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Matt, Mechanical Engineer
Category: Mercedes
Satisfied Customers: 22727
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I have w202 c(NNN) NNN-NNNN- using cruise control uphill, at 110kph

Customer Question

I have w202 c(NNN) NNN-NNNN- using cruise control uphill, at 110kph down shift to 4th and then a sudden down change to 3rd - deceleration and accelerator pedal has no effect even after disconnecting cruise control. Stan
Submitted: 4 years ago.
Category: Mercedes
Expert:  Shantal-Mod replied 4 years ago.

Hello Stan,

I've been working hard to find a Professional to assist you with your question, but sometimes finding the right Professional can take a little longer than expected.

I wonder whether you're ok with continuing to wait for an answer. If you are, please let me know and I will continue my search. If not, feel free to let me know and I will cancel this question for you.

Thank you,


Customer: replied 4 years ago.

I'll wait for advice. additional information car has travelled 120K km

Expert:  Shantal-Mod replied 4 years ago.
Hello Stan,

Thank you for the additional information. We will continue to search for a Professional to assist you.

Thank you for your patience,

Expert:  Matt replied 4 years ago.

I'm assuming that this is the automatic gearbox ?

So what does the engine do if try and rev it up in neutral?
Customer: replied 4 years ago.
Engine runs fine, just when a steeper slope will do a double change down very rapidly and apart from high revs loss of some power. If I disconnect before the hill, all ok by using more throttle and a gentle auto down change.
In the cz control situation pedal doesn't appear to work, lot of slack not even spongy.
When I disconnect just prior to auto down change everything ok. But hard to judge.
Expert:  Matt replied 4 years ago.


i'd suggest 1st checking that the cruise control cable to the throttle on the engine is tight and not slack

then check the condition of the cruise control connections the module is located under the cover on the l/h side of the bulk head

unplug it and spray the connections with switch cleaner

Customer: replied 4 years ago.

I have done as suggested, cable a little bit slack, had a mechanic look at the control iunit but couldn't fault. took a week to get the car out to some steeper hills but still preforming the same, rapid shift down x 2 and car slows to 70 from 100 so dangerous for following irate drivers. Starting to look like VW problem???? what next, am having the auto transmission serviuced with new oil etc.??

Customer: replied 4 years ago.
Tried the above but no change. Took a while to test in hilly country but still same forcefully down change and loss of power. No slack in cable, unit serviced by auto electrician but still fails.