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 left rear wheel speed is less than 6 km/h (4 mph) |
| • | All other wheel speeds are greater than 13 km/h (8 mph) |
| • | No unexpected wheel acceleration/deceleration. Anything that keeps the left rear wheel speed sensor low while the vehicle is moving above 13 km/h (8 mph). |
Action Taken When the DTC Sets
| • | The ABS indicator lamp turns on |
| • | The ABS disables |
DTC C0236 is an Ignition Latched DTC, which indicates that the above actions remain true until the ignition is turned to OFF (even if the cause of the DTC is intermittent).
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 Rear Wheel Speed Sensor Replacement .
Test Description
The numbers below refer to the steps in the diagnostic table:
-
This step checks for the resistance of the left rear wheel speed sensor.
-
This step checks the voltage output of the left rear wheel speed sensor.
-
This step checks for a short in the wiring between the wheel speed sensor circuits.
-
This step checks for a short to ground in the left rear wheel speed sensor circuits.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | |
2 |
Is there evidence of physical damage? | -- | Go to Step 8 | Go to Step 3 |
Is the resistance measurement within the specified range? | 1500-2500 ohms | Go to Step 4 | Go to Step 9 | |
Is the voltage measured equal to or greater than the specified value? | 100 mV | Go to Step 5 | Go to Step 9 | |
Is the resistance measurement equal to the specified value? | OL | Go to Step 6 | Go to Step 11 | |
Is the resistance measurement equal to the specified value? | OL | Go to Step 7 | Go to Step 12 | |
7 |
Inspect CKT 884 and CKT 885 for damage that could result in a shorted circuit. Repair any evident damage. Replace the terminals if poor contact or corrosion exists. Does DTC C0236 set as a current DTC? | -- | Go to Step 10 | Go to Diagnostic Aids |
8 | Make the necessary repairs. Is the repair complete? | -- | -- | |
9 | Replace the left rear wheel speed sensor. Refer to Rear Wheel Speed Sensor Replacement . Is the repair complete? | -- | -- | |
10 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | -- | |
11 | Repair the short between CKT 884 and CKT 885. Refer to Wiring Repairs . Is the repair complete? | -- | -- | |
12 | Repair short to ground in CKT 884 or CKT 885. Refer to Wiring Repairs . Is the repair complete? | -- | -- |
