Mercedes-Benz CLS400 Steering Column Adjust Motor Replacement Cost

Many vehicles use electronic controls to adjust the position of the steering wheel for driver comfort. This replaces the manual steering wheel adjustment levers that are still commonly used. In vehicles with these controls, the adjustments to the steering wheel position is made by the steering column adjust motor, which allows the steering column to move in and out or up and down. There may be up to two steering column control motors per vehicle.

Much like the power windows or power sunroof in a vehicle, electronically positioned steering columns always rest inside of a track. When the button is pressed to move the steering wheel in one of four directions, a control module will recognize the input and cause one of the steering column adjust motors to turn. When turning, a toothed gear will engage the movable portion of the steering column, and cause it to move along its track in one single direction. This is even more similar to power seat adjustment.

When one of the steering column adjust motors fail, the steering column will fail to move in one or two directions, or may require some assistance to move the steering wheel when the switch is pressed. Also, in some cases, a grinding noise may be heard when attempting to adjust the steering wheel position. This would indicate the steering column adjust motor shaft has separated from the gear, or the toothed gear has been stripped out.

If the steering wheel is at a comfortable position for all drivers, this never needs to be repaired. It is purely a creature comfort feature unless one driver cannot physically operate the vehicle in the current configuration. If one or more drivers are unable to safely operate and maintain control of the vehicle with the steering wheel in its current position, they should refrain from driving the vehicle until the repair can be made.

This is not an extremely common repair. In fact, these motors are used so infrequently on many vehicles that they tend to last the lifetime of the vehicle. That being said, some luxury models adjust the steering wheel every time the driver door is opened, the key is turned, or a different key is brought into the vehicle. In these cases, the motors are more prone to failure, but still are not likely to fail frequently. Unfortunately, rates of failure for any of these motors or vehicles are unpredictable at best.

When pressing the switch to move the steering wheel position does not result in that action, the technician will listen for signs that power is making it to the motor. If the motor can be heard engaging, the relay is heard clicking, or ratcheting noises are heard from the steering column, the technician will understand that the issue is likely related to the steering column adjust motor, and inspection will begin behind the steering column trim panels. If the motor is either too weak to move the steering column, is separated from the gear, or the gear is damaged, the motor will be replaced.

After the decorative trim for the steering column is removed, the adjustment motors will be exposed, and removing them may be a matter of extensive deconstruction or simply removing fasteners and electrical connectors. Once the motors are installed, electrical connectors will be cleaned before reconnecting. Also, some vehicles will likely require calibration of the motors with the control module to ensure the control module relearns the path and extent of steering column travel.

Electrical diagnostics in general can be problematic, and there are many variables to account for. When electrical problems arise, diagnostics may take several hours to complete, or just a few minutes. This will significantly impact the cost of repairs. Choosing a facility with proper equipment and training for their staff may significantly reduce diagnostic time needed.

The steering column houses circuits for the supplemental restraint system (SRS) airbags, and there is at least one airbag mounted on the steering wheel. If proper procedures for servicing the steering column is not followed, deployment of the air bag or damage to the SRS is possible.

This can be a simple or very difficult repair. For the advanced DIY mechanic with a good understanding of working on and around airbag systems, it is likely possible to complete this repair at home. However, if safe working procedure is unknown, the repair requires extensive deconstruction of the steering column, or diagnostics is not understood, this repair should be left to a professional technician.