Malfunction Indicator Lamp: Description and Operation

Fig. 2 STI connector location. Festiva.:

The Check Engine Indicator lamp will be illuminated when the ignition switch in in the Run position with engine not operating. When the engine is started, the Check Engine lamp should go off. If lamp remains on, a service code has been stored in the EEC-IV self test system memory. After diagnosis and repair, the self test memory may be cleared of stored codes as follows:
1. With ignition switch in the off position, connect a jumper wire between Self Test Input (STI) connector terminal and ground. The STI connector is located in the engine compartment at the rear left hand side, Fig. 2.
2. Position ignition switch in On position, then disconnect and reconnect jumper wire connected between STI connector and ground.
3. Disconnect jumper from STI connector as soon as check engine lamp stops flashing.
4. Disconnect battery ground cable and depress brake pedal for approximately 5 to 10 seconds.
5. Reconnect battery ground cable.