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Home >> Cadillac >> 2012 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 533 (Data Link Communication System) >> Diagnostic Information and Procedures >> Scan Tool Does Not Communicate with E and C Data Line
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Scan Tool Does Not Communicate with E and C Data Line

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
Scan Tool Does Not Communicate with E and C Data Line

Step Action Yes No
1 Does the scan tool power up? Go to Step 2  Go to Scan Tool Does Not Power Up 
2
  1. Turn ON the ignition, leaving the engine OFF
  2. Attempt to communicate with each module on the E and C Data Line.
Does the scan tool communicate with the Radio or CD Changer?		 Go to Step 5  Go to Step 3 
3 Test the battery positive voltage circuits and the ignition voltage circuits of the Radio for an open. Refer to Control Module References in Body Control System for Radio schematics. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Control Module References in Body Control System for the applicable Diagnostic System Check Go to Step 4 
4
  1. Turn the ignition OFF.
  2. Test the ground circuits of the Radio for an open. Refer to Control Module References in Body Control System for Radio schematics. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Control Module References in Body Control System for the applicable Diagnostic System Check Go to Step 5 
5 Test the battery positive voltage circuits and the ignition voltage circuits of the module that does communicate with the scan tool for an open. Refer to Control Module References in Body Control System for the applicable schematics. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Control Module References in Body Control System for the applicable Diagnostic System Check Go to Step 6 
6
  1. Turn the ignition OFF.
  2. Test the ground circuits of the module that does not communicate with the scan tool for an open. Refer to Control Module References in Body Control System for the applicable schematics. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Control Module References in Body Control System for the applicable Diagnostic System Check Go to Step 7 
7
  1. Turn the ignition ON.
  2. Disconnect the scan tool if connected.
  3. Test the E and C Serial Data circuit between the DLC connector, Radio and the CD Player, if equipped, for a short to ground or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Control Module References in Body Control System for the applicable Diagnostic System Check Go to Step 8 
8 Test the E and C Serial Data circuit between the DLC connector, Radio and the CD Player, if equipped, for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Control Module References in Body Control System for the applicable Diagnostic System Check Go to Step 9 
9 Replace the module that will not communicate with the scan tool. Refer to Control Module References in Body Control System for the applicable replacement procedure.
Is the repair complete?		 System OK -
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