Accessing and Reading Diagnostic Trouble Codes

Fig. 5 Control Module Connector.:

Fig. 6 Error Diagnostic Trouble Code Format.:

The CCR diagnostic systems may be actuated by either of two methods. Grounding the diagnostic enable circuit at pin C of the Data Link Connector (DLC) or by using the control module wiring harness connector, Fig. 5. To read diagnostic trouble codes using the control module connector ground terminal F2 of the connector.

Both driver select switch LEDs will blink in unison to transmit blink code diagnostics. Error diagnostic trouble codes can be read by counting the number of flashes of the LED's. The error diagnostic trouble code display will start after pin D2 or F2 has been grounded for three seconds before beginning the blink diagnostic trouble code sequence. The sequence starts with a three second LED off period. Then diagnostic trouble code 12 is displayed three times to mark the beginning of the sequence. Next, each stored code is blinked out in ascending order. Each diagnostic trouble code is displayed three times before proceeding to the next diagnostic trouble code. If pins D2 and D16 remain connected or terminal F2 remains grounded, the entire diagnostic trouble code sequence will repeat beginning with diagnostic trouble code 12 flashing three times. Refer to Fig. 6 for an example of an diagnostic trouble code format.