ParkAvenue 1997-1999

Teves Mark IV-G & IV System

Print

Anti-Lock Diode



Location

The anti-lock diode is taped to the wiring harness near the EBCM, under the dashboard.

Bleeding The ABS System



Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

On these vehicles, the bleeding procedure is the same as for those vehicles not equipped with ABS. Please refer to the bleeding procedure, located earlier in this section.

Electronic Brake Control Module (EBCM)



Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

The electronic brake control module is located on the right side of the vehicle and positioned under the right sound insulator panel. In order to gain access to electronic brake control module, it will be necessary to first remove the trim panel.

Removal & Installation

On vehicles with the Traction Control System (TCS), the EBCM is referred to as the EBTCM.

  1. Make sure the ignition is in the OFF position.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the sound insulators necessary for access to the module.
  6.  
  7. If necessary, remove the floor outlet.
  8.  
  9. If equipped, unfasten the EBCM/EBTCM retaining bolt.
  10.  
  11. Slide the EBCM from the mounting bracket, toward the accelerator pedal.
  12.  
  13. Detach the EBCM electrical connector, then remove the module from the vehicle.
  14.  



Click image to see an enlarged view

Fig. Exploded view of the EBCM mounting - 1991 vehicles

  1. For 1991 vehicles, to remove the EBCM bracket, perform the following:
    1. Unfasten the screws and remove the ALDL.
    2.  
    3. Remove the bracket by lifting upward.

      Click image to see an enlarged view

      Fig. EBCM bracket mounting - 1991 vehicles

    4.  

  2.  
  3. For 1992-93 vehicles, to remove the EBCM/EBTCM bracket, perform the following:
    1. Unfasten the retaining nuts, remove the deflector, then remove the bracket.
    2.  

  4.  



Click image to see an enlarged view

Fig. Exploded view of the EBCM/EBTCM and mounting bracket - 1992-93 vehicles

To install:

  1. For 1992-93 vehicles, to install the EBCM/EBTCM bracket, perform the following:
    1. Position the bracket, install the deflector and secure with the retaining nuts. Tighten the nuts to 89 inch lbs. (10 Nm).
    2.  

  2.  
  3. On 1991 vehicles, if the bracket was removed, perform the following:
    1. Position the bracket to the heater outlet.
    2.  
    3. Install the ALDL.
    4.  
    5. Install the retaining screws and tighten to 13 inch lbs. (1.5 Nm).
    6.  

  4.  
  5. Attach the EBCM electrical connector, then slide the module assembly into the bracket.
  6.  
  7. If equipped, install the retaining bolt and tighten to 42 inch lbs. (4.7 Nm).
  8.  
  9. Install any sound insulators that were removed.
  10.  
  11. Connect the negative battery cable.
  12.  

General Description



Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

The Teves Mark IV ABS system is used on 1991-93 vehicles covered by this manual. The system allows individual modulation of braking force at each wheel as well as providing traction control at the drive wheels if the vehicle is so equipped. The ABS system employs a conventional diagonally-split braking system and additional ABS components. The system allows the operator to maintain directional control during heavy braking situations by preventing locked-wheel skidding.

On vehicles equipped with the Traction Control System (TCS), wheel spin at the drive wheels is reduced by selective application of the wheel brakes if vehicle speed is below 25 mph (40 km/h). The TCS system is designed to improve traction on loose or wet surfaces and aid in getting the vehicle moving from rest.



Click image to see an enlarged view

Fig. Teves Mark IV Anti-lock Brake System (ABS) components - 1991-93 vehicles

System Components
Electronic Brake Control Module (EBCM)

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

Located on the inner firewall, the EBCM is a solid-state computer which monitors the speed of each wheel as well as the electrical status of the PMV assembly. Once wheel lock or wheel slip (with TCS) is detected, the EBCM operates the inlet and outlet valves in the PMV to control wheel speed. The valves can be cycled very rapidly, allowing control to be maintained in all operating situations.

The EBCM will disable either the TCS or ABS if a fault is detected. In most cases, the system will remain disabled for the remainder of the driving cycle, even if the fault self-corrects before the next key-on cycle. If either low system voltage is detected at the EBCM or low brake fluid level is detected at the PMV, the systems(s) will be disabled until the condition is corrected. Once the sensors indicate normal voltage or fluid level, the system(s) are enabled, even if the vehicle has not been shut off and restarted.

