W163 ML270 Retrofit Onboard Trip Computer

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Active Member
Jul 20, 2014
2007 R320 CDI Sport / 2003 270ML CDI Inspiration
Ive read loads of guides and forum threads on retrofitting the onboard computer. Ive got a couple of questions and was wondering if anyone on here had done this and could share their experiences.

1) why do some people cut a hole in the lens? Presumably factory fit would show through the lens?

2) I have satnav (and so must have a compass sensor) some units communicate with the compass, what feature does that provide?

3) Did the factory installed models have the tow switch elsewhere in the cabin?

4) Is there a definative list, table or link to correctly identify which unit(s) would work on my car?

Please keep the thread updated, interested in this as a friend is keen to retro fit it to his ML :thumb:.
From what Ive read it just plugs in and works as they wired all ML's up for it - Im not sure why the American's didnt just make it standard? The dark plastic bit is different on those with and without the trip computer. I noticed the complete unit as photo'd sell for less than just the trip computer module. My suspicion is that those stripping and selling complete dont realise the trip module was an optional extra. Its worth noting all it really does is give MPG and miles to fill up. Had the M Series been a German built car I expect it would have told you about blown bulbs etc like on others Benz of this age.

I'll let you know how I get on.

Fitted in less than an hour. Just remove old and connect new.

Do this with KEY OUT.
1) Remove light lenses. Clip to the rear.
2) Remove middle cover, clips rear first. Both sides with small thin screw driver.
3) Remove garage door opener cover, 1 clip to the rear. 2 hinge clips both sides push up and out.
4) Undo 4 screws.
5) With medium screw driver push large clips forward from the rear of the clips and pull down at the same time. be careful not to break these. They are hooked onto the steel roof structure.
6) Lower light and unplug wires. ( clips on all) Sunroof switch 2 both sides and one on the bottom. Top ones lets it hing downwards ( opens it up) so you can get plug back in later. (large clip in the way). Interior light plug got clip but easy.
Trip plug clip on the bottom. I unscrewed trip and then, removed light fitting leaving just the trip computer, and moved clip back and pulled out connector.
7) Screw back the new trip computer
8) Re-install in reverse order.

Not sure its really worth it but all working!


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