GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2002 🢒 Eldorado 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1236

Circuit Description

The electronic brake control module (EBCM) monitors the voltage level available for system operation. A low voltage condition prevents the system from operating properly.

Conditions for Running the DTC

The vehicle speed is greater than 8 km/h (5 mph).

Conditions for Setting the DTC

The ignition voltage is less than 10.5 volts.

AND

One of the following conditions exists for 0.72 seconds:

    • With the ABS inactive, the solenoid relay voltage is less than 10.5 volts.
    • With the ABS active, the solenoid relay voltage is less than 9.6 volts.

Action Taken When the DTC Sets

If equipped, the following actions occur:

    • The EBCM disables the ABS/TCS/VSES for the duration of the ignition cycle.
    • The ABS indicator turns ON.
    • The Traction Control indicator turns ON.
    • The DIC displays the Service Stability System message.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present (the DTC is not current) and you used the scan tool Clear DTC function.
    • The condition for the DTC is no longer present (the DTC is not current) and you used the On-Board Diagnostics Clear DTC function.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 50 consecutive drive cycles.

Diagnostic Aids
    • Test the charging system. Refer to Diagnostic System Check - Engine Electrical in Engine Electrical.
    • Possible causes of this DTC are the following conditions:
       - A charging system malfunction
       - An excessive battery draw
       - A weak battery
       - A faulty system ground

Test Description

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

  1. Uses the scan tool in order to inspect the voltage to the EBCM.

    2.

  2. Uses the scan tool in order to inspect the voltage to the body control module (PZM). A low voltage value in multiple modules indicates a concern in the charging system.

    3.

  3. Verifies that the condition is still present.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

Did you perform the ABS Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Install a scan tool.
  2. Start the engine.
  3. With the scan tool, observe the Switched System Battery Power parameter in the Delco/Bosch ABS/TCS ICCS (if equipped) data list.

Does the scan tool indicate the voltage is greater than the specified value?

10.5 V

Go to Diagnostic Aids

Go to Step 3

3

With the scan tool, observe the Battery Voltage parameter in the Body Control Module data list.

Does the scan tool indicate the voltage is greater than the specified value?

10.5 V

Go to Step 4

Go to Diagnostic System Check - Engine Electrical in Engine Electrical

4
  1. Turn OFF the ignition.
  2. Disconnect the EBCM harness connector.
  3. Install the J 39700 universal pinout box using the J 39700-25 cable adapter to the EBCM harness connector only.
  4. Test the ground circuits of the EBCM including the EBCM ground for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 5

5

  1. Reconnect the EBCM harness connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 6

Go to Diagnostic Aids

6

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

Did you complete the repair?

--

Go to Step 7

--

7
  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