GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Data Link Communications System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Connect the scan tool to the Data Link Connector (DLC).
  2. Turn the ignition switch to the RUN position.
  3. Attempt to establish communication with the Class 2 serial data line.
    • The scan tool turns ON.
    • The scan tool communicates with the Class 2 serial data line.

Scan Tool Does Not Communicate with Class 2 Data Line

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.