Ford Transit TDCi, low power, low boost (p0235) – Fixed!

Low power/boost on Ford TDCi engine

On our last trip to France, our van experienced what appeared to be a major fault, such that it struggled going up hills which is unheard of for these vans! It was as if the turbo wasn’t working properly, or for whatever reason the van was sluggish as pie. We did some basic checks in France and decided it was safe to continue till we got back to UK for further diagnosis. This diagnosis was VERY thorough and as this seems to be a “common” fault I decided to write up all the tests so they could be useful for someone (and me!) should similar happen again.

What I found was that there were many trivial problems that could cause this (or similar) issue.

My “problem” and “fix”

My particular issue was, would you believe, caused by *someone* swapping the EGR and Turbo Actuator Vacuum hoses around (!!!) – aPipes on wrongnd it wasn’t me as until I undertook my research to diagnose the issue I didn’t know what the hoses were for…. And during the time the van was well, to the time we noticed the fault, it was only out of my posession once at a “trusted” garage…… And, of course, they deny all knowledge and accuse me of questioning their integrity and now refusing to speak lol…. Actualy “mate” – no. If I was diagnosing a fault and had an identical van next to it, its par for the course to look at another one and compare. I would, I asked them and a friend to do checks on similar vans for me, and if I had one nearby I’d have asked to do the same! I almost hired an identical van so I could compare! I’d not worry about people using mine. However, on this ocassion, someone put the pipes back on backwards! And actually, for a fact, one of the team there DID compare a van on your site with mine that did involve removing a vacuum pipe – so saying its not something you would do is laughable.

Not saying it 100% was them, but ipipes on correctlyt certainly happened when in their posession, so it was either them, the bodyshop they took the van to and left it there, or the tube-swapping-fairies.

The fix (once found) took 30 seconds to put right, simply by swapping the vacuum hoses back to the right connectors.  No harm done, just frustraiting!

In future, I will be photographing the engine before leaving the van anywhere, not just the exterior which I used to do!

Thanks and Credit

This article will hopefully be useful to someone, but beyond typing it I cannot take all the credit. Some friends helped me out for advice, and a number of guys on forum gave me pointers, accurate information, specific information and tips – one of which identified the swapped pipes. Without these guys, I’d have been lumbered with a huge bill from a garage (possibly the same one mentioned above) for diagnostics and fixes.

I strongly recommend that if you have a transit and an issue, then chat to the guys on – and search their archives as there is a HUGE amount of information there, and lots of willing people who know a lot (and I mean a LOT) more than me.


I am an IT guru, I am not a mechanic. The information here is specific to my van, a 2005 Mk6 Ford Transit SWB280 FWD 2L TDCi. Whilst I know some information is common between other TDCi variants, the specifics are ONLY for ME AND MY VAN. If you decide to use MY PERSONAL NOTES on your van, please be aware this is entirely at your risk and of course you should not believe anything I say and you should take your van to a trusted garage! Do not attempt to do anything that I have!

Characteristics of fault

Bizzarely, the van drove quite well – on the flat (Wiltshire!) it drove fine, felt maybe slightly down on power, but really nothing to worry about. Of course its a campervan so we don’t thrash it or drive fast. MPG same as normal (mid 30’s), starts first-time every time, and idles fine.

The main way to notice the fault were:-

  • At 3200rpm, when static on drive, the van would stutter (as if on a limiter) and smoke before exceeding 3200rpm. When driven, this was fine.
  • Going up-hill or on overtakes when power was required, it was flat. It’d still get up the hills but slower and a gear lower (e.g. feeling like an old van)
  • No extra smoke or noise.

Note I did NOT have a MIL (engine management) warning light on the dash at first. Only after I paid Ford £90 to update the ECU to the latest software was the fault detected. Once the new software was on, the van entered LHM (Limp Home Mode) so was worse to drive (doh!) – with the error being “p0235 turbocharger boost sensor a malfunction”. At least this helped focus the mind….

