For 1990-2009 cars

### Circuit Description

The electronic brake control module (EBCM) uses the input from the brake fluid pressure sensor for more accurate braking control during vehicle stability enhancement system (VSES).

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0137 Base Brake System Pressure Circuit Range

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description .

DTC Symptom | DTC Symptom Descriptor
--- | ---
11 | Above Maximum Threshold
12 | Below Maximum Threshold

### Conditions for Running the DTC

• | The ignition is turned ON.

• | Ignition voltage is greater than 8 volts.

### Conditions for Setting the DTC

Within 3 deceleration cycles, the brake fluid pressure is below 345 kPa (50 psi).

### Action Taken When the DTC Sets

• | The EBCM disables the VSES and traction control for the duration of the ignition cycle.

• | The traction control indicator turns ON.

• | The driver information center (DIC) displays the Service Vehicle Stability message.

• | The antilock brake system (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 EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Diagnostic Aids

• | Find out from the driver under what conditions the DTC was set (when the DIC displayed the Service Active Handling message). This information will help to duplicate the failure.

• | The snapshot function on the scan tool can help find an intermittent DTC.

• | A deceleration cycle consists of the following sequence:

1. | The vehicle speed is greater than 24 km/h (15 mph).

2. | The vehicle decelerates more than 8 km/h/second (5 mph/second) for 2 seconds.

3. | The vehicle speed decelerates to less than 16 km/h (10 mph).

### Test Description

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

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

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

3. 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. 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? | -- | 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 in between the specified voltage range

4.5-5.5V

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 in below the specified voltage value? | 4.5V | 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 12 | Go to Step 7
5 | Test the 5-volt reference circuit of the brake fluid pressure sensor for the following conditions:

• | Open

• | Short to Ground

• | High Resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 6

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

• | Open

• | Short to Ground

• | High Resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

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 12 | Go to Step 11
8 | Test the low reference circuit of the brake fluid pressure sensor for the following conditions:

• | Open

• | Short to voltage

• | High resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

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 12 | Go to Step 10
10 | Replace the brake fluid pressure sensor. Refer to Brake Pressure Modulator Valve Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 12 | --
11 | Replace the EBCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | --
12 |

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