If the control unit detects an electrical fault, it will disable the TCS and/or ABS system immediately and illuminate the appropriate dash warning lamp to advise the operator. A fault code will usually be set in memory. Although it is possible for just the TCS system to be disabled, any fault in the ABS system will also cause the TCS system to be disabled.

The fault codes may be retrieved when the EBCM is placed into the diagnostic mode. A bi-directional hand scanner is required to retrieve or clear stored codes; no warning lamp flash outputs are used.

Fluid Level Sensors

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

The brake fluid reservoirs on both the master cylinder and pressure modulator valve contain fluid level sensors. If the master cylinder reservoir becomes low on fluid, the red BRAKE warning lamp will be lit, signaling a potential system hazard. If the fluid level in the PMV reservoir becomes too low, the amber ANTI-LOCK warning lamp is lit and the ABS/TCS system disabled until the level returns to minimum.

Pressure Modulator Valve (Pmv) Assembly

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

The assembly consists of the pump and motor, the valve body and the fluid reservoir. The reservoir provides fluid to the pump while the pump circulates the fluid to the master cylinder and maintains pedal height. The valve block contains the inlet and outlet valves for each wheel circuit.

When equipped with traction control, the PMV contains the isolation valves used to block pressure in the master cylinder and rear wheel circuits.

The PMV is not serviceable except for replacement of the reservoir.

Proportioner Valves

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

Each rear wheel circuit contains a proportioning valve to limit brake pressure to the non-driven wheels. These valves improve front-to-rear brake balance during normal braking.

TCC/ABS Brake Switch

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

This normally closed switch is integral to the normal electrical/vacuum-release brake switch. It monitors position of the brake pedal, opening when the pedal exceeds 40 percent of total travel. The EBCM then turns on the pump in the pressure modulator valve assembly, circulating fluid and forcing the pedal upward until the switch closes.

Warning Lamps

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

Certain models equipped with traction control may cause a pilot lamp to light or a message to be displayed when the system is engaged. These signals are a convenience to the operator but are not system warning lamps.

Anti-Lock

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

The amber ANTI-LOCK dashboard warning lamp is lit when the EBCM detects a fault within the ABS system. When this lamp is lit, the ABS system is disabled. If only the ANTI-LOCK lamp is lit, full power-assisted braking is available without the added benefit of the anti-lock system.



Click image to see an enlarged view

Fig. Normal functions of the ABS/TCS dashboard warning lamps

Brake

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

The red BRAKE warning lamp in the instrument panel illuminates to alert the operator of conditions in the conventional braking system which may affect braking or vehicle operation. The lamp will illuminate when the parking brake is applied, the brake fluid in the master cylinder reservoir is low or when the ignition is switched to START , allowing the function of the bulb to be confirmed. Illumination of this lamp during vehicle operation signals a potentially hazardous condition within the brake system.

Traction/Traction Off

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

This warning lamp applies specifically to the traction control system. It will light if the EBCM detects a problem specific to the TCS or if the operator has switched the system off manually.

On vehicles equipped with traction control, the EBCM is programmed to prevent brake overheating. During heavy braking conditions, if traction control mode is entered and the controller determines that the brakes are too hot to function properly, the TCS is disabled and the warning lamp is lit. After a period of time, usually 15-20 minutes, the system is enabled and the warning lamp extinguished. This protective behavior is normal operation and should not be mistaken for an intermittent system failure.

Additionally, the EBCM monitors the signal from the transaxle temperature switch. If transaxle temperature exceeds approximately 320°F (160°C), the controller will disable the traction system, allowing both the brakes and the transaxle to cool. When the temperature switch closes again, at approximately 300°F (140°C), the EBCM will keep the system disabled for an additional 3-5 minutes to allow further cooling. The dash warning lamp will be illuminated during the period of disablement.

Wheel Speed Sensors

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

A wheel speed sensor at each wheel transmits speed information to the EBCM by generating a small AC voltage relative to the wheel speed. The voltage is generated by magnetic induction caused by passing a toothed sensor ring past a stationary sensor. the signals are transmitted through a pair of wires which are shielded against interference. The EBCM then calculates wheel speed for each wheel based on the frequency of the AC signal received from the sensor.

System Operation

Braking is performed by the conventional brake system until the Electronic Brake Control Module (EBCM) detects a wheel beginning to lock, or the brake pedal has traveled beyond a specified limit. The EBCM will then command the system into anti-lock mode.

