Retrieving Codes (Without "Scan" Tool)
- Turn ignition on. DO NOT
start engine. TRANS or SERVICE ENGINE SOON light should glow. Locate Assembly Line Data Link (ALDL) connector under dash, on driver's side of vehicle. Turn ignition on with engine not running. Connect jumper wire from terminal "B" (diagnostic terminal) to terminal "A" (ground terminal) of ALDL connector. See Fig 1.NOTE: Connecting terminals "A" and "B" of ALDL connector with engine running will cause fuel injected vehicles to enter field service mode. The TRANS or SERVICE ENGINE SOON light will not flash codes if this is done.
- TRANS or SERVICE ENGINE SOON light should begin flashing codes. Each code will be repeated 3 times. Code 21 is identified by 2 flashes, a short pause followed by one flash; Code 53 is identified by 5 flashes, a short pause followed by 3 flashes. Trouble codes are separated by slightly longer pauses.
- Trouble codes are displayed in numerical order. Each code is displayed 3 times. Codes will continue to repeat as long as ALDL test terminal is grounded.
- If codes are not flashed, or TRANS or SERVICE ENGINE SOON light does not glow, self-diagnostics will not work. See CHART A-1 under DIAGNOSTIC CHARTS. If TRANS or SERVICE LIGHT SOON light glows steadily, see CHART A-2 under DIAGNOSTIC CHARTS. To exit diagnostic mode, turn ignition off, and remove jumper wire from ALDL connector.
NOTE:
Trouble codes will be recorded at various operating times. Some codes require operation of sensor or switch for 5 seconds; others may require operation for 5 minutes or longer at normal operating temperature, road speed and load. Therefore, some codes may not set in a service bay operational mode, but may require road testing vehicle in order to duplicate condition under which code will set.