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Test Description

WARNING: This page is about a different car, the 2006 GMC Sierra, 2006 GMC Cab & Chassis Sierra, 2006 Chevrolet Silverado, and 2006 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The number below refers to the step number on the diagnostic table.

  1. 4:  If the battery positive voltage and ground circuits of the DLC are functioning properly, the malfunction must be due to the scan tool.
Scan Tool Does Not Power Up

Step Action Yes No
Schematic Reference: Data Link Connector (DLC) Schematics 
Connector End View Reference: Computer/Integrating Systems Connector End Views 
1 Test the battery positive voltage circuit of the data link connector (DLC) for an open or a short to ground. Refer to the following procedures in Wiring Systems:
Did you find and correct the condition?
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information Go to Step 2 
2 Test the ground circuits of the DLC for an open or high resistance. Refer to the following procedures in Wiring Systems:
Did you find and correct the condition?
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information Go to Step 3 
3 Inspect for poor connections and terminal tension at the DLC. Refer to the following procedures in Wiring Systems:
Did you find and correct the condition?
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information Go to Step 4 
4 The scan tool may be malfunctioning. Refer to the scan tool user guide.
Did you obtain a properly operating scan tool?
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information -