Diagnostic Aids

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: The scan tool communicate with the BCM on class 2 bus and on Keyword 2000 bus for the rest of modules that functionally communicate on CAN bus. The above DTCs are set for communication among modules on CAN bus. For example, if DTC U2108 is set, the scan tool may communicate properly with the EBCM, but EBCM may not functionally communicate properly on CAN bus. Refer to Data Link Communications Description and Operation .

A poor connection at the inoperative module may cause this code to set.
An improperly powered module may cause this code to set.

DTC U2105-U2199

Step	Action	Yes	No
Schematic Reference: Data Communication Schematics Connector End View Reference: Data Communication Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	IMPORTANT: Use the DTC list in DTC Descriptors to determine which is the module that is not communicating on CAN bus. Test the following circuits of the module that is not communicating on controller area network (CAN) bus for an open or a short to ground: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage circuits Refer to the following: Control Module References for the applicable schematic Circuit Testing Wiring Repairs Did you find and correct the condition?	Go to Step 7	Go to Step 3
3	Turn OFF the ignition. Test the ground circuits of the module that is not communicating on CAN bus for an open. Refer to the following: Control Module References for the applicable schematic Circuit Testing Wiring Repairs Did you find and correct the condition?	Go to Step 7	Go to Step 4
4	Test the CAN serial data circuits of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	Go to Step 7	Go to Step 5
5	Inspect the harness connectors of the module that is not communicating on CAN bus for poor connections and terminal tension at the following circuits: The battery positive voltage input circuits The battery positive voltage output circuits The ignition voltage input circuits The ignition voltage output circuits The switched battery positive voltage supply circuits The ground circuits The CAN serial data circuits Refer to the following: Control Module References for the applicable schematic Testing for Intermittent Conditions and Poor Connections Connector Repairs Did you find and correct the condition?	Go to Step 7	Go to Step 6
6	Replace the module that is not communicating on CAN bus. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?	Go to Step 7	-
7	Use the scan tool in order to clear the DTCs. Does the scan tool still display other current DTCs?	Go to Diagnostic System Check - Vehicle	-