Antilock Brakes / Traction Control Systems

DTC C0870

Circuit Description

The electronic brake control module (EBCM) supplies voltage to the brake pressure sensor, steering angle sensor, and yaw rate/lateral accelerometer sensor. This voltage is monitored by the EBCM for an over or under voltage condition.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0870 Device Voltage Reference Output Circuit

Conditions for Running the DTC

* The ignition is ON.
* Ignition voltage is greater than 8 volts.

Conditions for Setting the DTC

One of the follow conditions exists for 0.1 second:

* The sensor supply voltage is greater than 5.2 volts.
* The sensor supply voltage is less than 4.8 volts.

Action Taken When the DTC Sets

* The EBCM disables the Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
* The adaptive cruise control (ACC) braking function disabled.
* The Traction Control System (TCS) is degraded.
* The traction control and active handling indicator turns ON.
* The driver information center (DIC) displays the Service Active Handling message.

Conditions for Clearing the DTC

* The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The following conditions can cause this concern:

* The sensor supply circuit is open, shorted to ground, or shorted to battery.
* Internal sensor malfunction
* Internal EBCM malfunction

Test Description

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

5. Tests for a short at the brake pressure sensor.
6. Tests for a short at the steering wheel position sensor.
7. Tests for a short at the yaw rate/lateral accelerometer sensor.

Step 1 - Step 7:

Step 8 - Step 16: