Symptoms - Data Link Communications

Symptoms - Data Link Communications

Important: The following steps must be completed before using the symptom tables:


1. Perform the Diagnostic System Check for the subsystem exhibiting the symptoms. The subsystem diagnostic system check will identify where to begin diagnosis of the data link communication system.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to Data Link Communications Description and Operation Data Link Communications Description and Operation.

Visual/Physical Inspection

* Inspect for aftermarket devices that could affect the operation of the serial data communications systems. Refer to Checking Aftermarket Accessories Checking Aftermarket Accessories in Wiring Systems.
* Inspect the easily accessible systems or visible system components for obvious damage or conditions that could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

* Scan Tool Does Not Power Up Scan Tool Does Not Power Up
* Scan Tool Does Not Communicate with Class 2 Device (LG5 Diesel) Scan Tool Does Not Communicate with Class 2 Device (LG5 Diesel)Scan Tool Does Not Communicate with Class 2 Device (L18 Gas) Scan Tool Does Not Communicate with Class 2 Device (L18 Gas)
* Scan Tool Does Not Communicate with Electronic Brake Control Module Scan Tool Does Not Communicate with Electronic Brake Control Module