Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC U1500 01: Inter-Device Dedicated Bus 1 Short to BatteryDTC 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 | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
B+ - Window Motor | U1511, U1512 | U1511, U1512 | -- |
Ignition - Electronic Compass Module | U1511 | U1511 | -- |
Serial Data - Electronic Compass Module, Terminal 3 | U1511 | U1511 | U1511 |
Serial Data- Driver Window Motor, Terminal 5 | U1500 02 | U1511 | U1500 01 |
Serial Data - Passenger Window Motor, Terminal 5 | U1500 02 | U1512 | U1500 01 |
Ground - Electronic Compass Module | -- | U1511 | -- |
Ground - Window Motor | -- | U1511¹, U1512¹ | -- |
¹ Either or both DTC may set depending on the location of the open/high resistance. | |||
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 the body control module (BCM) through a bi-directional data circuit (LIN).
Conditions for Running the DTC
The system voltage is between 9-16 volts.
Conditions for Setting the DTC
U1500 01
When there is a short to voltage in the local interconnect network bus circuit.
U1500 02
When there is a short to ground in the local interconnect network bus circuit.
U1511, U1512
The DTC will set when there is an open/high resistance in the local interconnect network bus circuit, or an open in the voltage or ground circuits of the motor or module.
Action Taken When the DTC Sets
U1500
The individual LIN bus will be inoperative, disabling all windows on one side of the vehicle.
U1511
| • | If set in the driver door lock window switch or passenger door lock window switch, 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 U1511 and U1512 should set. If open after the first splice, the individual window will be inoperative and a single DTC should set. |
| • | If set in the BCM, the compass is inoperative in the DIC. |
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 U1511 and U1512 should set. If open after the first splice, the individual window will be inoperative and a single DTC should set.
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 local 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. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Data Link Communications Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
- With a scan tool, verify that DTC U1511 is not set in the BCM.
- Perform the Window Malfunction Test
| ⇒ | If DTC U1511 is set in the BCM, perform the Compass Malfunction Test. |
Circuit/System Testing
Compass Malfunction Test
- Ignition OFF, disconnect the harness connector at the electronic compass module.
- Ignition OFF, test for less than 5.0 ohm between the ground circuit terminal 2 and ground.
- Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 1 and ground.
- Test for 6.0-7.0 volts between the LIN Bus circuit terminal 3 and ground.
- If all circuits test normal, replace the electronic compass module.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. |
| ⇒ | If greater than the specified range, test the LIN Bus circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified range, test the LIN Bus circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Window Malfunction Test
- Ignition OFF, disconnect the harness connector at the appropriate window motor.
- Ignition OFF, test for less than 2.0 ohm between the ground circuit terminal 4 and ground.
- Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 3 and ground.
- Test for 6.0-7.0 volts between the LIN circuit terminal 5 and ground.
- Ignition OFF, reconnect the harness connector at the window motor.
- Ignition ON, observe the appropriate scan tool Window Motor Fault Status parameter while raising and lower the window. The parameter should read No Fault.
- If all circuits test normal, replace the appropriate door module.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If greater than the specified range, test the LIN circuit for a short to voltage. If the circuit tests normal, replace the applicable door module. |
| ⇒ | If less than the specified range, test the LIN circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the applicable door module. |
| ⇒ | If the parameter reads Motor Fault, Hall Fault, Memory Fault, LIN Fault, Anti-Trap Fault or Thermo Active, test or replace the appropriate power window motor. |
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.
Control Module References for window, and door lock switches (door modules), window regulator motors, or electronic compass module replacement, setup, and programming