(If you have issues starting, or a rough idle, you are likely to have other problems than here)

Possible areas to check

Here is a list of checks I did, each is explained further down the page

  1. Brakes
  2. Fuel Pump / Injectors
  3. F-Super Diagnostics
  4. MAP Sensor
  5. MAP Sensor wiring
  6. MAF Sensor
  7. MAF Sensor Wiring
  8. Fuel Filter
  9. Air Filter
  10. Turbo (Inlet)
  11. Turbo boost pipes
  12. Inlet Manifold
  13. Intercooler
  14. EGR
  15. Vacuum pump
  16. VNT Actuator
  17. VNT Vacuum pipework
  18. VNT Solenoid
  19. ECU Reset
  20. Cat/Exhaust

Tools and stuff to buy

I bought the following tools to help me sort this out, and they were necessary! (the links are to the items on Amazon, if you click and buy, I get 5% sales comission from Amazon. I bought some stuff from Amazon and some elsewhere.)

  • : This interface and software allows a Windows Laptop to talk to the Transit ECU and read/reset error codes, and also to see sensor readings. This is pretty much essential for diagnoising issues. Its not as good as Fords system (£1800!) but good to do quite a bit with!
  • : This tool is essential to undo (and do up) the hose clips that latch on. Yeah – you can do it with a screwdriver and pliers and a lot of swearing, but this tool makes it simple!
  • Multimeter and Piercing Probes: Essential for wire checking
  • : Replacement MAP sensor if yours has failed. Of course, check part number. NO NEED to buy direct from Ford – a genuine Ford garage quoted me £380 for the part as they refused to sell just the sensor, only as part of a new intercooler!!!
  • : Essential test kit to test the MAP sensor, vacuum pipes and the actuation of the VNT turbo. Godsend!


  • If you do continuity tests on wires/sensors, best to have the battery disconnected to save ECU
  • Unplugging pipes/sensors as part of the diagnostics may trigger other fault codes (e..g disconnect a sensor, you may get sensor fault; disconnect a pipe you may get airflow fault).  f-super deals with this
  • Don’t trust Ford entirely – their engineer didn’t find the swapped hoses (despite being told low/no boost; and despite having a computer that could test turbo actuation – which would instantly show it didn’t move when expected which would quickly show the swapped pipe!)
  • These are MY NOTES – they may be useful for Transit or Mondeo TDCi engines or other engines, but don’t take them as gospel!

P0235 error

After my ECU update and the newer software detecting a fault, the van then moaned about P0235 – “turbocharger boost sensor A malfunction”.  What this really means is “the data I am getting from the


Silly as it sounds, check all 4 corners and ensure your brakes aren’t sticking/binding. If they are, this can give the impression of lack of power.

2.Fuel Pump / Injectors

Fortunately I didn’t need to examine these, but these can be a cause of low power. However, from my research a fault with either of these would typically flag a DTC identifying them, or you would have other symptoms – like poor starting or idle. This subsystem is quite complex, and almost certinly left to an expert.

3.F-Super Diagnostics

is a rather good, and cheap, interface to allow you to see information that your ECU knows. So, such informaton can include temperature, RPM, boost pressure, fuel pressue etc. Diagnostis interfaceIt also allows you to read (and clear) DTCs as necessary. As not all codes flag up a MIL light, it is worth checking anyway.

The interface port is under the steering wheel.

A point to note, my late Mk6 didn’t flag any error codes, but after a trip to Ford and £90 later, they updated the ECU software and the newer software did indeed flag a code (and put the van into limp mode 🙁 ) – however this did help me diagnose where to focus my attention even if Ford read the code and insisted the MAP sensor was faulty (even though I didn’t think it was).


With f-super, some key bit of information:-

  1. BARO is air pressure, and is out by a factor of 10. So 100 is roughly 1000mb. (MAP sensor). Should be roughtly 99-101 depending on the weather and altitude. Note on images mine is 88 – thats because I was up in the Alps!
  2. MAP is manifold absolute pressure, and is in effect boost pressure. It is in effect a factor of 100 out! (see MAP sensor). On idle, it should match BARO (x10), and on revving to 2-3000 revs should read up to 14. (Boost pressure in PSI = (( 10xMAP ) – BARO ) x 0.145. So, if BARO = 100, and MAP = 14, then PSI = ( (10 x 14) -100 ) x 0.145 = (140 – 100) x 0.145 = 40 x 0.145 = 5.8 psi boost
  3. IAT is inlet air temperature (from MAP sensor which is actually a T-MAP sensor)
  4. APP1-3 is throttle position
  5. FRP = fuel rail pressure
  6. MFdes is metered fuel

The rest of the readings are obvious, so look at what they are. The temperatures should all be logically correct.

