: Make sure all test equipment and cables are clear of any belts, pulleys, or other moving parts.
Monitor the voltage between the generator case and battery ground (-) post.
Start the engine and allow it to reach operating temperature.
Is the voltage above 0.1 volts?
Yes
- Repair the excessive resistance in the Generator case ground.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go to 4
4. (A804) GEN SENSE CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Generator harness connector.
Disconnect the Powertrain Control Module (PCM) harness connector.
Turn the ignition on.
Measure the voltage of the (A804) Gen Sense circuit.
Is there any voltage present?
Yes
- Repair the (A804) Gen Sense circuit for a short to voltage.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go to 5
5. (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Generator harness connector.
Disconnect the Powertrain Control Module (PCM) harness connector.
Turn the ignition on.
Measure the voltage of the (K20) Gen Field Control circuit.
Is there any voltage present?
Yes
- Repair the (K20) Gen Field Control circuit for a short to voltage.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go to 6
6. GENERATOR
WARNING: 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.
Turn the ignition off.
Connect the Generator harness connector.
Connect the Powertrain Control Module (PCM) harness connector.
NOTE: Make sure all test equipment and cables are clear of any belts, pulleys, or other moving parts.
Measure the voltage between the Generator Eyelet terminal and the (A804) Gen Sense circuit in the Generator harness connector.
Start the engine and allow it to reach operating temperature.
Is the voltage above 0.1 volts?
Yes
- Replace the Generator in accordance with the Service Information.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go to 7
7. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Generator and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
No
- Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).