For 1990-2009 cars

### Circuit Description

As the wheel spins, the wheel speed sensor produces an AC signal. The EBCM uses the frequency of the AC signal to calculate the wheel speed.

### Conditions for Running the DTC

#### C0035, C0040, C0045, and C0050

The ignition is in the ON position.

#### C0036, C0041, C0046, and C0051

• | DTCs C0035, C0040, C0045, and C0050 are not set.

• | The brake switch is OFF.

• | The ABS is not active.

### Conditions for Setting the DTC

#### C0035, C0040, C0045, and C0050

The EBCM detects one of the following conditions in the wheel speed sensor circuits:

• | An open

• | A short to ground

• | A short to voltage

#### C0036, C0041, C0046, and C0051

The EBCM detects a rapid change in the wheel speed which is determined to be unreasonable.

### Action Taken When the DTC Sets

The following actions occur:

• | The EBCM disables the ABS for the duration of the ignition cycle.

• | The ABS indicator turns ON.

### Conditions for Clearing the DTC

#### C0035, C0040, C0045, and C0050

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

#### C0036, C0041, C0046, and C0051

• | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

• | After the DTC is cleared, the ABS indicator will remain ON until the vehicle is road tested to verify the repair. Once the vehicle has been driven at a speed above 16 km/h (10 mph) for 20 seconds with no malfunctions present, the EBCM will turn OFF the ABS indicator.

### Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

• | A short to ground or a short to voltage in the wheel speed sensor circuitry

• | An open or high resistance in the wheel speed sensor circuitry

• | A malfunctioning wheel speed sensor

• | An internal EBCM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

### Test Description

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

1. This step tests the wheel speed sensor for the proper resistance value.

2. This step ensures that the wheel speed sensor generates the proper voltage.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Antilock Brake System Schematics
1 | Did you perform A Diagnostic System Check - ABS? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Set up the scan tool snap shot feature to trigger for this DTC.
4. Drive the vehicle at a speed greater than the specified value for 30 seconds.

Does the scan tool indicate that this wheel speed DTC set?

20 km/h (12 mph)

Go to Step 3

Go to Diagnostic Aids

3 |

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Disconnect the wheel speed sensor connector.
3. Measure the resistance across the wheel speed sensor.

Does the resistance measure within the specified range?

1120-2520 ohms

Go to Step 4

Go to Step 8

4 |

1. Spin the wheel.
2. Measure the AC voltage across the wheel speed sensor.

Does the AC voltage measure greater than the specified value?

100 mV

Go to Step 5

Go to Step 8

5 | Inspect for poor connections at the harness connector of the wheel speed sensor. 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 6
6 |

1. Disconnect the EBCM harness connector.
2. Test the wheel speed sensor circuits for the following:

• | An open

• | A short to ground

• | A short to voltage

• | Shorted together

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

7 | Inspect for poor connections at the harness connector for 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 | Replace the wheel speed sensor. Refer to Front Wheel Speed Sensor Replacement or Rear Wheel Speed Sensor Replacement . Did you complete the replacement? | -- | Go to Step 10 | --
9 | Replace the Brake Pressure Modulator Valve (BPMV). Refer to Brake Pressure Modulator Valve Assembly Replacement . Did you complete the replacement? | -- | 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