I’ve included some images of f-super on my van which may be useful to compare – the only thing to rememeber is these were taken in the Alps when the turbo wasn’t connected properly, so MAP (aka “boost”) will be a lot lower than it should be.

Throttle offThrottle floored

RPM increasing RPM decreasing Idle Engine off


4.MAP Sensor

Ford, in their £90 diagnostic session where they failed to test the turbo actuator or notice the vacuum pipes were wrong, simply saw the P0235 error and said it was a faultly MAP sensor. After trying to charge me £380 for a new sensor and intercooler I bought just the sensor from a parts place opposite, fitted it in 2 mins, proved it wasn’t it – and then was told “tough – come back another time to continue diagnostics”….

Anyway, the MAP sensor is a TMAP sensor which reads boost pressure, air temperature, and also atmospheric pressure. Absolutely no idea how it does the latter….


This is located on the off-site pipe at the bottom of the intercooler. It comes off simply with 2 star-shape (torx) screws. The electrical connector unplugs. On other vans this is near the EGR and hence gets gunked up – so if its dirty, MAP sensor on intercoolerclean it gently – it should be spotless (mine was). Also clean and check the electical connectors. Mine looked all fine and actually gave correct readings in f-super – so why Ford said it was faulty….. ARGH! lol!



Anyway, using the

and some DIY scraps, you can make up some pipework to plug the MAP sensor in (when off the van, but connected electically). You can then run and then change the pressure in a vacuum. Removing 500mb of pressure should make the MAP reading in f-super read 5. In addition I used a bike inner-tube (cut) to put the MAP under pressure, and putting 10psi pressure around the MAP sensor probe, you should get a reading of 17 or so on f-super. (see f-super section for accurate maths)

You can also directly check voltages (thanks to Dan @

The map sensor loom has 4 pins;
1. MAP reading
2. 5v reference
3. IAT reading
4. Earth

So… With ignition on pin 2 should read 5v and pin 1 should read 1.5v
At engine idle pin 1 should still read 1.5v, with a little throttle the voltages will increase to about 3.9v roughly.
Pin 4 should earth with no resistance (0 ohm)
Discount pin 3 as it works the iat sensor.

5.MAP Sensor wiring

On the forums, and a friends experience, the wiring to the MAP sensor can corrode or wear through. If you clean the sensor wires you can see they are colour marked – make note of these. Note each wire has a PRIMARY colour and then a thinner SECONDARY stripe. This is important – white with green stripe looks similar to, but is different to green with white stripe!

The wires go into a loom and cover, up near the radiator, under the AC pipes, behind the air-filter housing, across the windscreen to the ECU on the near-side top part of the engine above the coolant bottle.


  • Check the wiring to the plug
  • Open and check the loom from the MAP sensor up – reports of corossion up to 10cm away from plug
  • Check wiring behind air-filter housing (a bitch to get to if you have AC and after market cruise control!) – a friends had worn through here due to bad fitting at Ford.
  • I personally openned the loom near the ECU (tape unwraps), found each of the 4x MAP wires, and with BATTERY DISCONNECTED I checked continuity between here and the plug (using automotive piercing probes), also I checked for shorts to ground, all whilst wrigging the cable along its entire route.

So its essential that there is 100% continuity at all times, and there are no shorts to earth. The exception is Pin 4 which should be earth and 100% continuity to earth at both ends.

6.MAF Sensor

The MAF sensor measures air flow being sucked in via the air filter housing. The ECUMAF sensor uses this to determine how much air is in the system and how much fuel it can lob in. So a duff sensor can mean very poor power.


This is simply held in with 2 torx screws. Once removed be gentle as the element is very very fragile.


If you think you have a faulty MAF, the “internet says” to simply disconnect it! The ECU will revert to a safe program assuming safe settings for what the MAF should be. If the van drives the same/better, then the MAF is faulty. If it drives worse – it isn’t!

You can clean the element – gently – with a cotton bud and electrical cleaner.

You can test the voltages on the sensor and you should get, roughly:-

  • Pin 2 (to earth): 12v (12-14v)
  • Pin 5 to earth, on idle, 1.7v
  • Pin 5 to earth @ 3000rpm 3,4v

In other words, Pin 5 voltage should vary smoothly depending on RPM.

