Some forum members may have seen my other posts about making lowering links for the EQS SUV. I did make a couple different types of links, but never installed them since I was not comfortable removing the front factory links. The brackets attaching the front links to the upper suspension arm are not very robust. I had hoped to have a tool made at a local machine shop to facilitate the link removal without damaging the bracket, but this project was never completed.

When I became aware of the option to lower the SUV remotely with coding changes I decided to explore this approach. I liked the idea that coding the ride height would be less obvious compared to replacing the links with non-factory links. I ordered the OBD remote coding dongle from RJ Automotive in the UK and scheduled a session to lower the suspension.

My goal was to lower both the front and rear by 15mm. This is the same amount that the suspension is lowered when driving above 75 mph in Sport Mode. During the first session, an issue with the left front ride level sensor was discovered. The sensor was indicating readings that were significantly outside of the possible range. During this first session I was not properly prepared to accurately measure the changes made during the coding session. RJ was asking me to report changes in millimeters and I had to keep converting the measurements I was taking from inches to millimeters.

To make matters worse, I had scheduled a medical appointment after the coding session and we had to end the session before finishing the job. At the end of the session the left side was lowered by about 25mm and the right side was lowered by about 10mm. The SUV was listing to the left. Fortunately, this unbalanced condition did not generate any error messages. I actually liked the look of the side lowered by 25mm. But, I was concerned that the additional 15mm drop that takes place in Sport Mode might be too excessive.

Before starting the second session I purchased a 500mm long ruler and fabricated a “slider” from a couple of business cards stapled together. This setup facilitated measuring the distance from the wheel arch to the center of the wheel. I sent a photo to RJ showing how I would be taking measurments. This is when RJ realized that I had downsized from 21” to 20” wheels. He indicated that coding changes should have been made to accommodate the smaller tire size with changes for the suspension and speedometer readings. RJ speculated that the left front ride sensor may have shifted to an out of spec condition with the new wheel size.

We struggled to get the suspension to the desired 15mm drop because of the issue with the front left sensor. It was very difficult to get all four corners to the same level. Twice during the second session I drove a few hundred yards to settle the suspension before taking measurements. In the end, the front was lowered by about 15mm and the rear was lowered by closer to 20mm. With both sides at close to the same level we ended the session.

Since the rear was lowered more than the front, the headlight angle was out of adjustment and several oncoming drivers were flashing their bright lights. I turned the headlight adjustment screw for both headlights one turn counterclockwise to lower the headlight beam and oncoming drivers stopped complaining.

After lowering the SUV I checked the negative camber for the rear axle. The factory specs call for -0.8 to -1.8 degrees. When I had a wheel alignment 5000 miles ago, the rear camber was -1.5 degrees. Now it is just out of spec at about -1.9 degrees. The top of the range for an ICE MB SUV is about -2.6.

Given the issues we encountered lowering the SUV with coding changes, I would probably change the length of the links if I did this again.


500mm ruler to measure distance from wheel center to wheel arch.


Headlight adjustment "screw"


Checking camber angle on rear wheel.

 

Lowered EQS 450 4Matic SUV