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Home >> Cadillac >> 2003 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 617 (Data Link Communication System) >> Diagnostic Information and Procedures >> DTC U2100: Controller Area Network (CAN) Bus Communication >> Conditions for Clearing the MIL/DTC
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Conditions for Clearing the MIL/DTC

WARNING: This page is about a different car, the 2004 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
DTC U2100

Step Action Yes No
Schematic Reference: Data Link Connector (DLC) Schematics 
Connector End View Reference: Master Electrical Component List and Inline Harness Connector End Views
1 Did you perform the Diagnostic System Check for the system exhibiting the symptom? Go to Step 2  Go to Control Module References in Body Control System
2
  1. Connect a scan tool to the vehicle.
  2. Use the scan tool in order to clear the DTC.
  3. Turn OFF the ignition.
  4. Disconnect the TCM.
  5. Turn the ignition ON, with the engine OFF.
  6. Use the scan tool to view DTCs in the ECM.
Does the DTC U2100 reset?		 Go to Step 3  Go to Step 4 
3
  1. Turn OFF the ignition.
  2. Disconnect the ECM and TCM connectors.
  3. Test both the CAN high and low circuits for the following conditions:
    • A short to ground
    • A short to voltage
    • A short to each other
Turn ON the ignition, with the engine OFF when you test for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition?		 Go to Step 8  Go to Step 5 
4 Inspect for poor connections at the TCM harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 8  Go to Step 6 
5 Inspect for poor connections at the ECM harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 8  Go to Step 7 
6
IMPORTANT: Perform the programming or set-up procedure for the replaced control module, if required.
Replace the TCM. Refer to Control Module References in Body Control System.Did you complete the replacement?		 Go to Step 8  -
7
IMPORTANT: Perform the programming or set up procedure for the replaced control module if required.
Replace the ECM. Refer to Control Module References in Body Control System.Did you complete the replacement?		 Go to Step 8  -
8
  1. Reconnect all modules not already connected.
  2. Use the scan tool in order to clear the DTCs.
  3. Turn OFF the ignition switch.
  4. Wait at least 10 seconds.
  5. Turn the ignition ON, with the engine OFF.
  6. Retrieve DTCs from the ECM and TCM.
Does the DTC reset ?		 Go to Step 2  System OK
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