Reading and Clearing Diagnostic Trouble Codes

Fig. 2 Data Link Connector Location:

Speed Control Diagnostic Trouble Codes:

CAUTION: When test probing for voltage or continuity at electrical connectors, care must be taken not to damage connector, terminals or seals. If these components are damaged, intermittent or complete system failure may occur.

When trying to verify a speed control system electronic malfunction, connect a scan tool -- if available to the data link connector. The connector is located at left side of the steering column, and at lower edge of the panel.

If a scan tool is not available, use the following procedure:
1. With key inserted in ignition switch, cycle switch to ON position three times. On third cycle, leave switch in ON position.
2. After switch has been cycled three times, observe MALFUNCTION INDICATOR LAMP (check engine) indicator on instrument cluster. If a diagnostic code is present, indicator will flash (blink) in a series which will show which diagnostic code is the problem. Example: A series of three flashes in rapid succession, a slight pause, then four flashes in rapid succession would indicate diagnostic code 34.
3. A speed control malfunction may occur without either diagnostic code being indicated. If no diagnostic code appears or diagnostic code 15 or 34 is observed, refer to the appropriate flow chart.

Refer to Computers and Control Systems/Testing and Inspection/Diagnostic Charts, for further information and useage of the scan tool and a more complete list of Diagnostic Trouble Codes.