C0055

Part 1 Of 2:

Part 2 Of 2:

CIRCUIT DESCRIPTION
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the Electronic Brake Control Module (EBCM) uses the frequency from to calculate the wheel speed.

CONDITIONS FOR SETTING THE DTC
The Diagnostic Trouble Code (DTC) can be set any time the ignition is in the RUN position and the Electronic Brake Control Module (EBCM) detects an open or a short to voltage.

ACTION TAKEN WHEN THE DTC SETS
^ A malfunction Diagnostic Trouble Code (DTC) stores.
^ The Antilock Brake System (ABS) disables.
^ The amber ABS indicator turns on.
^ The Red BRAKE Warning indicator turns on.

CONDITIONS FOR CLEARING THE DTC
^ The condition responsible for setting the Diagnostic Trouble Code (DTC) no longer exists and the Scan tool Clear DTCs function is used.
^ 100 ignition cycles pass with no DTC(s) detected.

DIAGNOSTIC AIDS
^ It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
^ Thoroughly inspect any circuitry that may be causing the 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

^ The following conditions may cause an intermittent malfunction:
- A poor connection
- Rubbed-through wire insulation
- A broken wire inside the insulation

^ If the customer's comments reflect that the amber Antilock Brake System (ABS) indicator is on only during moist environmental conditions (rain, snow, vehicle wash), inspect all the Wheel Speed Sensor (WSS) circuitry for signs of water intrusion. If the Diagnostic Trouble Code (DTC) is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure:
1. Spray the suspected area with a five percent saltwater solution. Add two teaspoons of salt to twelve ounces of water to make a five percent saltwater solution.
2. Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 40 Km/h (25 mph) for at least 30 seconds.
3. If the DTC returns, replace the suspected harness.

^ If an intermittent malfunction exists refer to Troubleshooting Procedures Cell 4 in Diagnostic Aids for further diagnosis.

REAR WHEEL SPEED SENSOR RESISTANCE
The table shown contains resistance values for the rear Wheel Speed Sensors (WSS) at varying sensor temperatures for use in diagnosis. The values are approximate and should be used as a guideline for diagnosis.





DTC C0055 REAR WHEEL SPEED CIRCUIT MALFUNCTION

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
6. This step checks for an open in the Wheel Speed Sensor (WSS) or WSS CKT.
13. Checks for a short to voltage in the WSS CKT.
15. Checks for a short to voltage in the WSS CKT.