U0073

DTC U0073

Circuit Description

The controller area network (CAN) circuits provide a communication network between the electronic brake control module (EBCM), steering wheel position sensor, yaw rate sensor, and the data link connector (DLC).

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC U0073 CAN Bus Communication

Conditions for Running the DTC

DTC U0073 can be set anytime the ignition switch is in the ON position.

Conditions for Setting the DTC

The EBCM detects a open, high resistance, or short in the CAN circuits.

Action Taken When the DTC Sets

* The Antilock Brake System (ABS) warning indicator turns ON.
* The vehicle stability control (VSC) warning indicator turns ON.
* The VSC and traction control is disabled.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

* An open or high resistance in the CAN - high or CAN - low circuits
* A short between the CAN - high and CAN - low circuits
* A short to ground in the CAN - high or CAN - low circuits
* A short to voltage in the CAN - high or CAN - low circuits
* A steering wheel position sensor malfunction
* A yaw rate sensor malfunction
* An internal EBCM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics

Test Description

The numbers below refer to the step numbers on the diagnostic table.

7. Test the CAN - high and CAN - low circuits for an open or high resistance.
8. Test the CAN - high and CAN - low circuits for a short between circuits.

Step 1 - Step 8:

Step 9 - Step 15:

Step 16 - Step 22: