System Diagnosis

NOTE: You will not get a code 88 if you are using the "CHECK ENGINE LIGHT" to diagnose the engine control system. There will be a 2-second bulb check, followed by the codes and ending with a code 55. A code 88 will only be set when using Chrysler's DRB: II Tester. Some other "SCAN" testers may also set a code 88 under certain conditions. Check manufacture equipment for specific instructions.

The self-diagnostic capabilities of this system, if properly utilized, can greatly simplify testing. The SMEC has been programmed to monitor several different circuits of the fuel injection system. If a problem is sensed with a monitored circuit often enough to indicate an actual problem, a fault code is stored in the SMEC.

A check engine light comes on or could be activated for display of trouble codes. This light acts as a warning device to inform the operator that a malfunction in the system has occurred and immediate service is required.

When certain malfunctions occur, the SMEC enters the "Limp-In Mode". In this mode, the SMEC attempts to compensate for the failure of the particular component by substituting information from other sources. This will allow the vehicle to be operated until proper repairs can be made.

Once these codes are known, refer to the trouble codes listed in this article to determine the questionable circuit. Then use the wiring diagrams to locate testing points for each circuit. Test circuits and repair or replace as needed. If the problem is repaired or ceases to exist, the logic module cancels the trouble code after 50-100 ignition on/off cycles.