Electric signals are received by the EBCM from each wheel speed sensor. By comparing these signals to each other and to pre-programmed values, the EBCM can determine that one or more wheels is approaching lock-up. The EBCM activates the Pressure Modulator Valve (PMV) to control fluid pressure to the wheels. The PMV assembly has 2 valves per hydraulic circuit; the EBCM operates these valves electrically to control brake pressure. The valves may be placed into 3 modes: pressure increase, pressure reduce or pressure hold. By switching rapidly between these 3 modes, the EBCM can reduce pressure at the locking wheel, slow the most rapid wheel to the average or maintain the wheels just below the point of lock-up.

During the pressure increase mode, the inlet valve within the PMV is open, allowed to enter the particular hydraulic circuit. As this mode cycles, pressure and fluid is reduced within the master cylinder, causing the brake pedal to drop nearer the floor. When the pedal travel exceeds a pre-determined level, the EBCM will activate the PMV pump motor. Pump pressure is applied to the wheel circuit(s) in need and/or the master cylinder hydraulic circuits. With pressure applied to the master cylinder hydraulic circuits, the pedal will rise until the brake travel switch is de-activated, switching the pump off.

During vehicle operation, the EBCM performs a series of self-tests, checking both electronic and hydraulic systems for vaults. If detectable problems exist, the EBCM will set a fault code and/or illuminate the ANTI-LOCK dash warning lamp. The ANTI-LOCK warning lamp is in addition to the normal BRAKE warning lamp which warns of problems in the conventional brake system.

Traction Control System (Tcs)

The traction control system is additional to the ABS system and is not found on all vehicles with ABS. With traction control, brake pressure is increased to reduce wheel spin; with ABS, line pressure is reduced to allow greater wheel spin. The EBCM monitors the speed of the drive wheels through the wheel speed sensors; if wheel slip is detected below 25 mph with the brakes not applied, the EBCM enters the traction control mode.

Once in traction control mode, the EBCM commands two isolation valves in the PMV into operation. The isolation valves close to separate the non-driven wheels and the master cylinder circuits from the drive wheels. Once isolated, brake fluid pressure may be applied to the drive wheels without affecting the other circuits. The EBCM turns on the PMV pump motor and begins cycling the inlet and outlet valves to slow the slipping wheel(s).

Since the pump motor supplies more fluid than required, two pressure relief valves allow excess fluid to return to the master cylinder reservoir.

Vehicles equipped with TCS are also be equipped with a manual switch to disable the traction system. When the switch is engaged, canceling system operation, a TRACTION OFF dashboard warning lamp will be illuminated. Some vehicles also have indicators showing that the TCS is engaged, either by lighting a dashboard lamp or displaying a TRACTION ENGAGED message.

Pmv Fluid Level Sensor



Removal & Installation

The fluid level sensor is integrated with the PMV reservoir. If the sensor fails, the reservoir must be replaced.

Pmv Reservoir



Removal & Installation

The reservoir with the fluid level sensor is the only replaceable component on the PMV assembly. It may be replaced without removing the PMV assembly from the vehicle.

  1. Disconnect the electrical connector from the reservoir.
  2.  
  3. Loosen or reposition the clamp on the hose at the PMV reservoir.
  4.  
  5. Disconnect the hose from the reservoir. Catch escaping fluid in a clean container; plug the hose with a 5 / 8 inch (15.5mm) diameter plug.
  6.  
  7. Carefully pry or force the reservoir free of its rubber mounts on the PMV assembly.
  8.  



Click image to see an enlarged view

Fig. Removing the Pressure Modulator Valve (PMV) reservoir

  1. Remove and discard the rubber seals from the PMV; taking care to note the orientation or placement of the seals.
  2.  

To install:

  1. Lubricate new seals with clean brake fluid, then fit the seals to the PMV assembly. Make certain the seals are correctly installed.
  2.  
  3. Clean the reservoir and ports with denatured alcohol. Install the reservoir onto the PMV assembly.
  4.  
  5. Connect the hose to the reservoir and secure the clamp.
  6.  
  7. Attach the reservoir wiring connector.
  8.  
  9. Fill the reservoir with clean, fresh brake fluid.
  10.  
  11. Bleed the brake system.
  12.  
  13. Clean any spilled brake fluid from the PMV assembly and surrounding area to prevent damage to other components or paint work.
  14.  

Pressure Modulator Valve (Pmv) Assembly



Removal & Installation
  1. Remove the air cleaner assembly.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Label and disconnect the following wiring connectors from the PMV assembly:
    1. Fluid level switch
    2.  
    3. Pump motor
    4.  
    5. Valve block
    6.  

