For 1990-2009 cars
ABS Components
Cell 44: Wheel Speed Sensors
Handling ESD Sensitive Parts Notice

### Circuit Description

The Electronic Brake Control Module (EBCM) receives right rear wheel speed sensor voltage signal through terminal 15 and terminal 16. As a toothed ring passes by the wheel speed sensor, changes in the electromagnetic field cause the wheel speed sensor to produce a small AC voltage signal. This signal's frequency is proportional to the wheel speed.

### Conditions for Clearing the DTC

• | DTC C0051 will set when the EBCM detects a sudden change in the right rear wheel speed determined to be unreasonable.

• | DTC C0051 can be set anytime.

### Action Taken When the DTC Sets

• | A malfunction DTC stores

• | The ABS disables

• | The ABS warning indicator turns ON

### Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used. If the right rear wheel speed signal is still incorrect, DTC C0051 will set again as a current DTC and the ABS warning indicator remains ON.

### Diagnostic Aids

Inspect for the following when diagnosing this part of the Antilock Brake System (ABS):

• | Loose right rear wheel speed sensor

• | Worn right rear suspension and or drivetrain components

• | Right rear wheel speed sensor physically damaged

• | Right rear wheel speed sensor reluctor wheel toothed ring damaged

Perform a careful visual inspection of the following items:

• | The right rear wheel speed sensor toothed ring

• | The right rear wheel bearing

• | The right rear wheel speed sensor

An intermittent malfunction is most likely caused by a poor connection rubbed thorough wire insulation or a wire that is broken inside the insulation.

If the customer comments reflect that the ABS indicator lamp is ON only during humid conditions (rain, snow, vehicle wash), thoroughly inspect the right rear wheel speed sensor circuitry for signs of water intrusion.

Thoroughly inspect any circuitry that is suspected or causing the intermittent complaint for the following conditions:

• | Backed-out terminals

• | Improper mating

• | Broken locks

• | Improperly formed or damaged terminals

• | Poor terminal to wiring connections

• | Physical damage to the wiring harness

| Important: Wheel speed sensor resistance increases with an increase in sensor temperature. When measuring for a short to ground in a wheel speed sensor wiring circuit, manually switch the J 39200 (Digital Multimeter) to the Meg-Ohms range. This will ensure a high resistance short to ground can be found. See J 39200 owners manual.

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

1. Tests electrical circuits between the wheel speed sensor and the Electronic Brake Control Module (EBCM). If an open, short to ground, or short to voltage is present circuit repairs must be done first.

2. Excessive tire and or wheel assembly waddle and/or play can set this DTC due to excessive wheel speed fluctuations.

3. Tests for a physically damaged wheel speed sensor.

4. Tests for a physically damaged wheel speed sensor reluctor wheel.

5. Tests the internal resistance of the wheel speed sensor for proper values.

6. Tests the voltage output performance of the wheel speed sensor.

7. Tests for wheel speed sensor circuits shorted together.

8. Tests for poor connections at electrical connectors.

9. Determines whether the condition is intermittent and not due to a malfunctioning EBCM.

10. Performs Electronic Brake Control Module (EBCM) repair confirmation after completed repairs.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 |

1. Connect a scan tool to the OBD2 Data Link Connector (DLC).
2. Turn the ignition switch to the ON position.
3. Select Diagnostic Trouble Codes (DTC) on the scan tool.
4. Select DTC Information on the scan tool.
5. Select Current DTC on the scan tool and test for possible Current DTCs.
6. Select History DTCs on the scan tool and test for possible History DTCs.

Is DTC C0050 set as current or history DTC?

--

Go to DTC C0050 RR Wheel Speed Circuit Malfunction

Go to Step 3

3 | Test the right rear wheel bearing for excessive play. Refer to Rear Suspension for specifications. Is the left rear wheel bearing play out of specifications? | -- | Go to Step 11 | Go to Step 4
4 |

1. Turn the ignition switch to the LOCK position.
2. Raise and suitably support vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Remove the right rear wheel speed sensor. Refer to Rear Wheel Speed Sensor Replacement .
4. Inspect the right rear wheel speed sensor and its pickup surface area for physical damage.

