Reading Diagnostic Codes

Below are instructions on how to determine what diagnostic codes are stored in your engines computer. This can be very useful in locating the source of a problem when your check engine light comes on.

Note: This procedure may not be correct for all Celicas. I do not know whether or not this is correct for RWD Celicas and OBD2 (1996-current) Celicas. Please try at your own risk.

1. Check your battery voltage (should be greater than 11 volts), turn off all accessories, put your car in neutral, and make sure your car is at operating temperature.
2. Jump the terminals TE1 and E1of the "Data Link Connector 1" with a jumper wire (a paperclip will do).
3. Turn the ignition to "On" (but dont start the car)
4. Read the trouble code by watching the flashes of the check engine light

Sample Trouble Codes: These codes are for a 6th Gen. Celica...They may, however, be similar and/or carry over to other cars.