H2 V8-6.2L (2008)
Information Bus: Symptom Related Diagnostic Procedures
Symptoms - Data Communications
Symptoms - Data Communications
Important: The following steps must be completed before using the symptom tables.
1. Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) before using the symptom tables in order to verify that all of the following are true:
*
There are no DTCs set.
*
The control modules can communicate via the serial data links.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to Data Link Communications Description and
Operation (See: Description and Operation) .
Visual/Physical Inspection
*
Inspect for aftermarket devices which could affect the operation of the systems. Refer to Checking Aftermarket Accessories (See:
Diagrams/Diagnostic Aids/General Electrical Diagnostic Procedures/Checking Aftermarket Accessories) .
*
Inspect the easily accessible or visible system components for obvious damage or conditions which 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 (
See: Diagrams/Diagnostic Aids/General Electrical Diagnostic Procedures/Circuit Testing/Testing For Intermittent and Poor Connections) .
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
*
Scan Tool Does Not Power Up (See: Scan Tool Does Not Power Up)
*
Scan Tool Does Not Communicate with High Speed GMLAN Device (See: Scan Tool Does Not Communicate with High Speed GMLAN Device
)
*
Scan Tool Does Not Communicate with Low Speed GMLAN Device (See: Scan Tool Does Not Communicate with Low Speed GMLAN Device)
Scan Tool Does Not Power Up
Scan Tool Does Not Power Up
Diagnostic Instructions
*
Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
*
Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
*
Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure Instructions)
provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated by an industry wide standard, and is
required to provide the following:
*
Scan tool B+ voltage at terminal 16