7.MAF Sensor Wiring

Similar to the MAP sensor wiring, I would treat this the same. I checked all the way back to the ECU loom. See MAP sensor wiring.

8.Fuel Filter

The vans appear very fussy onfuel filter fuel filters as the fuel filter is particular to the TDCi engine as it is a finer filter than the TDDi. So, ensure you have a new and GENUINE and TDCi fuel filter. If you did a DIY change, ensure you did it properly to avoid air in the fuel lines – remember the TDCi does not have a fuel lift pump!

If you haven’t got a genuine TDCi filter – put one on.

If at any time you’ve had a non genuine or a TDDi filter on, then you may have fuel pump/injector issues…

9.Air Filter

A dull possibility, but check your air filter! If its clogged it will starve the engine of air and hence power. I’d take this further and check the airbox and the inlet pipe to the grill – you don’t know if a bird is nesting/rotting in there! Check the pipes to the air resvoire and ensure they are all spotlessly clean.

Check all pipes are in good condition and not split

Simple, but worth checking

10.Turbo (Inlet)

Remove the pipe from the air resovoire to the turbo inlet. Its a bit awkward to get at the turbo side, but do this and ensure the pipe is clean. It is also linked to the crankcase breather, so ensure there isn’t gunk there.Turbo inlet


Once the pipe is removed you can actually stick a finger in the turbo and touch the compressor rotor. Spin this manually and ensure it spins easily and freely, and ensure there is no play in/out or side/side if there is, then you have a turbo issues of some sort. It should not move much beyond rotating freely.

Once that is clear, reassemble and I would suggest removing a “Boost pipe”, maybe the first one (from turbo to intercooler) as its easy to get to. Then start the engine, and at 2000rpm air should be blown out. If no air is blown out at all, then your turbo isn’t working or the pipes are blocked.

See sections on boost pipe & VNT actuator for futher tests.

11.Turbo boost pipes

Post turbo, the pipes will be (or should be) under pressure when the engine is being revved or driven. As such the pipes will be under pressure and leaks may become apparent. The problem is, at idle, there isn’t always enough pressure to show leaks.

I took off and manually checked every pipe from the turbo to the inlet manifold. There are rubber pipes to inspect for signs of wear on joins, or splits, or any form of damage. There is also the EGR pipe which is metal where someone on the internet has had a pipe split and needed it welding. So check everything.

Pipes are fairly easy to get off with the exeption of the ones connected to the turbo boost outlet! There, there is a short flexible bit of rubber, linked to a plastic thingie, then to a rubber pipe. All mine were in perfect condition but it was easy to see how pipes could split and not be evident from a visual test.

Any leak would give lack of power, so check carefully, and reassemble well!

12.Inlet Manifold

The inlet manifold sits under a few bits, so see HERE for instructions on how to remove it. This is worth checking as if you haven’t blocked your EGR valve, all the exhaust crap will be going into the inlet manifold and blocking it up. I’ve seen pictures with 30% gunk! Mine (with blank EGR) was 99.9% clear 🙂

But worth taking off, checking and cleaning.

Also, inspect for damage and cracks, again someone on the internet has had a cracked inlet manifold which would vastly reduce boost pressure. Definately inspect carefully.


Bearing in mind the turbo pipework is connected to the crank breather pipe, and the EGR is linked, then any gunk/oil in the air will accumalate in the lowest possible point – which is the intercooler. Many people have blocked intercoolers which will restrict the flow of air and thus boost pressure.


I would take off the in/out boost pipes of the intercooler, and clean up one of the sides.  Then simply blow through it.  You should get fairly free-flowing and unrestricted air going through.  If it is excessively dirty or restricted then you will need to clean it out or use a new intercooler. (You can’t bypass the intercooler as the MAP sensor would then not get a boost reading and you would cause a boost error DTC!


The EGR is a valve that sends dirty exhaust gasses back into the engine for a second burning.  This is entirely for emisssions control, but the side effect is all the crap in the exhaust goes back through the valve, back into the inlet manifold and makes a mess.

On the Mk6 van the EGR is vacuum operated and does NOT have any sensor on it – so this means you can block it and stop it sending the dirt into the engine!  This means the engine gets cleaner air and there are no side effects.

On my van, the EGR failed (due to getting covered in soot) which is common, so I disabled it.  See HERE for detaild of EGR fixing.

