| Table 1: | WSS Temperature vs. Sensor Resistance |
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
| • | No output signal from the right front wheel speed sensor for 1.0 second |
| • | Excessive right front wheel speed sensor resistance for 1.0 second |
Action Taken When the DTC Sets
| • | The ABS indicator lamp turns on |
| • | The ABS disables |
DTC C0221 is a Condition Latched DTC, which indicates that the above actions remain true only as long as the condition persists.
Conditions for Clearing the DTC
| • | Repair the conditions responsible for setting the DTC |
| • | Use the Scan Tool Clear DTCs function |
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:
- Spray the suspected area with a 5% salt water solution (two teaspoons of salt to 12 oz. of water)
- 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. Refer to Wheel Speed Sensor Replacement .
Resistance of the wheel speed sensor will increase with an increase in sensor temperature. Refer to the following table for temperature/resistance values.
°C | °F | Ohms |
|---|---|---|
Temperature vs Resistance Values (Approximate) | ||
-40 to 4 | -40 to 40 | 1500-2500 |
5 to 43 | 41 to 110 | 1500-2500 |
44 to 93 | 111 to 200 | 1500-2500 |
94 to 150 | 201 to 302 | 1500-2500 |
Test Description
The numbers below refer to the steps in the diagnostic table:
-
This step checks the resistance of the right front wheel speed sensor circuit.
-
This step checks for continuity in the right front wheel speed sensor harness.
-
This step checks the resistance of the right front wheel speed sensor.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Diagnostic System Check | |
2 |
Is the resistance measurement within the specified range? (Refer to the table on the facing page for applicable sensor resistance values. The values in this table are for the resistance of the sensor, not the air temperature.) | -- | ||
3 |
Is the resistance measurement within the specified range? | 0-2 ohms | ||
4 | Using a J 39200 , measure the resisatnce between teminals A and B of the right front wheel speed sensor connector. Is the resistance measurement within the specified range? (Refer to the table on the facing page for applicable sensor resistance values. The values in this table are for the resistance of the sensor, not the air temperature.) | -- | ||
5 | Inspect the 4-way EBCM harness connector for poor terminal contact or corrosion. Does damage or corrosion exist? | -- | ||
6 |
Does the DTC set as a current DTC? | -- | ||
7 |
Is the repair complete? | -- | Go to Diagnostic System Check | -- |
8 | Make necessary repairs to the 4-way EBCM harness connector. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
9 | Replace the EBCM. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
10 | Repair the open or high resistance in CKT 833 or CKT 872. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
11 | Replace the wheel speed sensor. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
