Antilock Brakes / Traction Control Systems: Service Precautions

NOTE: On Vehicles Equipped With Airbag, Disarm Airbag As Outlined Under MAINTENANCE PROCEDURE/AIRBAG DEACTIVATION Before Any Diagnosis, Testing, Troubleshooting Or Repairs Are Performed. After All Diagnosis, Testing, Troubleshooting Or Repair Have Been Completed, Rearm Airbag As Outlined Under MAINTENANCE PROCEDURE/AIRBAG ACTIVATION.

Some of the following procedures require that hydraulic lines, hoses and fittings be disconnected for inspection of testing. This Teves brake system uses a hydraulic accumulator which, when completely charged, contains brake fluid under high pressure. Before disconnecting any hydraulic lines, hoses or fittings, ensure the accumulator is completely depressurized as described further on. Failure to depressurize the hydraulic accumulator may result in personal injury and/or damage to painted surfaces and/or the vehicle.
Certain components in the system are not intended to be serviced individually. Do not attempt to remove or disconnect certain system components, such as the hydraulic accumulator or valve block. Only those components with removal procedures should be serviced.
Torque bolts attaching the brake caliper mounting bracket to the front and rear knuckles must be replaced any time they are removed or become loose. Tightening or loosening the torque bolts, which use encapsulated thread locking compound, is not recommended. Failure to replace the brake caliper mounting bracket torque bolts, after they have been loosened or removed, may result in loosening of the caliper to knuckle assembly, causing reduced vehicle braking ability.

COMPUTER SYSTEM SERVICE PRECAUTIONS

This Teves anti-lock brake system interfaces directly with the Electronic Brake Control Module (EBCM) and on some models, the Body Computer Module (BCM). These modules are designed to withstand normal current draws associated with vehicle operation. However, care must be taken to avoid overloading any of the EBCM or BCM circuits. During testing of opens or shorts, do not ground or apply voltage to any of the circuits unless instructed to do so by the appropriate diagnostic procedure. These circuits should only be tested with a high impedance multimeter (J-35029-A or equivalent), or special tools described further on. Power should never be removed or applied to any control module with the ignition switch in the On position. Before removing or connecting battery cables, fuses, or connectors, always turn the ignition switch to the Off position.

GENERAL SERVICE PRECAUTIONS

If welding work is to be performed on the vehicle using an electric arc welder, the EBCM and valve block connectors should be disconnected before the welding operation begins. The EBCM and valve block connectors should never be connected or disconnected with the ignition switch in the On position. Some components of the anti-lock brake system are not serviceable separately and must be replaced as assemblies.