C0273

DTC C0273

Circuit Description

The pump motor relay is part of the electronic brake control module (EBCM) on vehicles without traction control. The pump motor relay is located in the Antilock Brake System (ABS) relay block on vehicles with traction control. The EBCM turns ON and OFF the pump motor relay as deemed necessary in order to activate the pump motor. The pump motor modulates brake hydraulic pressure during an ABS stop.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0273 ABS Motor Relay Open

Conditions for Running the DTC

DTC C0273 can be set anytime the ignition switch is in the ON position.

Conditions for Setting the DTC

The EBCM detects an open in the pump motor circuitry.

Action Taken When the DTC Sets

* The ABS is disabled.
* The ABS warning indicator turns ON.
* The traction control and vehicle stability control (VSC) is disabled, if equipped.
* The VSC warning indicator turns ON, if equipped.

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, high resistance, or short to ground in the battery positive voltage circuit
* An open or high resistance in the motor ground circuit
* 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.

2. This step determines if the DTC is current.
6. This step tests the relay circuits between the ABS relay block and the EBCM for an open, high resistance, or short to ground.
7. This step tests the battery positive voltage circuit for an open, high resistance, or short to ground.
8. This step tests the motor ground circuit for an open or high resistance.

Step 1 - Step 7:

Step 8 - Step 14: