I'm getting ready to install a Renntech ELM on my 03 E55 and wanted to know what is the best/easiest way to determine if my car has 3 wire or 4 wire sensors for the airmatic system. The build date for my car is 03-03.

You probably have the 4 wires. The sure way is to jack you car up and look at the sensors in the front wheel wells.

No you have a 3 wire. Meaning you can only control the ride hight for both front shocks seperately but the rears are controlled together. 3 controls front left, front right and rear. You can not control the rears seperately.

This is the only way to know for sure. Just locate the sensor and pull back the wire cover and count the number of wires leading to the sensor. If you haven't already seen this DIY post, I think you'll find it helpful:

https://mbworld.org/forums/w211-amg/...te-diyers.html

I think the OP is talking about the actual number of wires in the sensors. From what I remember, all '03 and most '04 have 4 wires sensors. Some late '04 and all '05 and up have 3 wires sensors.

Ahhh....I see. The Renntech manual breaks it down by production month and year.

Thanks all. Well - turns out it's a 4 wire. Thanks Komp55 for the thread with the install pics. That's helpful. I just got a used Renntech V1 that I bought on Ebay for $300 - price was too good to pass up. I guess the only difference in the installation is that I'm cutting the wires instead of pulling the pins out of the airmatic harness.

I'd like to get your thoughts on a different installation approach. I'm thinking it may be better to buy my own molex quick disconnect and wire harness so I can extend the wires and locate the module in the glove box or other more convenient location. It would also be great if I could find a pin connector that would accept the stock pins kind of like how the V2 is designed and then purchase some pins to solder on and insert back into the stock harness. Just hoping to avoid the "cutting" if possible.

I wouldnt cut crap on my car! JMO That is why the V2 is light years ahead.

I agree with emoving's opinion on this. Maybe you can resell the v1 on eBay. It would be worth spending the extra cash to get a used v2 or v3 which do not require any factory wires to be cut. I prefer the v2's remote, which allows adjustment on the fly, and can be conveniently located just about anywhere you want to run the connecting wire two. I've had zero issues with my v2 plus remote since the day I installed it.

Gents,

I think I have come up with a better solution to selling the V1 and purchasing a V2 for another $350 or more. I purchased for $12.50 a package of male and female crimp-style terminal pins the same size as the terminal pins on the Mercedes Airmatic terminal block. I am crimping the female pins to the ends of the sensor-side wires and male pins to the wires that send to the Airmatic box from the ELM. After inserting the male pins into the female pins, I'll wrap electrical tape around the exposed metal. The new crimp on male pins will insert back into the terminal block exactly like the stock pins. It will be totally reversible and no cutting of wires by just removing the black tape.

Granted, I won't have the remote function, but I extended the wires on the ELM and am mounting it to the inside bottom of the first aid kit box in front of the seat. That way, I can leave the cover off if I want without it being damaged by occupants. I moved the first aid kit to the drivers side. I'll send pics after it's done...

good idea with the compartment, looking forward to seeing!