On-Board Diagnostics

CAUTION: Before entering on-board diagnostics, check charging system for other problems. See INITIAL CHECKS under TROUBLE SHOOTING. DO NOT connect scan tool to vehicle if battery charger is connected, as scan tool damage will result.

NOTE: Self-diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRB-III) scan tool, which will be referred to as scan tool during testing procedures. A generic scan tool should not be used for tests in this article, as it is not capable of performing test functions associated with DTCs that occur. Malfunction Indicator Light (MIL), also known as CHECK ENGINE light (located on instrument panel, just below fuel gauge) may also be used for system diagnostics, but has limited diagnostic capability.

NOTE: PCM cannot diagnose every charging system problem. If fault still exists after performing self-diagnostic procedures, proceed to ON-VEHICLE TESTING.

Faults may be retrieved using Malfunction Indicator Light (MIL) on instrument panel or scan tool. To activate MIL, turn ignition key ON-OFF-ON-OFF-ON within 5 seconds. Count number of times MIL flashes on and off. This represents the DTC. Following is a brief description of DTCs and conditions.

Code 12

Battery feed to PCM has been interrupted within last 50-100 engine starts. PCM monitors this circuit whenever ignition is on.

Code 41

Generator field control fails to switch properly. PCM monitors this circuit whenever ignition is on.

Code 44

Battery temperature sensor voltage is out of range. PCM monitors this circuit whenever ignition is on.

Code 46

Charging system voltage is more than one volt above desired control voltage for more than 20 seconds. PCM monitors this signal whenever engine is running.

Code 47

Charging system voltage is at least one volt less than desired control voltage for more than 20 seconds. No significant change in voltage is detected during active test of generator. PCM monitors this signal whenever engine speed is more than 1500 RPM.