  6.  
  7. Loosen or reposition the clamp on the hose at the PMV reservoir.
  8.  
  9. Disconnect the hose from the reservoir. Catch escaping fluid in a clean container, then plug the hose with a 5 / 8 inch (15.5mm) diameter plug.
  10.  



Click image to see an enlarged view

Fig. Unfasten the hose clamp, then disconnect and plug the hose from the reservoir

  1. Disconnect the primary and secondary brake lines at the PMV.
  2.  
  3. Disconnect the 4 brake lines from the PMV assembly.
  4.  
  5. Raise and safely support the vehicle.
  6.  
  7. Remove the lower PMV assembly retaining bolt.
  8.  
  9. Carefully lower the vehicle.
  10.  
  11. Remove the harness strap.
  12.  
  13. Support the PMV assembly, then remove the upper retaining bolts. Remove the assembly from the vehicle. If the unit is being replaced with another, the reservoir and bracket(s) must be transferred to the new assembly.
  14.  

The PMV assembly is not serviceable. Do not attempt to disassemble any part of the unit.



Click image to see an enlarged view

Fig. Pressure Modulator Valve (PMV) and related components



Click image to see an enlarged view

Fig. Exploded view of the Pressure Modulator Valve (PMV) mounting

To install:

  1. Position the PMV assembly and install the upper retaining bolts. Tighten the bolts to 20 ft. lbs. (27 Nm).
  2.  
  3. Install the harness.
  4.  
  5. Raise and safely support the vehicle. Install the lower retaining bolt and tighten it to 20 ft. lbs. (27 Nm). Lower the vehicle.
  6.  
  7. Connect the 4 brake lines to the PMV. Tighten each line to 11 ft. lbs. (15 Nm).
  8.  
  9. Install the primary and secondary brake lines, tightening each to 11 ft. lbs. (15 Nm).
  10.  
  11. Connect the hose to the PMV reservoir and secure the clamp.
  12.  
  13. Attach the electrical connectors to the PMV assembly; make certain each connector is squarely seated and firmly retained.
  14.  
  15. Connect the negative battery cable.
  16.  
  17. Install the air cleaner assembly.
  18.  
  19. Fill the brake fluid reservoir.
  20.  
  21. Bleed the brake system.
  22.  
  23. Clean any spilled brake fluid from the PMV assembly and surrounding area to prevent damage to other components or paint work.
  24.  

System Testing



Diagnostic Procedure

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

Diagnosis of the anti-lock and/or traction control system consists of 3 steps which must be performed in order.

  1. Visual inspection
  2.  
  3. Functional check
  4.  
  5. Additional testing as specified by the functional check.
  6.  

Some diagnostic procedures require that the ignition be left ON for an extended period of time while testing. Low battery voltage may result, causing incorrect readings or impaired system function. It is recommended that a battery charger be connected and a slow charge applied during testing.

Clearing Codes

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

Stored fault codes must be cleared using the bi-directional hand scanner. After repairs are completed, clear all stored codes and test drive the vehicle. Recheck for any newly-stored codes after the test drive.

Functional Check/Displaying Codes

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

If no problem is found during the Visual Inspection, the functional check must be performed. This test requires the use of a bi-directional hand-scanner, such as the General Motors Tech 1® or its equivalent. The scan tool is used to recover and/or clear stored fault codes during testing. The procedure also includes test driving the vehicle if necessary. Once fault codes or symptoms are determined, the test chart directs the use of the appropriate supplementary chart.

If multiple codes are stored, diagnose the code which first appears on the hand scanner.



Click image to see an enlarged view

Fig. Teves Mark IV ABS trouble codes - 1991 vehicles



Click image to see an enlarged view

Fig. Teves Mark IV ABS trouble codes - 1992-93 vehicles

Intermittent Faults

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

Faults which occur intermittently are difficult to diagnose. When diagnosing such problems, keep an overall view of system function in mind. Faults may result from low system voltage, low brake fluid in the PMV reservoir or any interruption of the signal(s) from the wheel speed sensor(s). Any condition interrupting the power supply to the EBCM or hydraulic unit will also cause the dash warning lamp to illuminate. Most intermittent or random faults relate to loose connectors or faulty terminals. Again, the visual inspection is of prime importance.

The diagnostic codes can be helpful in tracking intermittent faults. While not designated History or Current, certain combinations can point to fault status. Stored codes which do not light the ANTI-LOCK warning lamp are intermittent or history codes. If the ANTI-LOCK lamp is lit and one or more codes are stored, at least one (or more) of the codes is current.

