Exhaust System light coming on in dash - P26AB code Carista

W

whodat

Senior Member
T6 Guru
Hi,
Only had the spaceship for a couple weeks and is under VW warranty (whatever that means) but the orange (picture of an engine, but this is what it says in the manual) 'Exhaust System Light' came on in the dash today.
Plugged in the Carista which picked up the following error:

P26AB

Engine:
38704 - Engine Coolant Bypass Valve "A" Stuck/Open

Can't seem to find anyone else having this code on the forum but just in case.... Is it safe to just delete the fault code and see if it comes back, or is this a phonecall to the dealer?

2022 plate - T6.1 / 6 gear manual / 150psi / t30 / <20k miles on clock

It has already been back to them once for some minor non-engine bits and they gave it a courtesy oil/filter change also.
Thanks.
 
Just an update in case anyone else has the same.

A few days ago rang VW Assist who asked if it was running roughly - if it wasn't then they won't have a look at it. Seems it started 'running roughly' for a few seconds so they grudgingly sent someone out.

The VW Assist guy came to look at it and said he didn't know why they argued the case as an engine light should always be looked at and, by the way, this error on this van won't make the van 'run roughly' - so oops (my imagination runs wild sometimes). He said they have been getting a few similar cases. Just run it and watch the oil/engine temps - just in case.

Booked it in with local VW dealer (14 days wait) but they obviously wouldn't commit to whether it was still ok to drive.
A few days later and after a half hour spin, light has gone out again.
I'll give it a couple days then if light stays off, I'll cancel the appointment.

Will update if any updates.
 
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Mine has just done exactly the same, with the same code from Carista the stealership cant get me till 15th April, been doing some reading and apparently this isn't a recall issue, but there has been a "common fault" bulletin for this.
 
As said, is quite a common issue as of late.

Caused by the coolant bypass valve, which is located on the passenger chassis leg - in front of the gearbox.

Usually just a replacement valve required.
 
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My engine warning light switched itself off a couple of days ago, but the fault was still there with Carista.
So - I reset the fault to give it a couple of days in case it came back with the hope I could cancel the appointment.
Anyway - that same day after a little drive, Carista showing a new but similar fault P26B1, so will keep the appointment and hope they can do it in a day as had planned a nice trip out the day after.

On a small run (45min) and driving carefully, oil temp gets up to about 97C so not a problem at the moment.
Would think over 115C might make me pull over for half hour.
I'll post back after the appointment in a week. Could you also keep us all updated?
Good luck.
 
"common fault" bulletin

Where did you find that one?
It would be worth having a look see as to what to look out for after this one!

Cheers
 
Just a quickie update.
Took van into main dealers and got it back the same day with a new coolant valve and washed bodywork.

Hopefully, that is that and hopefully you get the same result.
 
It sometimes was on, and sometimes off. Might have depended on which error was showing at the time but I don't know for sure as there were 2 main errors - P26AB (warning light on) which came up first, then a few days later, P26B1. (P26 points to the valve 'A' and the rest of the code might have meant stuck shut or stuck open so it also might have meant it only came on when warm/cold/hot depending on whether it was stuck open or shut). It really did seem random as to whether the warning light was going to accompany me on a journey each time.
I know - not very helpful, but I checked the Carista minutes before taking it in and the error was still there along with the warning light on the dash and quite a few other errors which I didn't have enough time to check but some seemed to be indicating a warning of the warning lights on the display - which I assumed might be showing up a warning of a warning.
Haven't checked the Carista since the repair but engine light is off now. Trying not to check the Carista as ignorance really is bliss, but if you would like me to check - I will.

The workshop did tell me they have had to do a few of these recently - so could it possibly be something to do with a software update? Just a guess as you wouldn't expect 1 year old vans and 6 year old vans to suddenly start coming up with the same faults at about the same time.
 
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@whodat no need to check again, I've just started mine up and the lights back on ¯\_(ツ)_/¯, I did have a software update on mine last year, so it look like a replacement valve for me as well
 
If it is under warranty just get it done.
Haven't got any idea how much it costs if it isn't. If it is any guide - it took them up to 6 hours to do it. (Don't know if they had a whole team of people on it or if it was the trainee though.)
Let us know how it goes. Good luck.
 
Went to go to the dealers and lights gone off this morning, after waiting over two weeks to get an appointment.. "can do anything as it's showing no fault " frustrated is a bloody under statement..
 
That is bullshit - the fault will be logged in the system in the van.
It has the date, time, speed, and a few other measurements all logged.
Get yourself a Carista - once you've forked out for it you don't have to pay anything else (unless you want to reset warning lights or play with some of the settings - but careful here as I managed to bugger up things like folding mirrors. First month is free though.). It will show you the error.

Which dealer was that? Name and shame. If they aren't even plugging their computer in to check the error - that is a cop out.
Next time the light comes on - ring VW Assist. Tell them the engine is running roughly and they will send someone out.
The person who turns up will log the fault and that will be on the VW system so you can defo get it looked at by a dealer.
 
More likely that it’s run through a test plan, with no fault.. rather than there be no fault logged.

This is we’re most dealers / techs should use common sense, especially if they’re seeing the fault becoming a more common occurrence.

Wood for the trees comes mind..
 
That is annoying - would expect more for a 'high end' vehicle.
All dealers are not created equal.
Would it be rude to start a thread with recommendations of dealers (or non-recommendations?)
 
And unbelievably the bloody light came back on in the afternoon ran Carista and it gave the bypass valve stuck open fault,

Rang the dealer (Motus Commercial In Stoke) and it's going back in
 
Good luck. As I said before, my light went on and off at random but the fault was still logged. Let us know how it goes.
 
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