15.Vacuum pump

The vaccum pump is bolted to the engine, and how it works is beyond this scope.  However, what it does, is provide a constant vacuum to the devices that need it – namely the brakes and the VNT/EGR solenoids.

All we care about here, is to ensure there is enough vaccum being sent to the VNT/EGR solenoids.


There are 3 vacuum pipes that run across the engine next to the oil filler – one goes to EGR, one goes to VNT, and one goes up to the top of the engine, then left towards the brake servo.  This is the one we want to test as it is this that provides the vacuum needed to operate the turbo.

Locate this pipe and pull it apart on the 90′ elbow.

With engine off, using the

– test the pipe in both directions, ensure the vacuum holds.  (if not, check pipes)

With engine running, connect to the side of the pipe connecting towards the vacuum pump – and this should suck > 70 kpa and be constant.  Any less, check pipes and ensure vacuum pump is OK

16.VNT Actuator

The VNT actuator is basically a vacuum operated lever which controls theVNT turbo actuator variable veins inside the turbo, and hence the amount of boost.  The ECU should adjust this constantly based on boost demand and RPM.


  • With engine not hot, feel behind where the arrow is and find the actuator.  This feels like an old throttle cable type setup.
  • With engine off, the actuator should be relaxed (back), and you should be able to pull it forward with one finger. Let go, it should spring back.  If not, your VNT is probablu crudded up with carbon and will need clearning.
  • Assuming it is smooth and moves freely, continue tests….

The way it should work is:-

  • On engine off, relaxed
  • On ide, pulled in
  • On revving from idle to 3000rpm fairly gentle, the lever show go back slowly

If so, it is behaving

If not check:-

  • Using – connect to actuator and apply 65kpa vacuum.  Whilst applying and increasing vacuum, the actuator should be pulled in smoothly and fully at 65kpa.  When vacuum released slowly, lever should move back.
  • Actuator should move at least 10mm between “on” and “relaxed”
  • When vacuum applied to actuator, it should remain.  If it leaks you’ve got a broken vacuum diaphragm.Inlet manifold elbow

To check to ensure the VNT is moving, remove the 90′ intercooler elbow and start the engine.

  • On idle, with vacuum off (and turbo relaxed) there will be only a very very small blow
  • On idle, with vacuum on (and turbo in) there will be a gentle blow

If this is the case, turbo is working!


17.VNT Vacuum pipework

If the turbo is working by manually applying vacuum but not always automatically, check the pipework.  Trace the VNT vacuum pipe back back to the solenoid, and it should be connected on the top (see next section).  Disconnect from solenoid and apply vacuum to that pipe.  65kpa should move the actuator fully and the vacuum should hold.  If not, you have a leak.

Note – my issue was someone swapped the VNT pipe to the EGR pipe on the 90′ elbow to the right of the oil filler – so check carefully that it goes back to the correct solenoid.

18.VNT Solenoid

Vacuum solenoidsThe VNT solenoid is basically an electronic valve that applies vacuum based on input voltage – thus the ECU controlls this valve to control VNT position by varying voltage.  This is on the off-side part of the engine attached to the bottom of the air-filter box.  (removing the air intake pipe makes access easier)

It has an input from the vacuum pump, and outlet to the air filter which are shared between the EGR and VNT solenoids.  And the top solenoid (green plug) controls the VNT actuator the bottom solenoid (black plug) controlls the EGR.


  • With engine running, unplug the pipe coming from the vacuum pump – check you get >70kpa vacuum
  • With engine running, check that at least 65kpa is being sucked in on the VNT pipe
  • Check the green plug is in correctly, and when engine idling, it has 12-14v on one pin, and 10+v on the other pin.  (between pin and earth).

In my tests, on idle, the green plug is powered and vacuum is demanded and actuates the VNT; then unplug the green plug and vacuum is released and turbo relaxed.  Ensure the green plug/top pipe is to VNT!!!!!

19.ECU Reset

Last resort that did nothing for me, but as the ECU “learns” how the vehicle behaves it tunes itself accordingly.  Disconnecting battery for 48 hours resets all these parameters…. As I said, last resort….


It was mentioned that blocked/failed CAT or exhaust could restrict air flow out, so something worth considering if you feel this is the case.  I “tapped” the entire length to see if anything sounded solid, but beyond that I assumed it was OK.  To be fair, it “felt” and “sounded” okay.  But, cats fail and block the exhaust so don’t rule it out.

