Accessing and Reading Diagnostic Trouble Codes

On-Board Diagnostics Diagram - Part 1 Of 2:

On-Board Diagnostics Diagram - Part 2 Of 2:

Instrument Panel Cluster:

OPERATING ON-BOARD DIAGNOSTIC SYSTEM
Basic Operation
To enter diagnostic mode, proceed as follows:

1. Turn ignition "ON."
2. Depress the "OFF" and "WARMER" buttons on the Climate Control Center (CCC) simultaneously and hold until the segment check appears on the Instrument Panel Control (IPC).
3. To proceed to the desired level, press and release the indicated button.
4. Press "OFF" to return to the next selection in the previous level.

SEGMENT CHECK
The purpose of illuminating the IPC is to check that all segments of the LED displays are working. The turn signal indicators DO NOT light during this check. If any of the segments are inoperative, the affected display panel will need to be diagnosed.

TROUBLE CODE DISPLAY
After the segment check, any trouble code stored in computer memory will be displayed. Codes may be stored for the PCM, IPC, ACP, or SIR systems.

Each trouble code consists of the system abbreviation: (P: Engine, PCM), (I: IPC), (A: ACP), (R: SIR), (T: TCS), (S: RSS), a three digit code identifier, and the letter C or H. All codes for each system are displayed together, in the order of their three digit number (lowest first). The final digit of the code, a "C" or "H" is used to indicate whether the code is Current or History. A "C" means the fault was still present the last time the diagnostic test was run, while "H" means the failure was not present the last time the code was tested for.

If no codes are present for a system, a "NO X CODE" message (with "X" being the system i.e. E, I, A, R, T or S) will be displayed. If the communication line to a component is not operating, a "NO X DATA" message will be displayed, indicating that the IPC could not communicate with that system.

At any time during the display of trouble codes, if the "AUTO" button on the IPC is depressed the system will exit "Service Mode" and go back to normal vehicle operation.

EXITING DIAGNOSTIC MODE
To get out of the diagnostic mode, depress the "AUTO" or "DEFOG" button, or turn the ignition switch "OFF." Pressing the "RESET" button on the DIC will also exit diagnostics. Trouble codes are not erased when this is done.