2010 Cadillac CTS Sedan AWD V6-3.0L Page 2041

2010 Cadillac CTS Sedan AWD V6-3.0L Page 2041

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.

* Control Module References (See: Testing and Inspection/Programming and Relearning) for window, and door lock switch (door module) or

window regulator motor replacement, setup, and programming

* Electronic Compass Module Replacement (Sedan) (See: Instrument Panel, Gauges and Warning Indicators/Compass/Service and Repair

)Electronic Compass Module Replacement (Wagon) (See: Instrument Panel, Gauges and Warning Indicators/Compass/Service and Repair)

U1512

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

the window as requested.

The DDM and PDM supply their respective rear power window switches with a 12-volt reference and signal circuit. The rear power window

switches contain separate resistors for each switch position. When a rear power window switch is activated, the associated door control module

interprets the signal and checks for messages from other vehicle control modules prohibiting the window movement. If no prohibitive messages

have been received, the door control module sends a LIN serial data message to the appropriate power window motor commanding the requested

window position.

The driver information center (DIC) displays the compass based on serial data message from the BCM. The compass module communicates with