Data Link Connector: Description and Operation

Assembly Line Diagnostic Link (ALDL) Connector (or DLC).:

RH Rear Of Engine Compartment:

The provisions for communicating with the Engine Control Module (ECM) are the Assembly Line Diagnostic Link (ALDL) connector and the Diagnostic Request terminal in the Duty Check Coupler.

Codes stored in the ECM may be read either through a hand held scanner plugged into the ALDL connector or by counting the flashes of the "CHECK ENGINE" indicator after grounding the diagnostic request terminal in the duty check coupler. Refer to the section on Computers and Control Systems.