Member Since: 29 Aug 2022
Location: Dublin
Posts: 21
P0048-00 - Turbo/supercharger boost control solenoid - error
Hi all
I seem to have created new error that's picked up on my IIDTool since removing and cleaning out the y piece and egr pipes last weekend....
P0048-00 - Turbo/supercharger boost control solenoid - circuit high (2B).
Tried the following tasks to date to try and resolve the issue:
* New right hand drivers side Valeo EGR replaced.
* Two of the three turbo pipes replaced either side of the
intercooler. Also checked small pipe nearest to turbo
and it's secure and not cracked.
* Swapped out the MAP sensor, swapped out the air
intake body, swapped out the y-piece electronic throttle
body.
* Blanked both EGRs with blanking plates.
*. Checked the Turbo actuator to ensure its free, and it
was, & oiled up well with WD40 whilst in there.
* Sprayed brake cleaner onto the seals of the y-piece with
the engine running- but didn't hear any change in engine
noise to indicate an leak onwards into the manifold,
suggesting the y-piece seals are OK.
* Removed the fuse board in the passenger side well,to resolve a leaking sunroof pipe, and whilst out I inspected it all for any corrosion and checked all fuses, all were fine, and board re-fitted fine, no new faults created after that job.
NOTE:
The P0048-00 turbo error only occured since cleaning up the y- piece manifold and egr pipes going into the manifold.
Tried a short drive around the block last night and lots of white smoke ( prior to blanking the EGRs). So I didn't push it as I didn't want to cause more issues with the engine.
P0408-00 - Exhaust gas recirculation sensor B circuit high (2B)
P0048-00 - Turbo/supercharger boost control solenoid - circuit high (2B)
Last edited by GLEOIRL on 14th May 2023 2:58 pm. Edited 2 times in total
27th Apr 2023 2:51 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
Hi and welcome.
You could try freeing up the turbo actuator rod as it may be sticking causing P0048-00.
The solenoid is hidden behind the turbo but the rod can be accessed from the passenger wheel well once the heat shields are removed. If you do a search on here you will find the info and pics as there is loads written on it.
If you are removing/replacing the EGR's you can get a better view of the turbo solenoid and its connector from above once the EGR is out. Incidentally, those replacement EGR's won't last and the OEM's are not much better. You'd be better off to blank them with a kit (or make it yourself) and then apply a patch via your GAP IID from BAS remaps!
There's plenty written on this subject too if you use the search function.
Good luck yµ (idµ - eAµ) ψ=mψ
27th Apr 2023 4:17 pm
Beno2
Member Since: 18 Apr 2009
Location: SE
Posts: 987
Split turbo hoseD3 HSE
27th Apr 2023 8:58 pm
GLEOIRL
Member Since: 29 Aug 2022
Location: Dublin
Posts: 21
Actuator arm seems to be fine, sprayed it up anyway and spent some time jiggling it back and forward to ensure there was no sticky point in it's movement.
Click image to enlarge
Click image to enlarge
No joy either on the hoses, but replaced 2 of the easier ones of the 3 anyway, as they were quite soft and probably the original ones. The 3rd one seems to be intact, so I'll leave it be for the moment.
I'll concentrate on the electronic throttle housing seals next, then the various sensors as I don't believe it's the turbo itself as it was fine until I did the EGRs and pulled the electronic throttle off too to clean it
out.
Spotted that the diesel heater exhaust is also broken within the wheel arch area...another job for the list.
12th May 2023 11:20 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
Looks like someone might have placed a jack in the wrong place and crushed the webasto exhaust.
P0048-00 refers to the electrical side of the turbo solenoid actuator, hence the need for freeing up the
rod and hopefully the vanes in the turbo.
Now that you have freed up the rod give her a motorway blast and that should burn away any carbon on the vanes. This often happens if used regularly in slow moving traffic, or a persistently low speed driving style. A split hose won't cause this fault code but it's no harm to renew them given her age, especially the long hose from the intercooler to the intake plenum.yµ (idµ - eAµ) ψ=mψ
13th May 2023 1:38 pm
GLEOIRL
Member Since: 29 Aug 2022
Location: Dublin
Posts: 21
Click image to enlarge
Click image to enlarge
Any idea where the B end of the electrical solenoid wiring terminates, and if there are any tests that can ele trically check that wiring?
I can just about see the block terminating on the turbo and it seems to be seated in fine, but it's just about touchable/ reachable from within the wheel arch.
.
Are there any key indicators from within the IIDTOOL to look out for that may highlight / pin pint the issue?
I thought blasting it down the motorway without the turbo functioning might do more harm than good?
Click image to enlarge
13th May 2023 1:58 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
Well looking at that lot there are three things that immediately jump out and are clearly not right.
One is the MAF signal frequency which at idle speed (770 rpm) should be in the region of 15 to 19 g/s.
The fact that it is so low at 4 g/s would suggest there is a very big air or gas leak in the intake side as there obviously very little air been drawn in through the MAF.
The second is the idle speed. I'm assuming you had to keep the throttle partially pressed to stop her from stalling (1208 rpm) If not, that idle speed is way too high. Check all the intake pipework and the throttle body seals (Y piece) and eliminate that intake leak. You can spray a tiny sip of brake cleaner on the Y piece seals, if the engine note changes that's where your leak lies, or at least one of them. It would be prudent to blank the EGR's rather than renewing them as you're going to be back in there again pretty soon.
In any case you need to blank them now temporarily at least to eliminate the possibility of excessive gas entering the inlet manifold which has a high likelihood.
