GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The electronic brake control module (EBCM) uses the input from the brake fluid pressure sensor 2 to enhance Antilock Brake System (ABS) braking and vehicle stability if equipped.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C1101 Base Brake System Pressure Sensor 2 Range

Conditions for Running the DTC

    • The ignition is ON for 1 second and greater than 8 volts.
    • The 5-volt reference to the secondary brake pressure sensor is in range.

Conditions for Setting the DTC

    • The secondary brake fluid pressure sensor signal is greater than 4.9 volts.
    • The secondary brake fluid pressure sensor signal is less than 0.15 volt.

Action Taken When the DTC Sets

If equipped, the following actions will occur:

    • The EBCM disables the vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
    • The EBCM disables the traction control system (TCS) for the duration of the ignition cycle.
    • The Traction Control Off indicator turns ON.
    • The driver information center (DIC) displays the Service Stability System and Service Traction System 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 brake pressure sensors are internal to the EBCM assembly and cannot be diagnosed or replaced separately. If equipped, the secondary brake pressure sensor 5-volt reference circuit and low reference circuit is shared with other components in the vehicle stability system. DTCs can set for other components that share circuits with the secondary brake pressure sensor.

Test Description

The number below refers to the step number on the diagnostic table.

  1. The EBCM supplies a 5-volt reference to several sensors. DTC C0870 is set if the 5-volt reference voltage is out of range.

Step

Action

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Is DTC C0870 set also?

Go to DTC C0870

Go to Step 3

3

Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 4

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within normal driving conditions.

Does the DTC reset?

Go to Step 1

System OK