The anti-lock braking system (ABS) and also Traction Control systems in your Grand Prix both usage the ABS wheel-speed sensors and also modulator valve assembly to control wheel slip. The ABS system monitors the wheel-rate sensors and relieves brake pressure on a wheel that it senses is nearing lock-up. The Traction Control device monitors the same wheel-speed sensor and also applies brake pressure to any wheel it senses over increasing. Diagnosis of these systems is achieved making use of a sdeserve to tool and also the car"s on-board computer diagnostics feature.

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Check the tires for appropriate wheel dimension and examine the liquid level in master cylinder. Imappropriate tire size, such as two different sizes, will reason the wheels to rotate at different speeds and also might collection a false code once the computer senses this as potential wheel lock-up. Low liquid level in the brake grasp cylinder will lead to shutdown of the ABS and Tractivity Control system to proccasion advent of air right into the brake mechanism.


Turn the ignition crucial off and also insert the scan tool"s connector into the vehicle"s diagnostic connector. The diagnostic connector in OBD-II equipped Grand Prix is located under the driver"s side of the dash close to the steering column. Turn the ignition crucial on and retrieve trouble codes according to the instructions supplied with the scan tool. In most cases you will certainly choose "Read Codes" from the onscreen menu or push the "Read" switch on the front of the sdeserve to tool to retrieve codes. Go to step 2 if the code suggests a wheel rate sensor fault or action five if the codes shows a solenoid fault.


Select "Data" from the ondisplay screen food selection and scroll with the list till wheel rate sensor information is displayed on the display screen. Test drive the auto while surveillance the wheel rate signals, suggested by the fault code, on the shave the right to tool. If the wheel rate signal is different from the remaining wheel rate signals, test the resistance of the sensor.


Unplug the faulty wheel rate sensor, located on the back of the wheel bearing and also hub assembly at each wheel in the Grand Prix and test the resistance of the sensor utilizing your digital volt/ohm meter collection to check out resistance. The resistance of a good wheel rate sensor will certainly be1k ohms +/- 10 percent. Rearea the sensor if the meter shows 0 ohms, unlimited ohms, or the resistance is not 1k ohms +/- 10 percent.

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Check foffers in the fusage block under the dash and under the hood. The foffers for the ABS and also Tractivity Control devices are noted on the body of the fuse blocks. Relocation any type of faulty foffers before continuing through the tests. Unplug the modulator valve assembly situated on the driver"s side of the passenger compartment close to the grasp cylinder and test the resistance of solenoids using you digital volt/ohm meter. Rearea the modulator valve assembly if 0 ohms or infinite resistance are measured at the assembly.