Do note, TDCi VNT engines do not like being de-catted!  TDDi engines are, apparently, ok, but don’t do it on a TDCi without research!

48 thoughts on “Ford Transit TDCi, low power, low boost (p0235) – Fixed!”

  1. what an excellent article! I’ve an early Mondeo mk3 TDCi, and your info with photos is a really useful and excellent reference for me and undoubtedly many others. Thank you for sharing this good stuff 🙂

  2. Pingback: 2014 Plans…
  3. hi Ryan-Mel
    there is so much info attached to this link i will save it and be sure to refer to it for help in the future i have a mondeo mk3 tdci 2.0 130psi 2005 model about 6 mths 145,000mls fully serviced good history i would appreciate if you could help me to narrow down a problem
    your thoughts would be great full
    last week the glow plug light came on and the turbo shut down temperature gauge runs below normal it has an electric actuator which i have opened and all looks good it moves one postion when engine start but just remains still after that the turbo arm and veins are working as should egr/manifold cleaned is open/closing all pipes are good diagnostic report said turbo boost controller apart from the actuator would the map sensor cause lost of boost or any other parts relating to boost control just trying to eliminate small cost first you no yourself
    happy travelling 2014 thanks
    regards chris

    1. Thanks for your comment, but I am sadly not a mechanic  I’m a DIYer who correlated the information I needed from the internet to help me.

      I know nothing about an electric actuator – only the vacuum one. But I would say, can you compare against another Mondeo of same spec? I really can’t comment on how it behaves vs. the van engine.

      You really need a specific code from the computer. The MAP (or T-MAP) sensor can read wrong and prevent boost – e.g. if the sensor is unplugged, the ECU probably won’t request boost. That should be easy to check with F-SUPER or some other Ford compatible code reader. You can take the map sensor out, make sure its clean, and pressurise it (e.g. I attached some pipe and a bike pump!) – and then the ECU reading would change by valid amounts. So this showed it worked and hte wiring was fine. On the transit, wiring faults are “common” – but if the ECU is reporting correct values then the wiring works.

      But the exact error code is needed, then google that on both the transit and mondeo forums

      Sorry I’m not being much help….

  4. Thank you for such an excellent article. You have given me the confidence to deal with my transit problems head on. Now I understand what does what and how. Well done my friend

  5. Hello, I also have a camper build on Ford Transit 2005, it`s a 135T350 with a 2.4 TDCI engine. I`m looking for a scantool so I can look at the DTC codes myself. I have some trouble with the engine running unstable. Do I understand you wright when I say that the F-super cable works find in my transit?

    Hope to hear from you,

  6. Hi i have a ford transit long wheel base
    Had problems starting found pump to be at fault before this i found two relays gray ones
    1 felt hot the other okay so i swaped them round and turned key and smoke pored out of little red wire nere battary gose to battery jump point so braught new relay conected wire and tured key burnt again …so had new pump installed and coded in still wont start pluged in code reader and said no power to relay any help

  7. Awesome read.

    I have a Transit that constantly switches to “Limp mode”
    It appears to have a Low Pressure fuel rail problem but we have replaced and check everything, including new Injectors and Rail. Very frustrating indeed. Still no fix

    1. If I can give any advice it would be check the simple thinks first don’t take them for granted
      I replace every thing I could before finding the problem with was the turbo vacuum solenoid.


  8. Where does the vacum hoses go to I am having the same problem with my van and it’s got me baffled everything’s working as it should just slow and I can’t find a vacume diagram gurrrr

    1. IIRC – from brake vacuum pump to solenoids. One goes to turbo actuator, one goes to EGR. Pipes run up from OS side of the engine under air filter, up, through plastic sheath behind injectors, and go off to EGR/Turbo.

  9. Hi I’ve been following your steps for curing the low power problem with the transit because I have a 2004 mk6 2.0 TDCI Minibus with exactly the same problem.
    Taking for granted and assuming my vacuum pipes were in the correct place and the skipping first part of your article I proceeded to test further steps in the article.
    I have since found out the problem seems to lie with my vacuum pipes but after correcting them I still had the same problem I.e low power going in to limp mode glow plug light flashing etc etc.
    I have done all basic checks i.e. checking the pipes for splits but when I came to check the voltage on the green plug on the solenoid I found one of the wires had no voltage.
    One of the wires had 12 to 14 V but the other had no voltage at all.
    So my question is should there definitely be a reading from both and do you or anyone know where these two wires go to as I have followed the wire with no voltage chasing it back to the right hand side looking at the engine behind the water coolant bottle but then loose where it goes.
    I have strong vacuum coming from the vacuum pipe but once connected to to solenoids and to the turbo the vacuum isn’t as strong and is as if there not enough suction for the turbo actuator to work correctly.
    Any help regarding the wires would be appreciative of any further help regarding vacuum.