Thirdly, the boost pressure adjustment should be around 87% but this might right itself once the air flow returns to normal values, ditto for the injector balance. Sort out the EGR/intake side and once you see the idle at 770 or thereabouts with a MAF value of 15 to 19 g/s you should be OK. Remember though if there is an EGR stuck open you will be filling the intake with burnt exhaust gasses!!
Leave the wiring alone, sort out the obvious issues first as per above. That connector on the solenoid rarely if ever causes an issue, so don't go making more trouble than you already have. yµ (idµ - eAµ) ψ=mψ
13th May 2023 3:52 pm
GLEOIRL
Member Since: 29 Aug 2022
Location: Dublin
Posts: 21
Super informative post reply PROFSR G, many thanks.
I got a 2008 donor parts vehicle from a farmer today so I'll swap out the map sensor first, and then follow through on the rest of your suggestions. Hopefully it is just a seal leak somewhere or the MAP sensor.
13th May 2023 5:16 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
Not the MAP, the MAF but you should clean the MAP as well as it's likely to be clogged from EGR gasses fouling your engine internals. DO NOT poke anything into it, just use brake cleaner or carb cleaner otherwise you will destroy it.
From the data you provided you have either air or gas entering the the manifolds upstream of the MAF. You need to sort this or you're on a hiding to nowhere.yµ (idµ - eAµ) ψ=mψ
13th May 2023 5:23 pm
GLEOIRL
Member Since: 29 Aug 2022
Location: Dublin
Posts: 21
Swapped out (known working parts from a 2008 D3 donor vehicle).
- y-piece throttle housing
MAF and MAP,
intake box, and yet the fault persists.
MAF frequency number has improved, now 17 g/s
Next step will be to make EGR blanks tomorrow and see if that helps.
Lost after that though as the turbo pipes are new as of last week anx the actuator is free as a bird with no resistance.
Click image to enlarge
13th May 2023 7:56 pm
Prette
Member Since: 16 Mar 2020
Location: Previously Stoke-ST4 (pre-pandemic), Mostly The Hague (NL) partially Lyngby (DK) certainly somewhere
Posts: 160
I was going to suggest the EGR blanking, however, you will only notice performance improvement. Blanking EGR will most likely throw some error as well.
Firstly, check whether your EGR is stuck open or close. Sometimes, a good on the gas will restore correct state (I know I am risking to be banned or crussified here - but I did so years ago and got the EGR restored simply having a fat heavy foot on the gas. Up to you then)
Blanking EGR temporarily is easy with a 5 cent euro coin.
13th May 2023 8:08 pm
GLEOIRL
Member Since: 29 Aug 2022
Location: Dublin
Posts: 21
Tried the following tasks to date to try and resolve the issue:
* New right hand drivers side Valeo EGR replaced.
* Two of the three turbo pipes replaced either side of the
intercooler. Also checked small pipe nearest to turbo
and it's secure and not cracked.
* Swapped out the MAP sensor, swapped out the air
intake body, swapped out the y-piece electronic throttle
body.
* Blanked both EGRs with blanking plates.
*. Checked the Turbo actuator to ensure its free, and it
was, & oiled up well with WD40 whilst in there.
* Sprayed brake cleaner onto the seals of the y-piece with
the engine running- but didn't hear any change in engine
noise to indicate an leak onwards into the manifold,
suggesting the y-piece seals are OK.
* Removed the fuse board in the passenger side well,to resolve a leaking sunroof pipe, and whilst out I inspected it all for any corrosion and checked all fuses, all were fine, and board re-fitted fine, no new faults created after that job.
NOTE:
The P0048-00 turbo error only occured since cleaning up the y- piece manifold and egr pipes going into the manifold.
Tried a short drive around the block last night and lots of white smoke ( prior to blanking the EGRs). So I didn't push it as I didn't want to cause more issues with the engine.
14th May 2023 2:52 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
If you still have the shields off ask someone to switch off the engine and you should be able to see the rod moving through it's cleaning cycle. You should also be able to hear it "clack" "clack" as it reaches it's ends of travel. This is important, and you need to satisfy yourself that the solenoid motor is working and the arm is moving fully through it's cycle. Beyond that, you could try a fuel additive/ VGT cleaner and see if that helps release any build up of carbon on the VGT vanes.
Has the injector balance settled to a more equalised level or is it still the same as you posted earlier?
Are you still seeing white smoke now that the EGR's are blanked?
Are there any signs of a leak on the intercooler? (wet spot!)
Is there a crack in the manifold/s?yµ (idµ - eAµ) ψ=mψ
14th May 2023 4:07 pm
GLEOIRL
Member Since: 29 Aug 2022
Location: Dublin
Posts: 21
Hi Profsr G
Funny you should say that, as I don't think the old familiar click clack sound of the start up sequence is there from the turbo solenoid, it's more that I can hear the solenoid come in and it almost sounds like it's going through the motions,/ sequence minus the click/clack - disconnected from the actuator perhaps?
I didn't take it for a spin after blocking the EGRs this morning once the engine fault was still showing, as I am trying to minimize use until the fault is cleared, nor did I check the balancing since on the IIDTOOL.
Last edited by GLEOIRL on 15th May 2023 11:50 am. Edited 2 times in total
14th May 2023 8:57 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4651
"Video unavailable" Private!!
Just get inside the wheel arch and have someone start and stop the engine a couple of times.
You will see the rod move away and towards you as the solenoid goes through it's cycle.
It could just be that it has become detached. You can get a look at it from above as well although it's
obscured by the EGR, an inspection camera might be helpful if you are unsure.yµ (idµ - eAµ) ψ=mψ
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
on the gas will restore correct state 
(I know I am risking to be banned or crussified here 
- but I did so years ago and got the EGR restored simply having a fat heavy foot on the gas. Up to you then)
