For 1990-2009 cars
ABS Components
Cell 44: Stoplamp/BTSI Switch, Inlet/Outlet Solenoid Valves, and Wheel Speed Sensors
Handling ESD Sensitive Parts Notice

### Circuit Description

The wheel speed sensor creates an AC voltage as each wheel turns. The frequency of the voltage is proportional to the wheel speed.

The voltage is magnetically induced. The voltage is caused by a toothed sensor ring (mounted on the drive axle) which passes the stationary pickup coil of the wheel speed sensor.

The EBCM/EBTCM uses the wheel speed sensor signal to calculate the following values:

• | The vehicle reference speeds

• | The speed of each wheel

• | The acceleration

• | The slip values

Use these values in order to determine when antilock or traction control (when equipped) is required.

### Conditions for Setting the DTC

The DTC C1233 sets under the following circumstances:

• | The EBCM/EBTCM does not see a wheel speed sensor signal

• | The EBCM/EBTCM determines that continuity exists in the circuit

These circumstances can result from the following conditions:

• | A dislodged wheel speed sensor

• | A missing toothed sensor ring (front)

• | A defective hub and bearing assembly (rear)

### Action Taken When the DTC Sets

The following actions will be taken when the DTC sets:

• | A malfunction DTC is stored.

• | The ABS is disabled.

• | The ANTILOCK indicator lamp is turned ON.

### Conditions for Clearing the DTC

The DTC will be cleared under following conditions:

• | Conditions for the malfunction are no longer present. Use the scan tool clear DTCs function.

• | 100 ignition switch key cycles have passed with no malfunctions detected

### Diagnostic Aids

One of the following conditions may cause an intermittent malfunction:

• | A poor connection

• | A rubbed through wire insulation

• | A wire that is broken inside the insulation

Inspect any suspect circuitry 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

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

1. Inspect the right rear wheel speed sensor wiring and connectors for damage.
2. Inspect the right rear wheel speed sensor for looseness or damage.

Does the sensor or the wiring have any physical damage?

--

Go to Step 7

Go to Step 3

3 |

1. Disconnect the right rear wheel speed sensor directly at the sensor.
2. Use the J 39200 in order to measure the resistance between terminal A and terminal B of the right rear wheel speed sensor.

Is the resistance within the specified range?

850-1350 ohms

Go to Step 4

Go to Step 8

4 | Spin the wheel by hand as quickly as possible while monitoring the AC output. Is the AC voltage greater than the specified value? | 100 mV | Go to Step 5 | Go to Step 8
5 |

1. Disconnect the EBCM/EBTCM harness connector.
2. Use the J 39200 in order to measure the resistance between terminal 27 and terminal 45.

Is the resistance within the specified range?

OL (Infinite)

Go to Step 6

Go to Step 9

6 |

1. Reconnect all of the connectors.
2. Test drive the vehicle above 24 km/h (15 mph) for at least 30 seconds while monitoring the scan tool for ABS/TCS DTCs.

Does the DTC C1233 reset?

--

Go to Step 10

Go to Diagnostic System Check

7 |

1. Repair or replace all of the damaged components as necessary. Refer to Wiring Repairs in Wiring Systems or Rear Wheel Bearing and Hub Replacement in Rear Suspension.
2. Drive the vehicle above 24 km/h (15 mph) for at least 30 seconds while monitoring a scan tool in order to ensure that the DTC does not reset.

Does the DTC C1233 reset?

--

Go to Step 3

Go to Diagnostic System Check

8 | Replace the right rear wheel speed sensor. Refer to Rear Wheel Bearing and Hub Replacement in Rear Suspension. Is the repair complete? | -- | Go to Step 11 | --
9 | Repair the short between CKT 883 and CKT 882. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 11 | --
10 | Replace the EBCM/EBTCM. Refer to Electronic Brake and Traction Control Module Replacement . Is the repair complete? | -- | Go to Step 11 | --
11 | Test drive the vehicle above 24 km/h (15 mph) for at least 30 seconds while monitoring the scan tool for ABS/TCS DTCs. Does the DTC C1233 reset? | -- | Go to Step 2 | Go to Diagnostic System Check