    1. Hi.
      You may want to pick up a cheap vacuum test kit to see if there is sufficient vacuum at the turbo. Check all pipes for leaks.
      The solenoids will only get voltage when the ECU wants a vacuum (or not, don’t know which way it goes).
      On startup, my EGR vacuum was “sucked” then eased off after a few seconds (10-20)
      On startup/idle, my turbo vacuum was sucked and stayed sucking till the van wanted to change its position.
      So, on my van, after say 20 seconds, as EGR vacuum request is “off” and Turbo vacuum request was “on”, I’d expect different voltages at the solenoid as they are doing opposite things. Its all from the ECU. Easier to test with vacuum kit.

      (I’m no expert!)

      Can you move the turbo actuator by hand? Also – with a cheap vacuum test kit you can test how much suction is required to move it – (figures above).

      Good luck

      1. Hi yes I’ve go a vacuum test kit and all pipes are good.
        My turbo has constant vacuum on start-up/idol but still not as I would expect but if I bypass the solenoid and put the pipe straight from the vacuum to turbo it pulls the actuator fully.
        It’s only when connected to the solenoid that it doesn’t fully pull actuator complete.

        I appreciate your no expert neither am I just a DIY mechanic hoping I’m looking for a bit of help so I am very appreciative of your time

  10. FIXED.
    I’ve finally found the problem with my transit minibus.
    I was having the exact same problem as the person who wrote this article and after several tries and tests it’s worked out to be a faulty turbo vacuum Solenoid.
    The fault code was the same as on hear P0235.

    1. Nice one!
      The vacuum test kit listed here may have helped – but without knowing the behaviour of the solenoid its hard to prove either way. You need a working van next to you to test. I think this is what was the root cause of my issue – the garage used mine to test for someone elses van and just put it back wrong. Bastards.

      1. Well either way I am very grateful for your rights up it has been my bible to my problem.
        Do you know of any way of getting just that little more power out of the engine tho.
        It’s running great I just wish it had a little more sometimes.


  11. Can anyone tell me how to find out what a P3100 Fault Code definition is for my 2004 Transit 2.4 tdi.
    Thank You
    Kind regards
    alan livingston

    1. Hello. No idea, and my searching found you already posting on forum which I was going to recommend. Afraid I can’t offer more, apart from making the question public in the hope someone finds it. Hope you get it sorted!

  12. Tube swapping fairies, and other members of their tribe, swarm here in Australia. My city of the Gold Coast is an “open prison for fraudsters”. Thankyou for your efforts on behalf of we poor Transit camper owners. Mark.

  13. Hi very informative article,glad you got your problem sorted.The problem I have on my 2.4 durotorque 05 plate is when its in top gear roughly 50-60 mph wont go any faster than that when I put my foot down through to top gear the vehicle suddenly feels very lumpy like fuel restriction.your thoughts would be much appreciated cheers David.

    1. No idea – I’ve never touched a 2.4 – the article was for my personal van only, but the checklist should be the same. Of course, injectors and fuel pump could be the issue too. Best bet is to go to forum and ask there – but just do the obvious tests listed here first 🙂

  14. Hi can u help we got a pick up 2.4 before the turbo went on last week it was onlly doing 40 mph then the turbo pack in we put a turbo on yeaster day and it still doing 40 can y help us please

    1. Beyond whats on this page, I know nothing, and I’ve never seen a 2.4 So hopefully someone else can help. Also look at the forum – those guys know their stuff. Good luck

  15. Excellent write-up !!! thanks, loads of great info.
    Just one thing ,where you mentioned the P0235 code it seems to be unfinished ?

