Reading and Clearing Diagnostic Trouble Codes

Fig. 242 Diagnostic connector pin-out.:

1. Turn the ignition key `OFF'.
2. Connect an analog voltmeter to ground (1) and self-diagnosis (3) set to read 0 to 12 vdc to the diagnostic connector, Fig. 242 located in the engine compartment.

Fig. 243 Diagnostic code table.:

3. Turn the ignition key on and note the indication of the volt meter. If the voltmeter indicates a steady 12 vdc no error codes are present in the ECU memory. If the voltmeter fluctuates, count the number of pulses to determine the error code, Fig. 243.

Note: There may be more than one error code stored in the ECU memory. If so they will be displayed in ascending order with a 2 second pause between each code. Also, the oxygen sensor code is erased when the ignition is turned off. To test for oxygen sensor codes drive the vehicle a significant distance and check for diagnostic codes before turning the ignition off.



4. After the cause of a failure code has been detected and corrected the diagnostic code memory of the ECU should be cleared by disconnecting the vehicle battery for 15 seconds or more. NOTE! Do not disconnect the vehicle battery while the engine is running or while the ignition is on.