Additionally, when diagnosing intermittent faults, keep the following system basics in mind:

  1. It is possible to feel the system self-test at very low speed if the brake pedal is barely applied. Both the sound (fluid returning to the master cylinder) and the slight vibration (valves cycling through test mode) are normal conditions.
  2.  
  3. Any fault in the anti-lock system will light the TRACTION light. When both lamps are lit, diagnose the ABS system.
  4.  
  5. The systems will disable if either the EBCM senses overheating in the brakes or transaxle. Once cooled, the ABS/TCS becomes available and the dash lamp(s) extinguish. This self-protective operation is completely normal but may become a source of operator concern.
  6.  
  7. When diagnosing an apparent TCS fault, make certain the TCS OFF switch is not engaged.
  8.  
  9. If a faulty wheel speed signal is suspected, check tires and wheels for matching sizes and tire pressures.
  10.  
  11. If necessary, the vehicle must be test driven to recreate circumstances causing the fault.
  12.  

The operator of the vehicle is the best source of information about fault occurrences. An accurate description of driving conditions will allow the fault to be duplicated during the test drive.

  1. Display, record and clear all fault codes in the EBCM.
  2.  
  3. Test drive the vehicle, attempting to recreate the failure conditions.
  4.  
  5. Safely stop the vehicle. Display and record the stored codes, if any.
  6.  
  7. If codes were stored, refer to the appropriate diagnostic chart. If no codes were stored, refer to the symptom chart.
  8.  

Visual Inspection

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

The initial visual inspection requires a thorough external check of both the conventional and ABS/TCS systems. Many faults are caused by items such as loose connectors, corroded grounds, failed fuses or low fluid levels. The visual inspection, when properly performed, will reveal these faults. Check the parking brake lever and cables for full release. Check the hydraulic system for leakage, line damage or restriction. System connectors should be tested for tightness; if a connector is suspect or has been exposed to moisture, separate the halves and check for corrosion on the terminal pins. Check connector shells for pin separation or push-out. Fuses in both the underdash and underhood panels should be checked. Correct the fluid level in the reservoirs if necessary.

Service Precautions

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999



Some vehicles are equipped with a Supplemental Inflatable Restraint (SIR) or air bag system. The air bag (SIR) system must be disabled before performing service on or around SIR components or wiring. Failure to follow safety and disabling procedures could result in possible air bag deployment, personal injury or unnecessary SIR system repairs.
 
The use of rubber hoses or parts other than those specified for the ABS system may lead to functional problems and/or impaired braking or ABS function. Install all components included in repair kits for this system. Lubricate rubber parts with clean fresh brake fluid to ease assembly. Do not use lubricated shop air to clean or dry components; damage to rubber parts may result.
 
Certain components in the ABS/TCS system are not intended to be serviced or disassembled. Only those components with removal and installation procedures should be serviced.
 
Always disconnect the EBCM and PMV connectors before any welding is done on the vehicle.
 
Never connect or disconnect the EBCM or PMV connectors with the ignition ON .
 
Use only brake fluid from an unopened container. Use of suspect or contaminated brake fluid can reduce system performance and/or durability.
 
When any hydraulic component or line is removed or replaced, it may be necessary to bleed the entire system.
 
A clean repair area is essential. Perform repairs after components have been thoroughly cleaned.
 
The EBCM is a microprocessor similar to other computer units in the vehicle. Insure that the ignition switch is OFF before removing or installing controller harnesses. Avoid static electricity discharge at or near the controller.
 
Never disconnect any electrical connection with the ignition switch ON unless instructed to do so in a test.
 
Always wear a grounded wrist strap when servicing any control module or component labeled with a Electrostatic Discharge (ESD) symbol.
 
Avoid touching module connector pins.
 
Leave new components and modules in the shipping package until ready to install them.
 
To avoid static discharge, always touch a vehicle ground after sliding across a vehicle seat or walking across carpeted or vinyl floors.
 
Never allow welding cables to lie on, near or across any vehicle electrical wiring.
 
Do not allow extension cords for power tools or droplights to lie on, near or across any vehicle electrical wiring.
 

Wheel Speed Sensor Rings



Removal & Installation

The toothed wheels which rotate past the speed sensors are integral parts of their respective assemblies. If the front ring is damaged, the drive axle must be replaced. If a rear ring is damaged, the hub and bearing assembly must be replaced.

