Turbo Boost Pressure Solenoid 31293964
 

Hi, does anyone happen to know what the resistance reading should be on a Turbo Boost Pressure Solenoid 31293964 please or where I can find this information?

Currently going through a fault-finding session and trying to rule things out.

Mine is reading 11ohm. Saw a video where 30ohms was mentioned...

Thanks

..31293964 tbps
 

The above part number comes up as a two port "switch/gate" ( I use this term because "turbo boost solenoid " means different parts to different people with different cars)
I can't help with the ohms reading (but IIRC it is low), however Si Robb on his Utube channel until recently, had two videos about cleaning /stripping the valve inside the part down and cleaning it. ( crud makes it stick/ not move smoothly) I have the occasional over-boost issue which I place at this parts door. My 2015MY is a twin turbo D5 and IIUC this part opens a gate to move boost air to the 2nd (larger) turbo at about 2000RPM. As I rarely exceed 2000RPM I live with the occasional problem, which is why I probably got the problem in the first place LOL. :)
Hope this helps.
Cheers Bob.

Thanks for your reply Bob.

You are right regarding the different names used. I believe Volvo call it a 'Governor' (see picture attached).

Had seen that videos too, but mine is slightly different and there is no easy way to dismantle it. I could attack it with a screwdriver in an attempt to take the plastic cover off (bottom right bit on the picture) but with my luck I'll probably snap something off.

Hopefully somebody here has an idea regarding the required ohms..?

What is more indicative of the thing perhaps not functioning properly is that when I gently blow on one of the ends, air comes out of the other. My understanding is (quite possibly wrong :thinking:) that it should not let air through when there is no charge on it, and open when under charge.
Thoughts anyone please?

The joys of low revs cruising! :cool:


I'm actually investigating the reverse. I'm getting an underboost...

Following 2 codes:

ECM-P029900 Turbocharger/Supercharger A Underboost Condition
ECM-P003A85 Turbocharger/Supercharger Boost Control A Position Exceeded Learning Limit - Bus Signal / Message Failures - Signal above allowable range.

Have done smoke tests on any hose I could get my fingers on and couldn't find a leak.

Had a look at all the possible parameters within VIDA and all seem to be reporting sensible data.

Not got to the turbo/VNT actuator itself yet, as the weather here has been pretty bad and I have to work outside.

Tempted to run an 'Adaptation turbo system' but not sure if this could do more harm than good. If there is a mechanical fault somewhere, the ECM might 're-learns' the wrong thing...
Thoughts?

) What year/model is your car? Si Robbs video is for single turbo not Bi turbo so the use of these components may be different even though they are the same item. However as we appear to be on the "same page" I'm assuming its a 2 turbo engine. As you have Vida do you have dice too? There is an activation sequence somewhere which "tests" the 2 gate ( which should Vibrate when activated) and the 3 gate components, which just clicks. According so the Si video the piece you refer to is held with 4 tags/Clips which have to be released. The internal mechanism is released via the housing at the top RHS of the image, But it appears to be a plastic ring holding the bits rather than a crimped metal fastener.
I understand your pain about smashing stuff with hands of clay - that's why I ain't moved with my issue.

If you have a "Mitty" vac or equal you can test both actuators for operation, but that means removing x2 pipes ( one one *3964 and one (the "T" one IIRC) which runs down to the larger turbo waste gate. on the component next door( two actuators fastened on one bracket???)

Finally IIRC the default position for the valve is "open" in as much as when Si in one video squirted cleaning solution into one of the two "gates" the dirty solution came out of the 2nd gate - This is what you have- but it could be stuck in this position and in need of a clean...

Cheers
Bob

Thanks Bob, your insights are greatly appreciated.

It is an S80 D3 Automatic, Engine: D5204T3, year: 2012
(chassis No: 152371)

I do have a Dice too and just enough knowledge to be dangerous... :tounge_smile:
Attached the options I have. I'll have a little prod.

Also a screenshot on the turbo.
I see VIDA comes up with multiple options for my D5204T3 though (36001168, 36001767).

Mine is somewhat different unfortunately and does not have those tags/clips.
Also, mine doesn't have that metal fastener; it is plastic parts pushed together to make it not accessible.

Might try that next, to see if that shows something obvious. Is easier than trying to get to the turbo itself (which I might end up having to do eventually anyway) as that is pretty hard with the limited space between the turbo itself and the bulkhead.

A, OK, I thought default was closed. Could be, like you said, that it is simply stuck in position.

Thanks and I'll see what else I can find

Ok Your engine is only single turbo and suspect *3964 may be used in a different way on my engine than yours, but the method of operation should be the same across all engines.
I'd try to flush it - see what if anything comes out.
Try to get Vida to operate it.
After that other than trying a replacement I'm a bit stuck.
If you did get an ebay special, you could play with that trying to take it apart - if it gets broke its not a total loss, you still have the original, If you do get in and clean it etc thats a win win.


Perhaps others might offer a fresh insite..

Cheers
Bob

Had a similar idea like you and managed to get a (cheap) second hand one yesterday but it gives no difference in what I see in the data. Not sure if it is one of my best ideas though, as both my original and the new one could be faulty.
But like you say, at least now I can go to town on one of them and see if I can get into it..

