GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 CTS - RHD 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1244

Circuit Description

The electronic brake control module (EBCM) sends a requested torque signal via a dedicated data line. The engine control module (ECM) supplies a pull up voltage of 12 volts that the EBCM switches to ground to create the signal.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The EBCM receives a serial data message from the ECM indicating that the requested torque signal circuit has failed.

Action Taken When the DTC Sets
    • The EBCM disables the TCS for the duration of the ignition cycle.
    • The DIC displays the Service Stability System message.
    • The ABS remains functional.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
    • The electronic brake control module (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:

    • An open in the requested torque signal circuit.
    • An short to ground or voltage in the requested torque signal circuit.
    • A wiring problem, terminal corrosion, or poor connection in the requested torque signal circuit.

Test Description

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

  1. This vehicle is equipped with a ECM which uses an electrically erasable programmable read only memory (EEPROM). When replacing the ECM, the replacement ECM must be programmed.

Step

Action

Value(s)

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the ABS Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

Inspect the EBCM ground and ECM ground, making sure each ground is clean and torqued to the proper specification. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 3

3
  1. Disconnect the EBCM harness connector.
  2. Install the J 39700 universal pinout box using the J 39700-300 cable adapter to the EBCM harness connector and the EBCM connector.
  3. Disconnect the engine control module (ECM) harness connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Measure the voltage from the requested torque signal circuit to a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 4

Go to Step 5

4
  1. Turn OFF the ignition.
  2. Disconnect the J 39700-300 cable adapter from the EBCM connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Test the requested torque signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 6

5
  1. Turn OFF the ignition.
  2. Disconnect the J 39700-300 cable adapter from the EBCM connector.
  3. Test the requested torque signal circuit for the following conditions:
    4. • An open
    • A short to ground
    • A high resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 7

6

Inspect for poor connections the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 8

7

Inspect for poor connections the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 9

8

Important: The replacement ECM must be programmed.

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls - 2.6L and 3.2L.

Did you complete the repair?

--

Go to Step 10

--

9

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Did you complete the repair?

--

Go to Step 10

--

10
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK