2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 2043
* Use the DMM MIN/MAX function to capture/locate intermittent conditions.
* Short to ground will also set multiple history no communication codes for GMLAN high speed modules.
Reference Information
Schematic Reference
Data Communication Schematics (See: Powertrain Management/Computers and Control Systems/Information Bus/Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)
Description and Operation
Data Link Communications Description and Operation (See: Powertrain Management/Computers and Control Systems/Information
Bus/Description and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Circuit/System Testing
Note: Use the schematic to determine which control modules are on the BCM communications enable circuit 23, X4.
1. Ignition OFF, disconnect the harness connector at the most easily accessible control module on the BCM communications enable circuit.
2. Ignition ON, retest for current DTCs. DTC U2099 should remain current.
瀚慖f the DTC becomes history, replace the control module.
3. With the prior control modules disconnected, repeat steps 1 and 2 for each control module on the circuit except the BCM.
4. Ignition OFF, disconnect the X 4 harness connector at the K9 BCM.
5. Test for infinite resistance between the serial data communication enable circuit terminal 23 and ground.
瀚慖f less than infinite resistance, repair the enable circuit for a short to ground.
6. If all circuits tests normal, replace the K9 BCM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for module replacement, setup, and programming
U2100
DTC U0073 or U2100
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC U0073 00
- Control Module Communication Bus Off