  16. Great article! Being a Transit owner I have bookmarked your page just in case…
    Very many years ago as a youth, my first experience of car ownership involved a visit to the main dealers; they lied to me, treated me like s**t, didn’t even fix the problem (I had do it myself) & charged me a fortune for the pleasure. I have avoided them like the plague ever since! Your experience with Ford doesn’t surprise me in the least.
    The trouble with modern vehicles is the technology! All those sensors potentially giving false & misleading reports to the ECU. Added to which are the dealers who think they’ll make a few 100 quid out of you when they think it’s an easy job. Or who are incompetent or maybe can’t even be bothered to diagnose the problems properly, when a dedicated amateur can eventually work it out for him / herself.
    Good on ya! I always like a self taught enthusiast.

  17. Thank you for taking the time to write up your problem and the detailed process that you followed in order to find the solution. There are so many people on here that post a question, discuss it at great length and then don’t have the decency to let everyone know the end result. You have helped me find the answer to my own problem which, as it happens, was almost exactly the same as yours. So, once again Thank you.

    1. Glad to help!
      It was a b***ch to find, and only due to anonymous internet help was I able to fix it – so happy to give back
      Always good to know others find it useful, so thanks 🙂

  18. Main agents should not be allowed work on or service motors,
    Two year old with oil leak, had van for four days and decide it was the pipe going in to the turbo.
    Collected van pool of oil on drive , returned to them again kept it for three days took off the oil pan and resealed it, back on the drive and you guest it more oil.
    they then could not do anything till the end of month. Having a little know how jacked up motor with the aid of light found oil pipe bottom engine to turbo split. Main Agent close them down

  19. Just writing to give a huge THANK YOU, you have been the most helpful aid after a few weeks looking for some information to fix my van (same as yours).

    Problem was the same and finally found that black and black/white vacuum hoses were not wrong, but one of them was not attached, so problem solved, amazing.

    Anyway, I link your blog to continue with the long list of maintenance you show here in order to keep my van as healthy as possible.

    King Regards.

    1. I wondered if anyone on here can help me, I’ve recently bought a mk6 transit that was originally a tdci but has a tddi engine fitted. The issue is no boost and I have now realised that there is no sensor on the intercooler pipe (the usual 4 pin type) and the only plug in that location on this one is a 2 pin one. There is an electronic sensor on the bulkhead with a small air pipe coming out of it, also there is no sensor on the air filter box either I’m stuck.

      1. Hi, I cant help, but would suggest you access the transit forum ( – they helped me massively
        Good luck

  20. Very helpful. We have power loss on our 2002 2.4l Duratorque powered campervan and as yet have not resolved the problem. It’s going to a vehicle electrics specialist and if he needs pointers I am sure this will be useful to him, if he has not already seen it.
    I agree with most on here that going to a Ford main dealer would probably be a very expensive waste of time. Will let you know how we get on.
    Thanks Nick

    1. Good luck!
      I do hear the occassional good story of just “diesel specialists” – like man-in-van who only do diesel diagnostics…. No experience of any but consider that too. Diesel engines are fairly simple on one hand, its just the specifics and tuning that makes them complex! So a good guy would be clued up. (For the new van, 2.3 Ducato, Ill be buying the full OBD interfaces and software! Ford aren’t experts sadly, just (IME) barely trained technicians with zero diagnostic skills (a good diagnoser would’ve found fault in 15 mins using the Ford IDS software correctly: Think Turbo issue eh? “Actuate turbo”. Hmm didn’t move. But the solenoid clicked. Check vacuum (OK). Solenoid (OK). Hmmm Tube blocked? Oh………. But only diagnositics was code read (MAP pressure wrong, no shit) – needs a new intercooler/MAP sensoer. (Despite me saying I’ve had the sensor off and validated readings on ECU). Shocking. GOOD LUCK! 🙂

  21. 2002 2.4l Duratorque Transit – Update

    June 2021 – Fuel pump ‘examined’ by ‘specialist’ and pronounced ‘in good order’
    Seven months of further diagnostics (involving hours of effort and expensive labour) following advice found here and on other forums to no avail:
    February 2022 – Fuel pump examined by a different ‘specialist’ and found to be faulty. New pump (£750 + labour)) fitted and all is well.
    Moral: Choose ‘specialists’ carefully. How I don’t know.
    Thanks to all of you.

    1. Yeah – tough on isn’t it! I’m addicted to Diagnose Dan on YouTube – worth watching a few – thats how expert diagnosers should be. Sadly, most aren’t 🙁

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