GM Full Size Vans 1987-1997 Repair Guide

General Information

Print

See Figures 1 through 14



Click image to see an enlarged view

Fig. Fig. 1: RWAL brake system diagram



Click image to see an enlarged view

Fig. Fig. 2: RWAL wiring diagram



Click image to see an enlarged view

Fig. Fig. 3: RWAL connector pin-outs



Click image to see an enlarged view

Fig. Fig. 4: 4WAL hydraulic system - 1996-97 models shown



Click image to see an enlarged view

Fig. Fig. 5: 4WAL component locations - except 1996-97 models



Click image to see an enlarged view

Fig. Fig. 6: 4WAL component locations - 1996-97 models



Click image to see an enlarged view

Fig. Fig. 7: Three sensor 4WAL brake system diagram - except 1996-97 models



Click image to see an enlarged view

Fig. Fig. 8: Four sensor 4WAL brake system diagram - except 1996-97 models



Click image to see an enlarged view

Fig. Fig. 9: Three sensor 4WAL brake system wiring diagram - except 1996-97 models



Click image to see an enlarged view

Fig. Fig. 10: Four sensor 4WAL brake system wiring diagram - except 1996 models



Click image to see an enlarged view

Fig. Fig. 11: 4WAL connector pin-outs - except 1996-97 models



Click image to see an enlarged view

Fig. Fig. 12: 4WAL brake system diagram - 1996-97 models



Click image to see an enlarged view

Fig. Fig. 13: 4WAL brake system wiring diagram - 1996-97 models



Click image to see an enlarged view

Fig. Fig. 14: 4WAL brake system connector pin-outs - 1996-97 models

There are two basic types of anti-lock systems available for this vehicle; a Rear Wheel Anti-Lock (RWAL) brake system and 4 Wheel Anti-Lock (4WAL) brake system.

The RWAL system components consist of the Vehicle Speed Sensor (VSS), the Electronic Control Unit (ECU), the isolation/dump valve and the Vehicle Speed Sensor Buffer (also known as the Digital Ratio Adapter). The ECU also receives signals from various brake switches.

The 4WAL system components consist of the Electro-Hydraulic Control Unit (ECHU) valve (also known as the Brake Pressure Modulator Valve or BPMV), the wheel speed sensors, Vehicle Speed Sensor (VSS) on 3 sensor systems and the VSS Buffer.

 
label.common.footer.alt.autozoneLogo