Hi, I recently bought a Multipla 2001 1.9TD ELX 105 JTD. It required a new turbo which has been replaced, but ever since it has a problem with overboosting. The first mechanic was unable to locate the problem after blanking the EGR, replacing the turbo boose pressure valve and replacing both the MAF and the MAP sensors. The second mechanic thinks it is a wiring problem or an ECU problem due to no vaccum to the turbo actuator. The car is not in limp mode but goes into overboost at 3000 revs. Also, the brand new battery has been drained of power. Everyone in the forum seems to be pretty clued up on these things, can anyone please advise which route I should take next as they both seem rather pricey

Any thoughts at all are most welcome.

Many thanks

check the red or blue coloured hose from solenoid to wastegate (especially here at the sharp bend) very carefully. You can see it clearly with bonnet open (look straight down)

Thanks, will try this and get back to you.

Had my fingers crossed but unfortunately not. It was a red hose and we carefully checked it as suggested but could find no leaks or splits. Thanks very much for the advice though..

does wastegate operate?

Not sure. How would we be able to tell? I have to be honest and say I'm not completely sure what the wastegate looks like, never mind how it works...
We followed the red hose so am assuming it's the part under the car at the end of the hose. Sorry if I sound such a numpty! I really do appreciate your help.

have look here;

https://www.fiatforum.com/multipla/241169-fiat-ecu-scan.html

Many thanks, we're going to take a good look at the pipe and wastegate etc and check and clean everything really carefully. Will let you know how it goes

hi, i have had similar problem for 6 months now!, i have replaced...
maf sensor, map sensor, overboost valve, red tubing & egr valve. still no joy. did you find a remedy in the end?. thanks. mark

Snap! Sounds like we have exactly the same problem. Pretty much everything has been replaced but the problem remains. No vacuum to the turbo actuator - It's so frustrating! :bang:
Have followed every single piece of advice given through the forum previously but nothing has changed ... My partner has an electrical diagram but no instruction so it's really not much help! Will ask him if he can upload it and maybe someone can identify which wire may be the problem. Worth a shot! If you can find a solution in the meantime please let me know

hi, thanks for quick reply. yes its soooo frustrating, engine management light on, i cancel it with fiat ecu scan & obd2 cable after every effort to solve it with new parts etc & as soon as 3000 revs reached while driving the dreaded beep comes & management light comes back on. if i re-set management light with laptop & go to say even 4000 revs light doesnt come on at all - its just while actualy driving!. its insane. i even took it to a good garage (good reputation) they said they sorted it with their software & took it on good road test. i had my doubts- & sure enough driving home the bl**dy light came on again!!. with light on there is a lack of power particularly with a full load.
sounds like our problems are identical... & wev both had them for around 6 months now?.
i rarely use the car due to the lack of power once light on & use my 5
seater runaround with 4 kids squashed into the back- which is both illegal an cramped, but we have no other option as money is very tight, its a nightmare.

please do send me the wiring diagram & tell me all you have done so far to try to remedy.
one of us must be able to sort out this nightmare- & then we should both be sorted!.
thanks
mark

Hi, it sounds EXACTLY the same problem, won't go above 3000 revs and stays in limp mode. Yep had it about 6 months now and cannot get an MOT or road tax until fixed but haven't got the finances or time to spend on it. I think we've both done exactly the same things to try and fix the problem and it keeps coming back to ECU and Wiring - neither are cheap options. Have opened the ECU and there are no signs of any burnt contacts or anything that looks a problem so have to assume it's the wiring. Am currently using my old Fiesta and doing what you do - just squeezing the kids in - what else can we do??. Will upload a diagram shortly and maybe hopefully someone can identify which wire is which or at least which wire leads from the ECU to the turbo actuator.. Fingers crossed!

Hi Here is the electrical diagram for a 2001 Fiat Multipla 1.9 JTD ELX. If anyone can help identify the wire from the ECU to the turbo actuator I will be extremely grateful. If you are having difficulty enlarging the diagram to a readable size I will happily email you a larger copy. Seriously - any help at all will be gratefully received!

hey, mines in for the mot re-test on wednesday, they say it wont fail with or without the engine light/fault present, its in for re-test as i have just fitted new front discs & pads (old ones seemed fine with loads of life left in pads, but too much of a difference in braking power between wheels which is mot fail & they were happy to do the new discs/pads for me for £230 inc parts,fitting & vat, i did myself other evening for £76 all in. the garage is going to replace two front springs that have snapped for the mot though (i didnt even know they had gone, but could see quite clearly they had while doing discs & pads).

