Data Link Connector: Description and Operation

Fig. 2 Trouble Code Test Lead Identification:

OPERATION
The trouble code test lead is located under the dash in the Assembly Line Communications Link (ALCL), Fig. 2.

If the test lead is grounded with engine running, the ECM will control system operation as follows: No trouble codes will be set, "Open Loop" timer, start-up enrichment and blended enrichment will be deactivated and a 30° dwell signal will be sent to MC solenoid. Grounding the test lead with the ignition "ON" and engine "OFF" will cause the ECM to display any stored trouble codes.