Inter-Device Dedicated Bus 1

DTC U1500

DTC Descriptor

DTC U1500 00 Inter-Device Dedicated Bus 1

Diagnostic Fault Information:

Diagnostic Fault Information

Circuit/System Description
Modules connected to the CAN bus serial data circuits are high speed serial data modules that monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.

The electronic brake control module (EBCM) activates the other modules connected to the CAN serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The EBCM, Yaw Rate Sensor, and the Steering Angle Sensor are the only modules connected to the CAN bus serial data circuits. For more information on CAN bus serial data refer to [Data Link Communications Description and Operation].

Conditions for Running the DTC
^ The system voltage is between 9-16 volts.
^ The vehicle power mode master requires serial data communication to occur.

Conditions for Setting the DTC
A no communication condition exists on the CAN bus serial data for the EBCM.

Action Taken When the DTC Sets
^ The Vehicle stability Enhancement System (VSES), if equipped, and Traction Control System (TCS) will not function.
^ System OFF lamps will illuminate for these systems.

Conditions for Clearing the DTC
^ A current DTC clears 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
^ An open on 1 CAN Bus circuit will not cause a U1500 DTC.
^ If there are multiple non-communicating modules choose the one farthest from the EBCM.

Reference Information
Schematic Reference
^ [Data Communication Schematics]
^ [Control Module References] Programming and Relearning

Connector End View Reference
[Master Electrical Component List]

Electrical Information Reference
^ [Circuit Testing]
^ [Connector Repairs]
^ [Testing for Intermittent Conditions and Poor Connections]
^ [Wiring Repairs]

Circuit/System Testing
1. Ignition OFF, disconnect the harness connector of the yaw rate sensor.
2. Ignition ON, with a scan tool attempt to retrieve data from the steering wheel angle sensor in Chassis/Electronic Brake Control Module Data should be available.
^ If no data, repair the serial data circuits for a short to ground, short to voltage or an open/high resistance. If the circuits test normal, replace the steering wheel angle sensor.

3. Replace the Yaw rate sensor.

Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure.
^ [GMLAN Wiring Repairs]
^ [Steering Wheel Position Sensor Replacement]
^ [Vehicle Yaw Sensor Replacement]
^ [Control Module References] for module replacement, setup, and programming Programming and Relearning