P2504
P2504-CHARGING SYSTEM OUTPUT HIGHP2504-Charging System Output High:
WHEN MONITORED
The engine running. The engine speed greater than 1157 RPM.
SET CONDITION
The PCM compares the B+ feed to the Generator with the Gen Sense circuit. If the Gen Sense voltage input to the PCM is greater than the B+ voltage the DTC will set. One Trip Fault. Three good trips to turn off the MIL.
POSSIBLE CAUSES
- Excessive resistance in the battery positive circuit
- Excessive resistance in the case ground
- GEN sense circuit shorted to voltage
- Generator
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. ACTIVE DTC
NOTE: Inspect the vehicle for aftermarket accessories that may exceed the Generator System output.
Ignition on, engine not running.
NOTE:
- The battery must be fully charged.
- The Generator belt tension and condition must be checked before continuing.
With a scan tool, read DTCs.
With a scan tool, erase DTCs.
Start the engine.
Allow the idle to stabilize.
With the scan tool, read DTCs.
Q: Is the DTC active at this time?
YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. FUSED B+ CIRCUIT HIGH RESISTANCE
NOTE: Inspect the Generator harness connector and the Generator Eyelet for corrosion or damage before continuing.
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.
Ignition on, engine not running.
NOTE: Make sure all wires are clear of the engines moving parts.
Measure the voltage between the Generator B+ Output Terminal and the Battery+ Post.
Start the engine.
Q: Is the voltage above 0.4 of a volt?
YES: Repair the excessive resistance in the battery positive circuit between the Generator and Battery. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 3
3. EXCESSIVE RESISTANCE IN THE CASE 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.
Start the engine.
Warm the engine to operating temperature.
NOTE: Make sure all wires are clear of the engines moving parts.
Measure the voltage between the Generator Case and Battery ground post.
Q: Is the voltage above 0.1 of a volt?
YES: Repair the excessive resistance in the Generator Case Ground. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4
4. (A803/A804) GEN SENSE CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off.
Disconnect the Generator harness connector.
Disconnect the PCM harness connectors.
Turn the ignition on.
Measure the voltage on the (A803/A804) Gen Sense circuit in the Generator Field harness connector.
Q: Does the voltameter indicate voltage present?
YES: Repair the short to battery voltage in the (A803/A804) Gen Sense circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 5
5. INTERNAL HIGH RESISTANCE 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.
Reconnect the Generator harness connector.
Reconnect the PCM Harness connector.
NOTE: Make sure all wires are clear of the engines moving parts.
Measure the voltage between the Generator Eyelet terminal and the Gen Sense circuit in the Generator harness connector.
Start the engine.
Q: Is the voltage above 0.1 of a volt?
YES: Replace the Generator. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Replace the Powertrain Control Module. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test