System Diagnosis: Notes

CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in the GENERAL INFORMATION section before disconnecting battery.

NOTE: Self-diagnostic tests are written specifically for Chrysler's Diagnostic Readout Box (DRB). A generic scan tool may not be capable of performing all necessary test functions. Malfunction indicator (CHECK ENGINE) light can be used, but has limited diagnostic capability.

The self-diagnostic capabilities of this system, if properly used, can simplify testing. Powertrain Control Module (PCM) monitors several different engine control system circuits.

If a problem is sensed with a monitored circuit, Malfunction Indicator Light (MIL) will illuminate and PCM will enter limp-in mode. In limp-in mode, PCM attempts to compensate for particular component failure by substituting information from other sources. This allows vehicle operation until proper repairs are made.

Once trouble codes are known, to determine the questionable circuit, refer to CHARGING SYSTEM TROUBLE CODES table under ENTERING ON-BOARD DIAGNOSTICS.

Perform circuit tests to repair or replace components as required. If problem is repaired or ceases to exist, the PCM will cancel that trouble code after 50 ignition on/off cycles. To clear codes, refer to appropriate ERASING TROUBLE CODES procedure under ENTERING ON-BOARD DIAGNOSTICS .

A specific trouble code results from a particular system failure. Components in that system are not necessarily the reason for that failure. The trouble code does not condemn a specific component, it indicates a circuit malfunction.