Egr and oil pressure switch faults

[billybonko]

About 4 months ago my 2016 T6 seemed slow to start up one day. After that I started getting the flashing coil light come on when driving from cold, driving for 10 minutes then restarting seemed to clear it until the next day, it was pretty consistent.

Carista reported the following issues:

P0401 - exhaust gas recirculation "A" flow insufficient detected

16056 - oil pressure switch malfunction

23871 - exhaust gas recirculation.flow: insufficient detected.

A quick Google showed a guy on here with the same issue, where it requires nrw EGr and pressure switch and local garage agreed. So replaced EGR and oil pressure switch. Problem then solved and I've done 6k.

Last week started it, it took several seconds to start, and within a few minutes the coil light is on again, carista says the same faults are back.


What's interesting is that it had done the same sort of drive the day before as the last time (drove pretty hard on a long run with 4 mile hill slog at the end). Now either I'm unlucky, and have the same two components fail again, or something else is wrong which is causing them to go, or theverrors are wrong/caused by a diffeent issue.

Any ideas?

 

[billybonko]

Update: turns out that when replacing oil pressure switch, the garages supplier sent the wrong one, so they actually just cleaned the old one up and refitted. So this time around garage has replaced oil pressure switch and the faults are all gone and not recurred.

It's worth noting that this implies that the egr was never faulty in the first place.. so if you see this combo of errors try replacing the oil pressure switch first.

 

[petef]

Update: turns out that when replacing oil pressure switch, the garages supplier sent the wrong one, so they actually just cleaned the old one up and refitted. So this time around garage has replaced oil pressure switch and the faults are all gone and not recurred.

It's worth noting that this implies that the egr was never faulty in the first place.. so if you see this combo of errors try replacing the oil pressure switch first.

Hi. As this is my first post I wasn't sure if I should start a new thread or reply to this as it is so similar?
Firstly, I should say 'thank you' for all the useful info I have picked up here, a great resource.
I haven't really delved into diy maint since the days of vauxhall chevettes and cavaliers, so this T6 CXGB 2016 is quite daunting. I've not had many issues in the 6 years 35k miles but now, coincidentally(?) since a timing belt and oil change, have a flashing glow plug when cold with Carista showing the errors 15560 and 16056. My local VW specialist say it is an EGR problem but looking on here, and as for this thread, some have fixed this by changing the Oil pressure sensor for low pressure. As all is good when warmed up, I thought I'd take a punt on the oil sensor. After several attempts and reference to the manual and extracts posted here, I have found it! I think I can get an open ended spanner on it from the angle in my photo but the tricky bit may be releasing the connector! I presume there is a tab on the right angle connector to release the locking hook? The manual drawings don't show that detail so I'm hoping someone can help with a picture or what to feel for?! I can only get 1 hand in, either from the right side or from the left over the top.
Failing that I'll have to bite the bullet and go to a main dealer. Thanks in anticipation.
Pete

 

[cairn15]

Hi there, I have a similar issue to yours 2016 T6 CXGB , I have flashing em/coil on dashboard, Carista Code 16056, 'Oil Pressure switch malfunction'.
I have replaced both high, and low pressure sensors today, I managed to get a spanner onto the 'Green' low pressure sensor, at the back, and got that replaced, but it is really tight to work on. Now I have noticed a wiring bodge on the switchwires to the 'High' pressure sensor which I believe has been the issue all along, the black wire into the loom has been cut away, with the end going to the sensor being ring crimped, and using a bracket bolt, terminated to earth? , I feel as if the sensor replacements are the same path that someone else has followed, as the old sensors were not that old, has anyone else came across anything like this? Van drives perfect, no lumpy tickover etc, Thanks in advance, Garry

 

[cairn15]

Hi, ........... Success!!!! , No Flashing EML now, after previously changing both high, and low oil pressure sensors (because they are cheap anyway), and the carista fault code 16056 was still being logged, I moved on to replacing the Oil Pressure valve, it lurks behind the front engine mounting bracket, I picked up a new genuine vw oil pressure valve from ebay for £60 including the post from germany, arrived in a week, part number 04L906455B, this is a revised part slightly different to the original 04L906455A, a point to note is the electrical connector has to be turned 180 degrees, as it plugs in differently to the original part, My old pressure valve had never been replaced before, and looks it's age, externally quite rusty, when I got the old part off I definitely thought this was the culprit!
I took the van out for a good run, and it now rev's freely, and no flashing coil light, Happy Days!!!!

 

[cairn15]

new oil pressure valve

 

[petef]

For me the fix for 16056 turned out to be the brown oil pressure sensor - 5 min job compared to the few hours for each of the green sensor and pressure regulating valve!

 

[cairn15]

Lucky you M8, loving your work, that pressure valve replacement was a pain in the backside to do, they are great when their happy

 

[petef]

..at least I now have the new design of pressure valve fitted! Thanks for the tip on the connector being turned 180 deg!

 

[goldeneye243]

How easy are these to change? I've got the flashing lights...

Are there any good youtube videos to follow?

 

[cairn15]

Hi, there are 2 oil pressure sensors, low & high, the brown one at the front of the engine is the easiest takes 5mins all in. The green one in the picture above is difficult to get to, buried in the middle of the rear, of the engine block, and is hard to see (use a mirror first), even once you clear a path!, there is just enough room to get a spanner on it, and getting the connector off is a pain.
The Oil Pressure Valve lives behind the front engine mounting bracket, support the engine weight before removing the 3 bolts into the block, and the 2 bolts holding the mount onto the subframe, pretty straightforward once the mount is taken off, I'm not aware of a video showing this. Have you got a fault code?

 

[goldeneye243]

Link to thread with code

I don't suppose anyone knows the part number for the brown one or could share a link?

 

[SCTallboy21]

Hi, this forum is an absolute gold mine of information! I referred to this when I had the same problem