C0223

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CIRCUIT DESCRIPTION
The wheel speed sensor coil emits an electromagnetic field. A toothed ring on the wheel passes by the wheel speed sensor and disrupts this electromagnetic field. The disruption in the field causes the wheel speed sensor to produce a sinusoidal (AC) voltage signal. The frequency and amplitude of the sinusoidal (AC) voltage signal are proportional to the speed of the wheel. The amplitude of the wheel speed signal is also directly related to the distance between the wheel speed sensor coil and the toothed ring. This distance is referred to as the air gap.

CONDITIONS FOR SETTING THE DTC
The wheel speed signal for all sensors is above 19 km/h (12 mph) with brake released, or 32 km/h (20 mph) with brake applied, with a sudden loss of one signal for 15 ms.

ACTION TAKEN WHEN THE DTC SETS
- The ABS indicator lamp turns on
- The ABS disables DTC C0223 is Condition Latched for the first two occurrences, Ignition Latched thereafter.

DTC C0223 is a DRP non critical malfunction. If another front WSS DTC sets before this DTC is investigated and cleared, this will become a DRP Critical malfunction and the BRAKE indicator lamp will also turn on.

CONDITIONS FOR CLEARING THE DTC
- Repair the conditions responsible for setting the DTC
- Use the Scan Tool Clear DTCs function
- A Condition Latched DTC may exist momentarily, or constantly. In either case, the DTC will be stored in the EBCM memory until it is repaired, and/or the DTC is cleared. After the DTC is repaired and/or cleared and the ignition is turned to ON, the ABS lamp will remain lit until the EBCM completes a power-up self test. This test concludes when the vehicle has reached a speed of greater than 13 km/h (8 mph) and the wheel speed inputs have been checked by the EBCM.

DIAGNOSTIC AIDS
Any of the following conditions may cause an intermittent malfunction:
- A poor connection
- Wire insulation that is rubbed through
- A wire breaks inside the insulation

Thoroughly check any circuitry that is suspected of 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

If the customer says that the ABS indicator lamp is on only during humid conditions such as rain, snow, or vehicle wash, then thoroughly inspect all wheel speed sensor circuits for signs of water intrusion. Use the following procedure:
1. Spray the suspected area with a 5% salt water solution (two teaspoons of salt to 12 oz. of water)
2. Drive the vehicle above 24 km/h (15 mph) for at least 30 seconds

If the DTC returns, replace the suspected harness. When inspecting a wheel speed sensor, inspect the sensor terminals and the harness connector for corrosion. If evidence of corrosion exists, then replace the wheel speed sensor.

WSS Temperature vs. Sensor Resistance:

Resistance of the wheel speed sensor will increase with an increase in sensor temperature.

TEST DESCRIPTION
The numbers below refer to the steps in the diagnostic table:
3. This step checks for the proper wheel speed sensor voltage output.
4. This step uses the wheel speed sensor resistance check to help isolate an intermittent connection.
5. This step checks to see if the DTC will set again even after the initial checks were made.
6. This step checks for proper wheel speed sensor resistance.
7. This step checks for proper mounting and orientation of the wheel speed sensor.