Otc C0055 Rear Wheel Speed Circuit Malfunction - GMC chervolet camaro 1999 Service Manual

5-156 Antilock Brake System Brakes
OTC C0055 Rear Wheel Speed Circuit Malfunction
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C200D
Circuit Description
The speed sensor used on this vehicle is a single
point magnetic pickup. This sensor produces an AC
signal that the EBCM uses the frequency from to
calculate the wheel speed.
Conditions for Setting the DTC
The DTC can be set any time the ignition is in the
RUN position and the EBCM detects an open or
a short to voltage.
Action Taken When the DTC Sets
• A malfunction DTC stores.
• The 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 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
A15
A14 C200A
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- 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
ABS indicator is on only during moist
environmental conditions (rain, snow, vehicle
wash), inspect all the wheel speed sensor circuitry
for signs of water intrusion. If the OTC 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 Electrical
Diagnosis for further diagnosis.