2014 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

P2503-CHARGING SYSTEM OUTPUT LOW

For a complete wiring diagram, refer to the Wiring Information.



Possible Causes

LOOSE ACCESSORY DRIVE BELT
EXCESSIVE RESISTANCE IN THE BATTERY POSITIVE CIRCUIT
GENERATOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).


1. ACTIVE DIAGNOSTIC TROUBLE CODE (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.
1. Ignition on, engine not running.
2. With a scan tool, select View DTCs.
3. Read and record the related Freeze Frame data for P2503.
4. With a scan tool, erase DTCs.
5. Start the engine.
6. Allow the idle to stabilize.
7. Ignition on, engine not running.
8. Using the scan tool, read the active DTCs.


Is the DTC Active at this time?

Yes


No


2. FUSED B+ CIRCUIT HIGH RESISTANCE

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. Ignition on, engine not running.
2. Measure the voltage between the Generator B+ Output Terminal and the Battery + Post.
3. Start the engine.


Is the voltage above 0.4 Volt?

Yes


No


3. GENERATOR OPERATION
1. Turn the ignition off.
2. Disconnect the Generator Field harness connector.
3. Using a 12-Volt test light connected to ground, probe (K20) Generator Field Control circuit in the Generator Field harness connector.


NOTE: The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate.
4. Ignition on, engine not running.
5. With a scan tool, actuate the Generator Field Driver.

NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery.


Does the test light illuminate accordingly?

Yes


No


4. 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. Verify that there is good pin to terminal contact in the Generator and the Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.


Were there any problems found?

Yes


No