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Home >> GMC >> 2005 >> W 3500 Forward L4-4.8L DSL Turbo >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Scan Tool Does Not Power Up
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Scan Tool Does Not Power Up

Scan Tool Does Not Power Up

Circuit 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 power battery positive voltage at terminal 16.
- Scan tool power ground at terminal 4.
- Common signal ground at terminal 5.

The scan tool will power up with the ignition OFF. Some modules however, will not communicate unless the ignition is ON.

Scan Tool Does Not Power Up

Schematic Reference: Engine Controls Schematics


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