Reading and Clearing Diagnostic Trouble Codes

Fig. 12 Connecting digital code checker to control unit check connector.:

1. Start engine and allow to reach normal operating temperature.
2. Connect digital code checker to check connector, Fig. 12.

Fig. 33 System codes.:

3. If code number is displayed, Fig. 33. refer to ``TESTING PROCEDURES.'' Digital code checker buzzer will sound for approximately 3 seconds after ignition is switched to ``On.''

Fig. 34 Green lamp diagnosis.:

4. Ensure feedback system (Green lamp) Fig. 34. is operating properly, if not check as follows:

Fig. 35 Disconnect throttle sensor.:

a. Disconnect neutral switch connector.
b. Start engine and run at idle.
c. Disconnect throttle sensor connector Fig. 35.. Code 6 should be displayed and green lamp should illuminate.

Fig. 37 Disconnect oxygen sensor.:

d. Increase engine speed to 2500-3000 RPM. Green lamp should flash, within 10 seconds, more than 8 times in 10 seconds.
e. Hold engine speed at 2500 RPM and disconnect O2 sensor connector, Fig. 37. Code 5 should be displayed. Green light should remain illuminated.