Reading and Clearing Diagnostic Trouble Codes

Entering Self-Diagnostic Mode
1. Turn ignition switch ON.
2. Simultaneously depress the OFF and WARMER buttons on the climate control panel and hold buttons until all display panel segments are illuminated which indicates the beginning of the diagnostic readout. The purpose of illuminating the two display panels is to ensure that all segments are working. If any segments are are inoperative, the affected display panel must be replaced.
3. After the display segment check is completed, any stored trouble code will be displayed on the data center. These two-digit codes will be displayed with a prefix of either E or F to designate which computer sensed the malfunction. If a trouble code is displayed, or if the self-diagnostics system cannot be accessed, a defect has been sensed in the vehicle's electronic control system. To diagnose these malfunctions, refer to COMPUTERS AND CONTROL SYSTEMS.
4. After all codes are displayed or if no trouble codes are stored, the code .7.0 will appear on the display.

Code .7.0 is a decision point. When this code is displayed, the diagnostic feature relevant to the current malfunction can be selected. The two diagnostic modes relevant to cruise control diagnosis, ECM switch tests and ECM output cycling, are detailed below.

Clearing Trouble Codes
The trouble codes stored in the system memory can be cleared to aid in diagnosing intermittent conditions. To clear codes, proceed as follows:
1. Enter diagnostic mode as outlined.
2. To clear engine control module (ECM) codes, simultaneously depress the OFF and HI buttons on the climate control panel and hold the buttons until the code E.0.0 is displayed.
3. To clear body control module (BCM) codes, simultaneously depress the OFF and LO buttons on the climate control panel and hold until the code F.0.0 is displayed.
4. After E.0.0 and F.0.0 are displayed, the code .7.0 will be displayed. With this code displayed, turn the ignition OFF and leave ignition OFF for at least 10 seconds before re-entering the diagnostic mode.

Exiting Self-Diagnostic Mode
To exit the self-diagnostic mode, depress the AUTO button on the climate control panel or turn the ignition OFF for at least 10 seconds.