| Table 1: | WSS Temperature vs. Sensor Resistance (S-Pickup only) |
| Table 2: | WSS Temperature vs. Sensor Resistance (S-Utility and T-Truck) |
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 left front wheel speed sensor for 1.0 second |
| • | Excessive left 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 C0225 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 |
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 tables for temperature/resistance values.
°C | °F | Ohms |
|---|---|---|
Temperature vs Resistance Values (Approximate) | ||
-40 to 4 | -40 to 40 | 3915 to 5820 |
5 to 43 | 41 to 110 | 4760 to 6800 |
44 to 93 | 111 to 200 | 5560 to 8040 |
94 to 150 | 201 to 302 | 6600 to 9406 |
°C | °F | Ohms |
|---|---|---|
Temperature vs Resistance Values (Approximate) | ||
-40 to 4 | -40 to 40 | 920 to 1440 |
5 to 43 | 41 to 110 | 1125 to 1700 |
44 to 93 | 111 to 200 | 1305 to 2000 |
94 to 150 | 201 to 302 | 1530 to 2310 |
Test Description
The numbers below refer to the steps in the diagnostic table:
-
This step checks the resistance of the left front wheel speed sensor circuit.
-
This step checks for continuity in the left front wheel speed sensor harness.
-
This step checks the resistance of the left front wheel speed sensor.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to A Diagnostic System Check | |
Is the resistance measurement within the specified range? (Refer to the WSS Temperature vs. Sensor Resistance tables for applicable sensor resistance values. The values in these tables are for the temperature of the sensor, not the air temperature.) | -- | |||
Is the resistance measurement within the specified range? | 0-2 ohms | |||
Using a J 39200 , measure the resistance between terminals A and B of the left front wheel speed sensor connector. Is the resistance measurement within the specified range? (Refer to the WSS Temperature vs. Sensor Resistance tables for applicable sensor resistance values. The values in these tables are for the temperature 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 | Malfunction is intermittent.
Refer to Diagnostic Aids for more information. Is the repair complete? | -- | Go to A Diagnostic System Check | -- |
8 | Make necessary repairs to the 4-way EBCM harness connector. Is the repair complete? | -- | Go to A Diagnostic System Check | -- |
9 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | Go to A Diagnostic System Check | -- |
10 | Repair the open or high resistance in CKT 830 or CKT 873. Is the repair complete? | -- | Go to A Diagnostic System Check | -- |
11 | Replace the wheel speed sensor. Refer to Wheel Speed Sensor Replacement . Is the repair complete? | -- | Go to A Diagnostic System Check | -- |
