C0281

DTC C0281 or C081

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC C0281 00
- Dynamic Rear Proportioning (DRP) Performance




Circuit/System Description

The dynamic rear proportioning (DRP) is a control system that replaces the hydraulic proportioning function of the mechanical proportioning valve in the base brake system. The DRP control system is part of the operating software in the electronic brake control module (EBCM). The DRP uses active control with the existing antilock brake system (ABS) in order to regulate the vehicle's rear brake pressure.


Conditions for Running the DTC

One or more faults have been detected by the EBCM in the ABS or traction control system (TCS).


Conditions for Setting the DTC

One of the following conditions exists:

* DTC C0121, C0116, C0900, or C0550 sets.
* DTC C0899 sets and the system voltage is less than 8.5 volts.
* Two wheel speed sensor DTCs on the same axle set.



Action Taken When the DTC Sets

* The EBCM disables the DRP for the duration of the ignition cycle.
* The brake warning indicator illuminates.



Conditions for Clearing the DTC

* The condition for the DTC is no longer present.
* The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.



Diagnostic Aids

This DTC is for information only. As an aid to the technician, this DTC indicates that another DTC exists that fails DRP.


Reference Information
Schematic Reference

Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for Scan Tool Information


Circuit/System Verification

Verify that the following DTCs are not set: DTC C0121, C0116, C0900, or C0550.

If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions)