Preparation for Test: 1. Vehicle battery must be sufficiently charged (electrolyte specific gravity: 1:3.6) 2. Check fuses OK. 3. Model 129 without ADS and model 140: Rear axle sensor (headlamp range adjustment) (A51) and front axle sensor (headlamp range adjustment) (A52) are mechanically ok. 4. Model 129 with ADS: 5. Front axle level sensor (B22/2) and rear axle level sensor (B22/3) are mechanically OK. Electrical wiring diagrams (location of grounds and connectors): Electrical Troubleshooting Manual, Model 129, Volume 2, group 82, Model 140, voulme 3, group 82

Conventional tools, test equipment

Description	Brand, model, etc.
Multimeter 1)	Fluke models 23, 83, 85, 87

1) Available through the MBUSA Standard Equipment Program