Chrysler Full-Size Trucks 1989-1996 Repair Guide

Reading Diagnostic Trouble Codes


When the CHECK ENGINE light comes on and stays on (after start-up), this indicates that a code (or codes) has been stored in memory. To retrieve this information for purposes of troubleshooting, cycle the ignition switch ON - OFF - ON - OFF - ON within five seconds. The check engine lamp will then flash the DTC(s). Each code, if there is more than one, will be preceded by a four second pause, to distinguish it from the previous code. An example of a DTC would be as follows:

Lamp on for two seconds, then turns off.
Lamp flashes four times, then pauses, then flashes one time.
Lamp pauses four seconds, then flashes four times
Lamp flashes seven times.

The two DTC's displayed, following the two second pause, were 41 and 47. Whenever the malfunction indicator is operated, as many DTC's as are in memory will be displayed. At the end of the sequence, it will flash 55, which indicates it is the end of the stored codes.