Reading and Clearing Diagnostic Trouble Codes

Fig. 11 Connecting digital code checker to control unit check connector.:

1. Start engine and allow to reach normal operating temperature. Engine speed should be below 4000 RPM while warming up.
2. Connect digital code checker to check connector, Fig. 11.
3. Start engine and wait for 3 minutes.
4. If code number is displayed, refer to ``Testing Procedures'' and note the following:
a. The green light on the checker indicates operation of the O2 sensor, indicating whether or not the sensor signal is being fed back to the EGI control unit. When light is off, a lean air/fuel mixture is indicated and when light is illuminated a rich air/fuel mixture is indicated.
b. If there is more than one fault, the indication will be for the lowest code number first.
c. If the ignition switch is switched off after a malfunction has occurred, the malfunction indicator will not be displayed on the checker.
d. The control unit has a built in fail-safe mechanism. If a fault occurs during driving, the control unit will substitute values on its own initiative as shown.