2010 Cadillac CTS Sedan AWD V6-3.0L Page 2035
Circuit/System Verification
1. Engine running for 10 seconds.
2. Ignition ON, engine OFF, verify the DTC U0400-U05FF is not set.
瀚慖f the DTC U0400-U05FF is set along with other DTCs set, diagnose all other codes first. Refer to Diagnostic Trouble Code (DTC) List -
Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).
瀚慖f the DTC U0400-U05FF is set without other DTCs set, program the control module specified by the DTC descriptor. If the DTC resets,
replace the appropriate control module.
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 control module replacement, setup, and programming
U1500
DTC U1500, U1511, U1512, or U1513
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 U1500 01
- Inter-Device Dedicated Bus 1 Short to Battery
DTC U1500 02
- Inter-Device Dedicated Bus 1 Short to Ground
DTC U1511 00
- Inter-device Dedicated Bus Lost Communication With Device 1
DTC U1512 00
- Inter-device Dedicated Bus Lost Communication With Device 2
Diagnostic Fault Information
Circuit/System Description
The driver door module (DDM) and the front passenger door module (FPDM) communicate with window regulator motors on the local
interconnect network bus 1 and the local interconnect network bus 2 circuits respectively. When the driver power window switch is activated to a
desired position, the DDM examines the request and checks for messages from other vehicle control modules prohibiting window movement. If no
prohibitive messages have been received, the DDM will send a LIN serial data message to the driver door window motor to move the window to
the desired position.
When the DDM receives a request to operate one of the right side passenger windows from the driver master control, a GMLAN serial data
message is sent to the PDM. The PDM examines the request and checks for messages from other vehicle control modules prohibiting the window
movement. If no prohibitive messages have been received, the PDM will send a LIN serial data message to the appropriate window motor to move
