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 to enhance Antilock Brake System (ABS) braking and vehicle stability if equipped.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0136 Base Brake System Pressure Circuit

Conditions for Running the DTC

The ignition is ON for 1 second.

Conditions for Setting the DTC

One of the following conditions exists for 0.1 second.

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

Action Taken When the DTC Sets

If equipped, the fallowing actions will occur.

    • The EBCM disables the Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
    • Traction Control System (TCS) is degraded.
    • Adaptive cruise control (ACC) braking function is disabled.
    • 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

If equipped, the 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 brake pressure sensor.

Test Description

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

  1. This step tests for the proper voltage output on the 5-volt reference circuit and the proper operation of the signal circuit.

  2. This step tests for possible low 5-volt reference output or a problem with the signal circuit.

  3. This step tests for a short to voltage on the 5-volt reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system if equipped.

  4. This step tests for a problem with the low reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system if equipped.

Step

Action

Values

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?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the brake fluid pressure sensor and the signal circuit of the brake fluid pressure sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the Brake Pressure Sensor parameter.

Does the scan tool indicate that the Brake Pressure Sensor parameter is between the specified voltage range?

4.9-5.1 V

Go to Step 8

Go to Step 3

3

With the 3-amp fused jumper wire still connected, does the scan tool indicate that the Brake Pressure Sensor parameter is below the specified voltage value?

4.9 V

Go to Step 5

Go to Step 4

4

Test the 5-volt reference circuit of the brake fluid pressure sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 13

Go to Step 7

5

Test the 5-volt reference circuit of the brake fluid pressure sensor for the following conditions:

    • An open
    • A short to ground
    • A high resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 13

Go to Step 6

6

Test the signal circuit of the brake fluid pressure sensor for the following conditions:

    • An open
    • A short to ground
    • A high resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

7

Test the signal circuit of the brake fluid pressure sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

8

Test the low reference circuit of the brake fluid pressure sensor for the following conditions:

    • An open
    • A short to voltage
    • A high resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 13

Go to Step 9

9

Inspect for poor connections at the harness connector of the brake fluid pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

10

Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

11

Replace the brake fluid pressure sensor. Refer to Brake Pressure Modulator Valve Pressure Sensor Replacement .

Did you complete the replacement?

--

Go to Step 13

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12

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

Did you complete the replacement?

--

Go to Step 13

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13

  1. Clear the DTCs using the scan tool.
  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