i looked through some of your threads, could it not be a leaking actuater?,
the dome shaped bit at end of turbo that the red silicone hose from the overboost valve goes to?, have you ruled this out yet?, i wasnt aware this could happen until seeing some of your posts...so this might be my next experiment with it.
thanks for the electrical diagramme, it makes no sense to me, but maybe to someone that knows this stuff.
i hope for both of us we crack this one soon. mark

forgot to add:
i have the fiat ecu scan software & obd2 cable. with this software i have executed a test on the overboost valve & you can hear & feel it work.....
so the wiring to it (i presume) is ok.
i just cant help but think its a lack of sufficient vacuum somehow

I had something similar with mine earlier this year. Went to Optima near Swindon as Nick sorts out most things for me. Spent £50 on a new pressure sensor (the one tucked around the back of the cylinder head). Thought it had sorted it - revving to 4000+RPM and no engine fault light. However, he told me to take it out and rag it for a few minutes. Sure enough, at the first decent clear bit of road I floor it in fourth (feel the raw power!) and the dreaded beep and fault message comes up at just over 3000RPM. Trundle back to Optima in limp mode.

Nick then traced the (red) tube round to the front of the engine and down behind the rad to where it pushes into a short length of rubber tube (about 2" long) with a woven outer sleeve. Once it was removed, a close inspection showed that it had partially split along its length - no more than 1/4". However, this was enough to prevent a decent vacuum seal onto the red tube. Two minutes later Nick emerged from the back of the workshop with a replacement piece snipped from I-daren't-ask-what, pushed the tubes into place and voila. Problem solved. To be honest, I could tell that it was fixed from the moment I pulled away because the pick-up was noticeably smoother.

Might be worth a look.

Hi, thanks so much for your advice. Was advised it would fail MOT on emissions as I cannot get it above 300 revs to test it. Have not heard of a leaking actuator.. how would you fix that?? Happy to explore EVERY avenue... The fault is definitely no vacuum to the turbo actuator. Have checked all round this and the wastegate opens and closes, no leaks on the pipes and everything seems to work as it should when you manually test it - it's just when the car is running it doesn't seem able to do these for itself :bang: Have done the same as you and had the codes cleared but as soon as we boot it, the car bleeps and the code returns. There are a lot of clever people on this forum and am really hoping someone takes pity on me lol!

Sorry widemouthfrog, didn't see your response until after I'd posted. Glad to know you're in my area so may have to take it to Optima! Was lead to the red tubing a while ago and I cleaned it and checked it and found nothing but to be honest it looks very new. As I've just said everything seems to work manually, it's just the car that can't seem to make it work :bang:

Hi, your diagram does look like an autodate diagram. if you have the key to the wire colours then i can tell you the circuit that you need to check!
On your diagram B105 is the boost actuator. it is supplied with power (usually 5volts) from pin 93 from the ecu on wire colour og/sw. the negative for this component goes from the actuator back to the ecu on wire hbl to pin 95. so basically you should be able to put a volt meter on these two wires and see 5volts. There is a third wire, 'signal' which is wire gr/ge this runs from the actuator back to the ecu on pin 94. this is the wire that's signal will vary from say 0.5 of a volt up to usually about 4.5volts depending on the load of the engine. you also need to check the wires for continuity and i would 'load test' the wires. this is done by disconnecting ecu and the actuator and introducing 12volts up one of the wires at a time and checking the other end with a 12volt bulb of 21watts not a cheap led tester.this will prove that the wire is capable of transmitting current, any defect in the wire will be magnified in use as it is trying to get 0.5volts to 4.5volts to and from the ecu. hope this helps

justin

hi again,
to pass mot (not the answer to sort car out i know) but... have the code cancelled at garage doing mot, as you know car will rev happily unless being driven & will certainly rev to 4000 plus revs while stationary, thus pass mot & emissions test. thats mot test passed...but not our dreaded
problem solved.
i am determined more than ever to have this solved one way or another!.
out of 12 months, the multi has been drivable for only 6!!. what a waste of expensive road tax and insurance!!.
i am getting mot on wednesday (2 days time), but will not tax or insure it
until problem is solved (keep it on drive).
either the garage must sort it...or more likely myself. as its not garages money i just have the feeling they will advise expensive parts that most likely will not fix the problem. if i knew a part would definately be a permanent fix i would have it done whatever the cost (borrow some money!) . we have to have our car back.
will keep you informed of progress.
it sounds like both are cars do have identical fault, so fix one & both should be sorted