still no pedal response on R129

[sheffutd]

car,merc R129 2001 3.2L,now at garage with no throttle response but stops on idle prob.mechanic says message is being sent from potentiometer to ECU but cant tell wether its sending message to throttle body or faults with ECU.put a throttle body on that he had at home and made no diff but cant be sure it was working anyway.so its replace throttle body for £450 ish or ECU £1200or if make wrong choice both ,,thoughts anyone.

 

[E55BOF]

What does STAR say?

 

[sheffutd]

What does STAR say?

nothing as yet ,does,nt put management warning light on dash

 

[DrNick]

Mercedes | | Online catalogue | United Kingdom | BBA Reman will be worth a call

 

[DrNick]

First check would be to check the continuity of the wiring from the ECU to the throttle body if you are happy there is connectivity from the potentiometer to the ECU. Could be a broken connector or a broken wire.

 

[ray_hennig]

As these cars get older, it's a good idea to accumulate a set of replacement electronic modules. Test on arrival and put your old working one into stock.

Yes, you'll part with some cash but you'll have insurance. And, unlike insurance, your investment sits in stock and possible gains a little value as the years go by.

I bought a few EZLs for my 300-24 when eBay offerings were around 200€. It's difficult to find anything now below 500€.

I think I have a full set of electronics, all have which have been tested as OK.

RayH

 

[grober]

YOU MIGHT FIND SOME CLUES ON THIS GUYS YOUTUBE CHANNEL?

https://www.youtube.com/user/vsandvs/featured

Mercedes Throttle Possition Sensor Problem – MB Medic

Theoretically these drive by wire systems there is the throttle position sender and the throttle actuator however the throttle actuator signal may be modified by other inputs such as antiskid /traction control or cruise control it's possible one of these controllers has gone down and may be affecting the basic throttle position sensor input? Has your car got cruise control for example?

 

[Doodle]

nothing as yet ,does,nt put management warning light on dash

That's doesn't matter, not every code recorded will trigger a warning but they still exist to be read.

129s are surprisingly lax about turning on the management light anyway, I've encountered instances where the Lambda sensor was not even connected and it still didn't complain.

 

[sheffutd]

That's doesn't matter, not every code recorded will trigger a warning but they still exist to be read.

129s are surprisingly lax about turning on the management light anyway, I've encountered instances where the Lambda sensor was not even connected and it still didn't complain.

thanks for reply ,had 4 diagnostics on it .last of which was star n not found anything . think im going to fetch it back from where it is ,not a dealership but similar ,they dont seem to want to investigate ,just replace throttle body or ECU or both !n see what happens

 

[sheffutd]

YOU MIGHT FIND SOME CLUES ON THIS GUYS YOUTUBE CHANNEL?

https://www.youtube.com/user/vsandvs/featured

Mercedes Throttle Possition Sensor Problem – MB Medic

Theoretically these drive by wire systems there is the throttle position sender and the throttle actuator however the throttle actuator signal may be modified by other inputs such as antiskid /traction control or cruise control it's possible one of these controllers has gone down and may be affecting the basic throttle position sensor input? Has your car got cruise control for example?

yes it has

 

[grober]

This is a useful site for cruise control problems.
Home — Cruise Control Repair
unfortunately the later models of the R129 have much more integrated circuitry which needs MB star system or equivalent to troubleshoot. Trying to repair problems on these later models should take this route- replacing modules blindly is an expensive way to attempt to solve problems.
E.G.

Cruise control quit working

www.benzworld.org

 

[sheffutd]

hi every body ,hard t beleive but still not fixed,ecu bin to repair shop twice but they say its ,several gmechanics bin thruogh wiring ,last on says ecu sending message to throttle body but not able t recieve anything back so thinks it s ecu at fault ,there bit expensive if turns out not t be that .anyone know a specialist older merc ,2001 r129.guy ,chesterfield or sheffield.desperate !