These suggestions and solutions for technical problems come from service bulletins and other technical sources at Mercedes-Benz. They are selected and rewritten for independent repair shops. Your Genuine Mercedes-Benz Parts source can obtain any item designated by a part number.

Wheelspeed Sensor Replacements

All Models with ABS

The most common ABS problem is likely physical damage to a wheelspeed sensor caused by impact damage with road debris.  Most often such damage affects the harness, and certain kinds of harness damage can be repaired by splicing the harness itself.  In other cases, you have to remove the old sensor and install a new one.

When doing so, there are several precautions to follow.  There are slightly different torque specifications for different models, so check your manuals.  Note that on a 202 and perhaps on others some sensors have a locator sleeve that fits between them and the knuckle.

Before you install the new sensor, take the opportunity to rotate the wheel slowly while you inspect the teeth on the rotor very carefully using a flashlight.  Remove any particles between the teeth; replace the rotor if you find broken teeth.

-WIS

Swaying SL Suspension 129 with ADS

If you find an ADS-equipped SL with a ride that makes you wonder whether there are any shock absorbers in the car at all or even whether the road is attached securely to the planet, don’t immediately start unbolting the shocks.  If you don’t see visible hydraulic leaks in the dampers or along the lines, it is possible there is one or more defective accumulator on the system.

There are accumulators and height sensors for each wheel.  The suspension units work height sensors as the wheel goes through jounce and rebound.  The control unit then routes or vents pressure as needed.  The accumulators for the rear axle are in the trunk and simple enough to replace.  Those for the front are inboard of the towers and not notably harder to access.

-WIS