Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Anti-Lock Brake System - Diesel (G Series): Diagnosis: Notes
The Vehicle Control Module (VCM) contains a self-diagnostic capability to detect system failures. When a DTC is set, the VCM may disable 4WAL system and illuminate ANTI-LOCK light for duration of ignition cycle. DTCs stored by VCM can be displayed using Tech 1 and appropriate cartridge.
Before diagnosing 4WAL system, perform a comprehensive visual inspection of system by checking wiring harness connectors, harness routing (pay particular attention to wheel speed sensor wiring harness routing), applicable fuses in fuse block, and ground connections. Ensure brake fluid level in master cylinder reservoir is full.
Start 4WAL system diagnosis using DIAGNOSTIC SYSTEM CHECK . If failures are found when performing diagnostic system check, you will be directed to enter diagnostics to retrieve DTCs or perform SYMPTOM TESTS. DIAGNOSTIC SYSTEM CHECK may indicate that system is functioning properly.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.