1999-2001 Isuzu NKR, NPR, NQR ABS Workshop Manual

• 71-page official ISUZU publication (LGBRK-WE-0101, first edition January 2001) covering 1999–2001 NKR, NPR, and NQR trucks equipped with Anti-lock Brake System (ABS) and Anti-Slip Regulation (ASR) variants
• Provides original diagnostic documentation and repair reference data for the four-channel ABS control system used across the N-series truck platform
• Contains 26 circuit diagrams, 17 diagnostic trouble code (DTC) charts, and 4 specific speed sensor inspection procedures

Component and System Documentation

This 1999–2001 Isuzu N-series manual documents the ABS and technical diagnostic protocols for medium-duty trucks. It provides detailed system architecture for the Electronic Hydraulic Control Unit (EHCU). You will find exact breakdowns of solenoid valves, plunger pumps, and wheel speed sensors. Furthermore, the text outlines specific diagnostic interactions with the Tech 2 scan tool. This includes plotting snapshot graphs, interpreting data displays, and performing actuator tests for individual components such as the return pump relay, solenoid valves, and the exhaust brake cut relay.

Specification and Inspection Data

This reference includes comprehensive inspection parameters, covering speed sensor output voltage, circuit resistance specifications, and tightening torques for braking components. The manual specifies 22 N-m for front sensor bolts and 221 N-m for disc assembly bolts. It also details the specific hub bearing preload values required for both new and reused bearings. Diagnostic charts support the identification of electrical faults through pin-out voltage checks at the J-500 connector, ensuring correct system operation for both 12V and 24V electrical architectures. Working on hydraulic brake systems involves critical safety components. All service data shown here is for reference only, as qualified technicians and the original OEM documentation remain the authoritative source for any hands-on repair.