1. Ignition OFF, disconnect the harness connector of the yaw rate sensor.
2. Ignition ON, verify that a test lamp illuminates between the module voltage circuit and ground.
锟斤拷If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the
EBCM.
3. Ignition OFF, test for less than 5 ohms between the module ground circuits and ground.
锟斤拷If greater than the specified value, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the EBCM.
4. If all circuits test normal, replace the yaw rate sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Wiring Repairs/GMLAN Wiring Repairs)
* ABS Description and Operation (See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems/Description and
Operation/ABS Description and Operation) for the ABS - Hybrid
* Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement (See: Brakes and Traction Control/Antilock Brakes / Traction
Control Systems/Yaw Rate Sensor/Service and Repair/Less than 3900 kg (8600 lb) GVW) for the ABS - Non-Hybrid Less than 3900 kg
(8600 lb) GVW
* Vehicle Yaw Sensor with Vehicle Lateral Accelerometer Replacement (See: Brakes and Traction Control/Antilock Brakes / Traction
Control Systems/Yaw Rate Sensor/Service and Repair/Less than 3900 kg (8600 lb) GVW) for the ABS - Non-Hybrid Greater than/Equal to
3900 kg (8600 lb) GVW
* Control Module References (See: Testing and Inspection/Programming and Relearning) for module replacement, setup, and programming
U2129
DTC U2105-U2199
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 Descriptor
DTC U2142 00
- Lost Communication With Yaw Rate Sensor (YRS)
Circuit/System Description
Modules connected to the CAN bus serial data circuits 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 and Lateral Acceleration 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 (See: Powertrain
Management/Computers and Control Systems/Information Bus/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 supervised periodic message that includes the transmitter module availability has not been received.
Action Taken When the DTC Sets