Does the right rear wheel speed sensor have signs of any physical damage?

--

Go to Step 12

Go to Step 5

5 | Inspect the right rear wheel speed sensor reluctor wheel for physical damage. Does the right rear wheel speed sensor reluctor wheel have signs of physical damage? | -- | Go to Step 13 | Go to Step 6
6 |

1. Disconnect the Electronic Brake Control Module (EBCM) electrical connector.
2. Use J 39200 (DMM) in order to measure the resistance between the EBCM electrical connector terminal 15 and terminal 16 (harness side).

Is the resistance within the specified range?

1120-2520 ohms

Go to Step 7

Go to Step 8

7 |

1. Reinstall the right rear wheel speed sensor.
2. Tighten the right rear wheel speed sensor bolt to 7.8 N·m (69 lb in).
3. Select the A/C VOLTAGE scale on J 39200 (DMM).
4. Leave J 39200 (DMM) still connected to the EBCM electrical connector terminal 15 and terminal 16 (harness side).
5. Spin the right rear wheel by hand while observing voltage reading on J 39200 (DMM).

Is the voltage equal to or greater than the specified voltage?

100 mV

Go to Step 9

Go to Step 12

8 |

1. Remove the rear seatback. Refer to Rear Seat Back Replacement in Seats.
2. Disconnect the right rear wheel speed sensor.
3. Use J 39200 in order to measure the resistance between the EBCM electrical connector terminal 15 and terminal 16 (harness side).

Is the resistance equal to the specified value?

OL

(Infinite)

Go to Step 12

Go to Step 14

9 |

1. Inspect the EBCM electrical connector for signs of damage, poor terminal contact, or terminal corrosion that would result in a short between the EBCM electrical connector terminal 15 and terminal 16.
2. Inspect the right rear wheel speed sensor electrical connector for signs of damage, poor terminal contact, or terminal corrosion.

Did you detect signs of poor terminal contact, corrosion, or damaged terminals?

--

Go to Step 15

Go to Step 10

10 |

1. Reconnect the EBCM electrical connector.
2. Reconnect the right rear wheel speed sensor electrical connector.
3. Disconnect the scan tool from the DLC.
4. Test drive the vehicle at 24 km/h (15 mph) for 30 seconds.
5. Stop the vehicle.
6. Connect a scan tool to the OBD2 Data Link Connector (DLC).
7. Select Diagnostic Trouble Codes (DTCs) on the scan tool.
8. Select DTC Information on the scan tool.
9. Select Current DTC on the scan tool.

Does DTC C0051 set as a current DTC?

--

Go to Step 16

Go to Diagnostic System Check - ABS

11 | Repair the excessive right rear wheel bearing play. Refer to Rear Wheel Bearing and Hub Replacement in Rear Suspension for service procedure. Is the repair complete? | -- | Go to Step 17 | --
12 | Replace the right rear wheel speed sensor. Refer to Rear Wheel Speed Sensor Replacement . Is the repair complete? | -- | Go to Step 17 | --
13 | Replace the right rear wheel hub and bearing. Refer to Rear Wheel Bearing and Hub Replacement in Rear Suspension. Is the repair complete? | -- | Go to Step 17 | --
14 | Repair the damaged wiring harness that caused the short between the YEL and BRN wires. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 17 | --
15 | Repair or replace wiring, terminals, or connectors that exhibit signs of damage as necessary. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 17 | --
16 | Replace the brake pressure modulator valve assembly. Refer to Brake Pressure Modulator Valve Assembly Replacement . Is the action complete? | -- | Go to Diagnostic System Check - ABS | --
17 |

1. Ensure the EBCM and the right rear wheel speed sensor electrical connectors are connected.
2. Disconnect the scan tool from the DLC.
3. Test drive Vehicle at 24 km/h (15 mph) for 30 seconds.
4. Stop the vehicle.

Is the ABS Warning Indicator ON?

--

Go to Diagnostic System Check - ABS

--