EGR Sensor 'A' (EGR Sensor '1')

[Gordycol]

Hi there from not-so sunny Cornwall atm.
Can any of you good people shed the light on this, I have seen it mentioned on previous posts but it never seems to get answered:
I have a fault code P046C00 EGR SENSOR 'A" (1) My van It is not in limp mode and seems to be driving fine but can anyone just tell me where to find this sensor please so I can check the wiring etc?
2017 (67) 2.0 TDi Engine CXGB 75kw
A photo with a pointy thing would be great but absolutely any help would be really appreciated
Many thanks

 

[Dellmassive]

possibly EGR cooler needs flushing / replacing.

are you getting insufficient flow codes?

go any pics?

 

[Gordycol]

Thanks for the reply, yes the egr has been flushed and is like a new pin inside (45k miles) it’s just that I know where the other sensors are on it (2&3 or B&C) but I just don’t know what Sensor ‘A’ or ‘1’ refers to? No one seems to know - tis very elusive!! I’ll try and get some pics sorted anyway and get back

 

[LambethBoy]

Looking for this too!
Did you find it??

 

[n10n]

Looking for this too!
Did you find it??

I think the answer is within your freeze frame - EGR valve specified value differs from it’s actual value. Probably means the valve is sticking at least partially.

See thread EGR Valve Self Test Procedure (IDE00242)- P046C?

 

[LambethBoy]

I think the answer is within your freeze frame - EGR valve specified value differs from it’s actual value. Probably means the valve is sticking at least partially.

See thread EGR Valve Self Test Procedure (IDE00242)- P046C?

View attachment 231037

Is there a simple cleaning solution to this or am i looking at a new egr?
Will look at thread

 

[n10n]

Is there a simple cleaning solution to this or am i looking at a new egr?
Will look at thread

Flushing with varying results and longevity is common, just search the forum. Typically it’s made as a response to insufficient flow code though.

I think what happens is that first EGR valve fails to close completely. Then, especially during regens moist sooty exhaust gets through EGR cooler as the valve does not stop the flow as it should. The sooty exhaust eventually ends up clogging the cooler which then leads to insufficient flow code.

There is not, as far as I know, conclusive evidence on when exactly EGR should be changed or if a flush could help. But as the problems have started they’re just not going to go away either.

 

[Gordycol]

Hi there again, thank you all for all of the info, I have found out that EGR Sensor 1 (or A) refers to the EGR Valve itself as n10n rightly said. I unplugged it from the top, rechecked and it came back with EGR Sensor 1 connection problem. As in LambethBoy's diag it looks like I'll have to try and free up my valve. seems incredible at only 45k but it is what it is.
Thank you

 

[amv]

Hi there again, thank you all for all of the info, I have found out that EGR Sensor 1 (or A) refers to the EGR Valve itself as n10n rightly said. I unplugged it from the top, rechecked and it came back with EGR Sensor 1 connection problem. As in LambethBoy's diag it looks like I'll have to try and free up my valve. seems incredible at only 45k but it is what it is.
Thank you

I've had this fault for more than 20k km so far I haven't noticed anything strange. There are 3 options, change the valve, clean it, or leave it until something doesn't work correctly.
The problem. Cleaning takes as much time as changing it, and if you clean it and it still goes wrong. Well, you have to spend time on labor. Again.

 

[Gordycol]

I've had this fault for more than 20k km so far I haven't noticed anything strange. There are 3 options, change the valve, clean it, or leave it until something doesn't work correctly.
The problem. Cleaning takes as much time as changing it, and if you clean it and it still goes wrong. Well, you have to spend time on labor. Again.

Ahh Ok, is it the same symptoms? Mine is showing a steady amber EM light and a flashing glow plug symbol which is impossible to clear, the annoying thing is it is driving superb with absolutely no issues. If it wasn't for the MOT I'd be happy leaving it for a bit. I've bitten the bullet now and bought a new EGR from VW, I'm halfway through fitting it (absolute PIG!!) I'll let you know how it goes, tbh I'm not holding out much hope tbf

 

[LambethBoy]

Have found this on another thread,

Understanding VCDS faults

Hello Can any one shed Light on my latest scan Please, Friday,23,June,2023,18:15:20:49226 VCDS -- Windows Based VAG/VAS Emulator Running on Windows 10 x64 VCDS Version: 23.3.1.0 (x64) HEX-V2 CB: 0.4631.4 Data version: 20230421 DS346.2 www.Ross-Tech.com VIN...

www.t6forum.com

Apparently... "According to VW TSB/TPI fault code P046C alone and no emission light on dash means no repair is needed."

I think the answer is within your freeze frame - EGR valve specified value differs from it’s actual value. Probably means the valve is sticking at least partially.

See thread EGR Valve Self Test Procedure (IDE00242)- P046C?

View attachment 231037

 

[n10n]

Completely agree not an acute issue. I would suggest plotting EGR test as in thread EGR Valve Self Test Procedure (IDE00242)- P046C? - that will show how well (or not) the valve obeys. I like to think this as an early warning / canary type DTC.

 

[GavMc P11GT]

Hi so been having intermittent EGR issues on my CXGB the fault shows more or less every time I scan the engine module and maybe every 20th journey I will have the glow plug light flashing where the only remedy is clearing via vagcom.