I've attached some pictures of the data I'm getting. The most obvious sign of something not being quite right is the "ECM - Turbo Position". The thing is clearly being controlled, but not quite as it should.
It says the turbo position should be above 80% at idle but sits around 50%.
Closed position is OK
'Turbo position 60%' button drives it to around 80%....

The above makes me think that perhaps it 'forgot' somehow what the positions should be, therefore running the 'Adaption turbo system' might solve the issue. However, if something else is the cause I don't want it to learn the wrong thing if that makes sense.

Perhaps the other pictures tells you something useful? Put the idle and 2000 rpm data together in one, so it is easier to compare.
Anything out of the ordinary there, please?
Temperatures are somewhat optimistic as it is only 12C here but have used the car earlier today so perhaps warm under the bonnet?

Finally, looking at the 'Turbo control valve, bypass or VNT'(*) I noticed the following. It tells you to START it and then look at the Turo Position Sensor data again. This time I get:
Idle now sits around 71%.
Closed position is OK
Turbo position 60% button drives it to around 73%
When I however going back to 'Control returns to the control module', it now drops to 0% which it doesn't do without the 'Turbo control valve, bypass or VNT' function activated.

All very weird to me and no idea what could cause this. Any idea please?

Many thanks,

Vince




*="Activation is only possible with the engine running. Verify that the activation works by reading off the reconnected parameter from the turbo position sensor, or by checking visually. Note! Certain software versions do not have reconnected parameters. In these cases, only visual checks can be made.

Also see diagnostic service for activation under DIAGNOSTICS/VEHICLE COMMUNICATION/ECM/Advanced. "

vaccum 'solenoid' in the pic
 

Interesting thread, looking at the vaccum 'solenoid' in the pic, some of these are simple on-off type ports that either apply a vaccum to the (far side) or switch off the vaccum, usually to operate a mechanical arm or something like perhaps on a turbo the VNT vane position etc to control boost at different engine RPM, pierburg make a lot of this sort of product (found a pic attached of a similar looking part. It looks like there is a round section that is probably a stepper motor or similar that allows a progressive movement between full vaccum (or pressure if is uses pressure) or anywhere inbetween no vaccum to 100%. Suspect if you have a look at the 2 wire (12v) signal it may be a PWM type signal to set it at the desired position ? with no power, is the port open or closed? Whats on the far end of the tube (turbo?) side.

Hi Thassos, thanks for your post.

How would I go about testing that please..?

When I gently blow on one end, air comes out the other. I thought it should be closed when no power is supplied to it. Your thoughts?
Annoyingly, the same happens with the second-hand one I got. So either they are both good or both broken.:tounge_smile:

Does anyone here know for sure what it should be, please?

Also tested them by connecting them to a battery, and I can hear it does something. So nothing obvious at fault there.

It goes to the vacuum wastegate actuator.
In my post #5, I've included a diagram of the turbo and where the vacuum hose goes.

The fault could very well be with that part or the Turbo itself, but my plan was to go throught the easy bits first in the hope I don't have to get to the turbo in this weather :regular_smile:

edd chinavac
 

Morning,, i had missed your drawing in post #5 (so much for speed reading!), would the pierburg part be item 12? and the vaccum actuator the round component below the turbo? with no number?

Some questions & things to try..

A) you mention applying 12v (would suggest using a DVM to probe the 2 wires going to the pierburg 'solenoid' to see what polarity they are before applying 12v in same polarity. If you blow on the port when 12v applied, does it pass thru or close flow of air?

B) Well worth getting a cheap chinese version of a mityvac, or maybe use a large syringe with tube and attach to the capsule to see if you can make the turbo actuator move with vaccum applied, sometimes you can freely move the arm or linkage with no tube attached, or get an idea of what resistance there is to moving the linkage incase its something internal to the turbo.

C) You might also use the 'mityvac' attached in place of the capsule to see if any vaccum is getting applied via the 'solenoid' similarly with engine running, (again just ideas here..) Also see if the tubing run back from the capsule will hold a vaccum - incase of a split or poor / missing tube connection.

Usually on pwm type connections one side is permanently (chassis, or +12v feed) and the other is switched on-off on a regular time loop that is giving the %age from fully open to fully closed. No idea if this applies here but with 2 wires to something there are only a limited number of ways it can work ! the signal will be coming from the ECU from one or both sides, might also be worth using a dvm to trace the wiring back to the ecu plug (just use a small bit of small guage wire to 'probe' the connector without pushing something oversize in it that might cause damage,..) incase its a broken electrical connection (prob less likely).

If you have a DVM, but not all will have this function, you need one that can show frequency or something like (may have PWM in its setting), you could attach this across the actuator (ie with it all plugged in), only easy way is with sharp probes, a bit of info below might be useful

https://www.fluke.com/en-gb/learn/bl...ure-duty-cycle

You mention your engine is a T3? so is it a single turbo not twin? some info from wiki, below (cant believe how many versions there have been...)

https://en.wikipedia.org/wiki/Volvo_D5_engine