GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 Escalade ESV 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C0201

Circuit Description

The system relay, located within the electronic brake control module (EBCM), supplies battery voltage to all of the valve solenoids and to the precharge pump motor. When the relay contacts close, the EBCM monitors the voltage supplied to the valve solenoids and compares this voltage to monitored ignition voltage.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0201 Antilock Brake System (ABS) Enable Relay Contact Circuit

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

Either of the following conditions may cause the DTC to set:

    • The EBCM detects that the voltage supplied to the valve solenoids is less than 65 percent of monitored ignition voltage for 50 milliseconds.
    • The EBCM detects that the relay contacts do not open when the relay is not energized.

Action Taken When the DTC Sets
    • The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES)/dynamic rear proportion (DRP).
    • The ABS indicator turns ON.
    • The traction OFF indicator turns ON.
    • The message center displays the service stability system message.
    • The brake warning indicator turns ON.
    • The message center displays the service brake system message.

Conditions for Clearing the DTC

The Conditions for Setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Refer back to the diagnostic table, steps 3 through 7, if this DTC continues to set intermittently.

Test Description

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

  1. A shorted ABS pump motor may damage the contacts within the system relay. It is imperative that the steps in the table be followed to prevent damage to a replacement EBCM.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Use the scan tool to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Turn ON the ignition.

Does the DTC reset?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Separate the electronic brake control module (EBCM) from the brake pressure modulator valve (BPMV). Refer to Electronic Brake Control Module Replacement .
  2. Use a DMM in order to measure the resistance across the ABS pump motor.

Does the resistance measure within the specified range?

0.3-1 ohms

Go to Step 4

Go to Step 6

4

Use a DMM in order to measure the resistance between the high side of the pump motor and a good ground.

Does the resistance measure less than the specified value?

OL

Go to Step 6

Go to Step 5

5

Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 7

--

6

Important: Following EBCM replacement, perform the set-up procedure for the EBCM and perform the Yaw Rate Reference Table Reset Procedure. Use the scan tool to perform the Tire Size Calibration procedure.

    • Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.
    • Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement .

Did you complete the replacements?

--

Go to Step 7

--

7
  1. Use the scan tool to clear the DTCs.
  2. Turn OFF the ignition for 5 seconds.
  3. Turn ON the ignition.

Does the DTC reset?

--

Go to Step 3

System OK