P2504-CHARGING SYSTEM OUTPUT HIGH





For a complete wiring diagram Refer to Section 8W.



Possible Causes
EXCESSIVE RESISTANCE IN THE (A801) BATTERY FEED CIRCUIT
PCM


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1. ACTIVE DTC

NOTE: Inspect the vehicle for aftermarket accessories that may exceed the Generator System output.

NOTE: The battery must be fully charged.

NOTE: The Generator belt tension and condition must be checked before continuing.


Ignition on, engine not running.
With a scan tool, select View DTCs and record the related Freeze Frame data.
With the scan tool erase DTCs.
Start the engine.
Allow the idle to stabilize.
With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes


No

2. (A801) BATTERY POSITIVE CIRCUIT VISUAL INSPECTION

Turn the ignition off.
Inspect the (A801) Battery Positive circuit at Generator Output post for corrosion and looseness.
Inspect the Battery + and – cables for corrosion and looseness.
Inspect the (A0) Battery Positive circuit at the C8 TIPM harness connector for corrosion and looseness.

Were any problems found?

Yes


No

3. EXCESSIVE RESISTANCE IN THE (A209) BATTERY FEED CIRCUIT

CAUTION: 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 and #8815-1 to perform diagnosis.


Disconnect the C1 PCM harness connector.
Perform a voltage drop test on the (A209) Battery Feed circuit from the appropriate terminals of special tool #8815–1 to the C2 TIPM harness.
Using a voltmeter probe the appropriate terminal of special tool #8815-1 with the Negative lead of the voltmeter and back probe the (A209) Battery Feed circuit at the C2 TIPM with the Positive lead of the voltmeter.

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.


Start the engine
Monitor the voltmeter.

Is the voltage above 0.4 of a volt?

Yes


No

4. PCM

NOTE: Before 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?

Yes


No