U1512
DTC U1500, U1511, U1512, or U1513
DTC Descriptor
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
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
Circuit/System Description
The driver door module (DDM) and the front passenger door module (FPDM) communicate with window regulator motors on the linear interconnect network bus 1 and the linear interconnect network bus 2 circuits respectively. The DDM LIN bus is connected to all window regulator motors on its side of the vehicle, while the FPDM LIN buss is connected to the other window regulator motors. Communication on this network is only between the door modules and the window regulator motors. The window regulator motors are in effect modules. The window regulator motors do not communicate on any other data bus; therefore the door modules, which also communicate on the low speed GMLAN serial data bus will perform all communication with each other. If the driver depresses any window control other than the drivers side on that switch the DDM communicates the information to the FPDM for control.
Conditions for Running the DTC
The system voltage is between 9-16 volts.
Conditions for Setting the DTC
DTC U1511, U1512
The DTC will set when there is an open/high resistance in the linear interconnect network bus circuit, or an open in the voltage or ground circuits of the motor.
DTC U1500 02
When there is a short to ground in the linear interconnect network bus circuit.
DTC U1500 01
When there is a short to voltage in the linear interconnect network bus circuit.
Action Taken When the DTC Sets
DTC U1511, U1512
No window on the specific side of the vehicle will operate if the open is before the first splice from the door module, and both DTC should set. If open after the first splice, the individual window will be inoperative and a single DTC should set.
DTC U1500
The individual LIN bus will be inoperative, disabling all windows on one side of the vehicle.
Conditions for Clearing the DTC
* The current DTC will clear when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
Diagnostic Aids
* A window regulator motor may cause a short to the linear interconnect network bus circuit, and will cause all windows on one side to be inoperative.
* An open/high resistance between the door module and the first splice from the module will cause all windows on one side to be inoperative.
* An open/high resistance between the window regulator motor and the first splice from the motor will cause only one window to be inoperative.
* Use the DMM MIN/MAX function to capture/locate intermittent conditions.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector C2 at the door module.
2. Test for infinite resistance between the door module network bus circuit terminal 3 and ground.
• If less than infinite resistance, test the network bus circuit for a short to ground. If the circuit tests normal, replace window regulator motor.
3. Ignition ON, verify that a test lamp does not illuminate between the door module network bus circuit terminal 3 and ground
• If the test lamp illuminates, test the network bus circuit for a short to voltage. If the circuit tests normal, replace window regulator motor.
4. Ignition OFF, disconnect the harness connector at the inoperative window regulator motor.
5. Test for less than 1.0 ohm of resistance in the network bus circuit between the harness connector C2 terminal 3 of the door module and harness connector terminal 6 of the window regulator motor.
• If greater than 1.0 ohm, repair the network bus circuit for an open/high resistance.
6. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
7. Test for less than 1.0 ohm of resistance between the window regulator motor ground circuit terminal 4 and ground.
• If greater than 1.0 ohm, test the ground circuit for an open/high resistance.
8. If the circuits test normal and only 1 window is inoperative, replace window regulator motor. If the circuit test normal and all windows on one side of the vehicle are inoperative, replace the door module.
Repair Instructions
Important: Each window regulator motor or front window and door lock switch, if replaced needs to be setup for proper operation.
Perform the Diagnostic Repair Verification after completing the repair. Verification Tests
Refer to Control Module References for window, and door lock switch (door module) or window regulator motor replacement, setup, and programming. Programming and Relearning