P2504
P2504-CHARGING SYSTEM OUTPUT HIGH
For a complete wiring diagram, refer to the Wiring Information.
- When Monitored:
With the engine speed greater than 1157 RPM.
- Set Condition:
The Powertrain Control Module (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.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. PCM Pre-Diagnostic Troubleshooting Procedure
Diagnostic Test
1. ACTIVE DTC
NOTE: 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.
1. Ignition on, engine not running.
2. With a scan tool, select View DTCs. Record DTC and Freeze Frame information.
3. With a scan tool, clear DTCs.
4. Start the engine and allow it to reach operating temperature.
5. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. PCM Intermittent Condition Test.
2. CHECK FOR 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 may result in possible serious or fatal injury.
NOTE: Make sure all Test. equipment and cables are clear of any belts, pulleys, or other moving parts.
1. Monitor the voltage between the generator B+ output terminal and the battery positive (+) post.
2. Start the engine.
Is the voltage above 0.1 volts?
Yes
- Repair the battery positive (+) circuit between the generator and battery for high resistance.
- Perform the PCM VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 3
3. CHECK FOR 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 may result in possible serious or fatal injury.
NOTE: Make sure all Test. equipment and cables are clear of any belts, pulleys, or other moving parts.
1. Monitor the voltage between the generator case and battery ground (-) post.
2. Start the engine and allow it to reach operating temperature.
Is the voltage above 0.1 volt?
Yes
- Repair the excessive resistance in the Generator case ground.
- Perform the PCM VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 4
4. CHECK THE (A804) GENERATOR SENSE CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Generator harness connector.
3. Disconnect the PCM C2 harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (A804) Generator Sense circuit.
Is there any voltage present?
Yes
- Repair the (A804) Generator Sense circuit for a short to voltage.
- Perform the PCM Verification Test. Powertrain Verification Test
No
- Go To 5
5. CHECK THE (K20) GENERATOR FIELD CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Measure the voltage of the (K20) Generator Field Control circuit.
Is there any voltage present?
Yes
- Repair the (K20) Generator Field Control circuit for a short to voltage.
- Perform the PCM Verification Test. Powertrain Verification Test
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 may result in possible serious or fatal injury.
1. Turn the ignition off.
2. Connect the Generator harness connector.
3. Reconnect the PCM C2 harness connector.
NOTE: Make sure all Test. equipment and cables are clear of any belts, pulleys, or other moving parts.
4. Measure the voltage between the Generator Eyelet terminal and the (A804) Generator Sense circuit in the Generator harness connector.
5. Start the engine and allow it to reach operating temperature.
Is the voltage above 0.1 volts?
Yes
- Replace the Generator.
- Perform the PCM Verification Test. Powertrain Verification Test
No
- Go To 7
7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Generator and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test. Powertrain Verification Test.