Displaying and Reading Trouble Codes

DIAGNOSTIC TROUBLE CODES

Diagnostic Trouble codes, when set, indicate that the DERM has detected a malfunction in a particular circuit. The DERM is programmed with routines or checks that it follows only under prescribed conditions (called Test Conditions) See "Diagnostic Description" for more details. When these conditions exist, the DERM checks certain circuits for a malfunction. These checks are called failure conditions. When the failure conditions are true, a diagnostic trouble code is set. Diagnostic trouble codes alert the driver through the 'INFLATABLE RESTRAINT' indicator and 'SERVICE SUPPLEMENTAL INFLATABLE RESTRAINT' message displayed on DIC. The DERM also saves data when Code RO51 is set.


Current Code:

When the DERM determines that the test conditions and failure conditions for a particular code are true, it sets that code as 'Current'. Most codes remain current at least until the 'Failure Conditions' are no longer met. A few codes remain current until the next ignition cycle. Code RO51 (Frontal Crash Detected) will remain current until it is cleared using a scan tool. Specific details are given on the trouble tree for each code.


History Code:

After a code has been set, the DERM continues to monitor for 'Failure Conditions'. When 'Failure Conditions' no longer exist, the code is changed to history. Some codes require an ignition cycle to change from current to history. Codes R083 and RO84 only set as history codes and therefore have no conditions to change from current to history. All history codes can be cleared by using on - board diagnostics.

TROUBLE CODE DIAGNOSIS

Use diagnostic charts, wiring diagrams, and descriptive text to direct you in performing specific tests to locate and repair the problem. The diagnostic chart is a step by step procedure to determine the circuit or component that is the source of the problem. The wiring diagrams and text describing the system, test conditions, failure conditions, and actions taken when a code is set.


DIAGNOSTIC CODE DISPLAY

Complete information regarding operation of the ON-BOARD DIAGNOSTIC SYSTEM. Briefly, code display works as follows:

To display the diagnostic codes, the ignition must be in the ON position. The OFF and WARMER buttons of the Electronic Climate Control Panel (ECCP) are depressed until all the segments of the display are ON. The Driver Information Center (DIC) will display the diagnostic codes in the following manner:

1. All codes set. Each code will be displayed along with it's status, current or history.

2. The order of fault display will be PCM, IPC, ACP, SIR, TCS and RTD.

3. Depressing the LO button will bypass code display.