Wheel Speed Sensors



Removal & Installation
Front

Specific to:

Buick LeSabre 1991

Buick Park Avenue 1996-1999

Pontiac Bonneville 1991

  1. Open the hood and disconnect the negative battery cable.
  2.  
  3. Detach the wheel speed sensor electrical connector.
  4.  
  5. Cut the strap retaining the sensor lead.
  6.  
  7. Raise and safely support the vehicle.
  8.  
  9. Remove the sensor lead from the brackets.
  10.  
  11. Unfasten the retaining bolt, then remove the sensor. Inspect the sensor face for metal particles, dirt or grease and clean off as required. The face of the sensor should show no evidence of contact with the toothed ring or other damage. If damage is noted, determine the cause and correct. The sensor should be replaced if the damage interferes with proper operation.
  12.  

To install:


WARNING
Make sure you install the wheel speed sensor cables properly, as correct installation is crucial to the ABS operation. Make sure the cables are routed through the retainers. If the cables are not clipped securely, they may rub against moving components, causing circuit and system damaged.

  1. Route the sensor cable, then install the retainers.
  2.  

If the wheel speed sensor is removed or replaced, the sensor body must be coated with a suitable anti-corrosion compound, where the sensor contacts the knuckle.

  1. Position the sensor in the knuckle. Install the retaining bolt and tighten to 84 inch lbs. (9.5 Nm).
  2.  
  3. Carefully lower the vehicle.
  4.  
  5. Attach the wheel speed sensor connector.
  6.  
  7. Install a new strap securing the sensor lead to the harness.
  8.  
  9. Connect the negative battery cable, then close the hood.
  10.  

Specific to:

Buick LeSabre 1992-1993

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1993

Pontiac Bonneville 1992-1993

  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle. Remove the tire and wheel assembly.
  4.  
  5. Detach the wheel speed sensor electrical connector.
  6.  



Click image to see an enlarged view

Fig. Front wheel speed sensor wiring - 1992-93 vehicles

  1. Remove the front hub and bearing assembly.
  2.  
  3. Gently pry the wheel speed sensor slinger off, using a suitable prytool. Discard the old slinger.
  4.  
  5. Remove the sensor by gently prying the bearing assembly off with a suitable prytool.
  6.  



Click image to see an enlarged view

Fig. Carefully pry off the wheel speed sensor slinger, then separate the hub and bearing from the sensor - 1992-93 vehicles

  1. Do not let debris get into the bearing while the sensor is removed. Do not add lubricant to the bearing through the sensor housing opening. The bearing is lubricated for the life of the vehicle. Do not clean the grease from the toothed sensor ring. The grease won't affect the sensor operation.
  2.  
  3. Inspect the bearing and sensor cap for any indication of water or debris entry. If you find any water or debris, you must replace the hub and bearing assembly.
  4.  

To install:

  1. Apply Loctite® 262, or equivalent locking fixative to the groove in the outer diameter of the bearing hub, per the directions in the service kit.
  2.  
  3. Using tool J-38764 or equivalent and a press, install the sensor.
  4.  
  5. Install the hub and bearing assembly and attach the sensor connector.
  6.  
  7. Install the tire and wheel assembly, then carefully lower the vehicle.
  8.  
  9. Connect the negative battery cable.
  10.  

Rear

Specific to:

Buick LeSabre 1986-1999

Buick Park Avenue 1996-1999

Oldsmobile 88 1992-1999

Oldsmobile Delta 88 1986-1988

Oldsmobile LSS 1996-1999

Pontiac Bonneville 1987-1999

  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle. Remove the tire and wheel assembly.
  4.  
  5. Disconnect the wheel speed sensor electrical connector.
  6.  



Click image to see an enlarged view

Fig. Rear wheel speed sensor wiring - 1991 vehicles



Click image to see an enlarged view

Fig. Rear wheel speed sensor wiring - 1992-93 vehicles

  1. Remove the rear hub and bearing assembly.
  2.  
  3. Unfasten the Torx® screws, then remove the sensor.
  4.  



Click image to see an enlarged view

Fig. Rear wheel speed sensor mounting - 1991-93 vehicles

To install:

  1. Install the sensor with O-ring intact.
  2.  
  3. Install the Torx® screws and tighten to 33 inch lbs. (3.7 Nm).
  4.  
  5. Install the hub and bearing assembly.
  6.  
  7. Connect the wheel speed sensor electrical connector.
  8.  
  9. Install the tire and wheel assembly and lower the vehicle.
  10.  
  11. Connect the negative battery cable.
  12.  

 
label.common.footer.alt.autozoneLogo