RETRIEVING DTCS
DTCs are retrieved using a Tech 1 or other OBD-II compatible scan tool connected to 16-pin Data Link Connector (DLC). (Scheme 13) DLC is located below instrument panel, accessible from driver's side. Follow scan tool manufacturer's instructions when retrieving DTCs.
Scheme 13
FREEZE FRAME DATA
Engine operating conditions can be captured and stored in PCM memory whenever MIL is illuminated. Data captured is called FREEZE FRAME data. Freeze frame data is similar to a single record of operating conditions. Whenever MIL is illuminated, corresponding record of operating conditions is recorded to freeze frame buffer.
Freeze frame data can only be overwritten with data associated with a misfire or fuel trim malfunction. Misfire data takes priority over all other data because of its related part-damaging effects (oxygen sensors, catalytic converters, etc.). Freeze frame data will not be erased unless associated DTC is cleared from PCM memory.
Note. MIL will flash once every second if PCM detects a condition or misfire which could cause damage to catalytic converter.
MALFUNCTION INDICATOR LIGHT (MIL) CHECK
- Turn ignition on. If MIL illuminates, go to next step. If MIL does not illuminate, go to CIRCUIT TEST A-1: MALFUNCTION INDICATOR LIGHT (MIL) INOPERATIVE in appropriate SELF-DIAGNOSTICS article. Repair as necessary.
- Start engine. If MIL turns off, system is okay. If driveability problems are present, go to «TROUBLE SHOOTING - NO CODES»(ref-91186) article. If MIL remains illuminated, check for DTCs. See «RETRIEVING DTCS»(ref-91182-S33769316922001030500000) . If no DTC is stored in PCM memory and MIL is illuminated, go to CIRCUIT TEST A-2: MALFUNCTION INDICATOR LIGHT (MIL) REMAINS ILLUMINATED in appropriate SELF-DIAGNOSTICS article. Repair as necessary.
SUMMARY
If no DTCs are present, and driveability symptoms exist, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., rough idle, no start, etc.).