See the fault below:

About a month ago I removed the EGR expecting it to be all coked up and to my surprise there was very little coking the cooler was pretty much clear!

However the valve was solid the plunger wouldn’t move I soaked it in release oil and got it free’d off today we got the curly glowy light on again so have checked the plunger and it seems free I’ve done a egr test in adaptations and it comes back clear so I don’t get why it’s coming up with this fault any ideas before we bite the bullet on a new one?

On a plus note it’s now possible to buy the sensor end without the cooler for a third of the cost of a brand new full assembly.

 

[GavMc P11GT]

Ahh Ok, is it the same symptoms? Mine is showing a steady amber EM light and a flashing glow plug symbol which is impossible to clear, the annoying thing is it is driving superb with absolutely no issues. If it wasn't for the MOT I'd be happy leaving it for a bit. I've bitten the bullet now and bought a new EGR from VW, I'm halfway through fitting it (absolute PIG!!) I'll let you know how it goes, tbh I'm not holding out much hope tbf

Did the new EGR solve your problems?

 

[Gordycol]

Did the new EGR solve your problems?

Did the new EGR solve your problems?

Hi Gav, well I'm not sure tbf but my problem is now solved. I fitted the new EGR , cleared the codes and the flashing glow plug and 'orange' eml were straight back on, well gutted. It still said 'soot bank' aswell on the reader although I had tried numerous DIY spray cleaners for it. I decided to bite the bullet had the DPF cleaned professionally by some chap who specialises in it (took it off, put into special tank and blasted thru). it was well worth the £350, all my warning lights have gone and the van is driving superb, so much better that before but I hadn't noticed the gradual drop in performance. The upshot is I am not 100% sure if the DPF clean would've fixed it on it's own as I had previously renewed not only the EGR valve but the MAF sensor aswell trying to get to the bottom of it, but If me and my wallet went back in time I would start with the DPF I think!!

 

[n10n]

today we got the curly glowy light on again so have checked the plunger and it seems free I’ve done a egr test in adaptations and it comes back clear so I don’t get why it’s coming up with this fault

Seems there still is difference between commanded and measured valve position - hence the DTC. So either

• the movement is not completely free under all conditions - temperature, pressure, rate of change etc
• the valve actuator does not do what it's supposed to do under all conditions even if the plunger would be able to move
• valve position measurement reports invalid values (unlikely, raw voltage seems to correspond to measured position)

 

[GavMc P11GT]

Hi Gav, well I'm not sure tbf but my problem is now solved. I fitted the new EGR , cleared the codes and the flashing glow plug and 'orange' eml were straight back on, well gutted. It still said 'soot bank' aswell on the reader although I had tried numerous DIY spray cleaners for it. I decided to bite the bullet had the DPF cleaned professionally by some chap who specialises in it (took it off, put into special tank and blasted thru). it was well worth the £350, all my warning lights have gone and the van is driving superb, so much better that before but I hadn't noticed the gradual drop in performance. The upshot is I am not 100% sure if the DPF clean would've fixed it on it's own as I had previously renewed not only the EGR valve but the MAF sensor aswell trying to get to the bottom of it, but If me and my wallet went back in time I would start with the DPF I think!!

I’m on 110k think a dpf clean etc may be a good call tbh will look into it cheers!

 

[DXX]

Hi Gav, well I'm not sure tbf but my problem is now solved. I fitted the new EGR , cleared the codes and the flashing glow plug and 'orange' eml were straight back on, well gutted. It still said 'soot bank' aswell on the reader although I had tried numerous DIY spray cleaners for it. I decided to bite the bullet had the DPF cleaned professionally by some chap who specialises in it (took it off, put into special tank and blasted thru). it was well worth the £350, all my warning lights have gone and the van is driving superb, so much better that before but I hadn't noticed the gradual drop in performance. The upshot is I am not 100% sure if the DPF clean would've fixed it on it's own as I had previously renewed not only the EGR valve but the MAF sensor aswell trying to get to the bottom of it, but If me and my wallet went back in time I would start with the DPF I think!!

At 170K Km I’d say your EGR was toast, you did well to get that far with it.

 

[Gordycol]

I’m on 110k think a dpf clean etc may be a good call tbh will look into it cheers!

Yeah keep me posted, id like to see if it cures yours, good luck

I’m on 110k think a dpf clean etc may be a good call tbh will look into it cheers!

Yeah keep me posted, id like to see if it cures yours, good luck

 

[doningtonphil]

Hello all.
Picked up this thread as I have a CXGB engine (2018, 156k miles) with the insufficient gas fault code, with 'engine' light on.
Mentioned to my friend who is a mechanics lecturer and said he would be keen to diagnose and fault find other issues, and he would get his mate who is a lead technician at a VW van centre to help him.
Even go so far as taking the cooler out and looking inside (with a new one on standby - on that score, do TPS accept parts back that have not been unpacked/fitted?)
Of course, I am not going to turn an offer like that down!!!!!!
Interesting to read about potential other causes as it seems the 'insufficient gas' code is triggered by a calculation from all sorts if inputs rather than just a yes/no from one single source.
@GavMc P11GT - any joy with the dpf clean?