Fault Codes P046C00, P245700 (and P164B00?)

[RobbieT]

Hi, my first post, I have a T6 102bhp LWB hightop converted into a campervan. I am not a mechanic but have enough knowledge to be wary of spending money at garages unnecessarily.
The first two codes above appear to relate to EGR. The final code oil pressure switch faulty operation…?
I was alerted to the above by the EML coming on intermittently, rarely on starting but does come on virtually every time the vehicle is used And revs are limited to approx 2.4k. When this happens it usually stays off for the rest of the journey/day after turning the ignition off and back on.
The EGR valve and cooler were replaced approximately 30K ago and a split metal EGR pipe a couple of K ago. We do approx 60% of our miles on motorways and have increased the frequency of holding it in fourth gear at 60mph to try and trigger the DPF.
Our garage has suggested replacing the whole EGR system as recommended by VW.
Any thoughts and ideas greatly appreciated.

 

[mmi]

T6 102bhp

Please clarify which engine exactly (from sticker under dash by steering column) - CAAB or CXGB (AdBlue)?

revs are limited to approx 2.4k.

Please clarify - while driving or at a standstill?

The final code oil pressure switch faulty operation…?

Please have a look at

[T6_measured] 01-Engine - Oil pressure switches & Oil level sensor

For future reference. Applicable to T6 EU6 engines. Oil pressure switch - F1. Switch pressure 2.3 to 3.0 bar Oil pressure switch for reduced oil pressure - F378 (919-040) Oil pressure regulating valve N428 (906-030) References: Workshop Manual Transporter 2016- Engines: CXFA, CXGA, CXGB...

www.t6forum.com

 

[RobbieT]

Please clarify which engine exactly (from sticker under dash by steering column) - CAAB or CXGB (AdBlue)?


Please clarify - while driving or at a standstill?


Please have a look at

[T6_measured] 01-Engine - Oil pressure switches & Oil level sensor

For future reference. Applicable to T6 EU6 engines. Oil pressure switch - F1. Switch pressure 2.3 to 3.0 bar Oil pressure switch for reduced oil pressure - F378 (919-040) Oil pressure regulating valve N428 (906-030) References: Workshop Manual Transporter 2016- Engines: CXFA, CXGA, CXGB...

www.t6forum.com

Many thanks for your sopport,

It is a CXGB AdBlue engine.
Revs feel limited while driving. Since sending the last message I am less certain about this, it has revved to 3k, I don’t tend to go beyond this normally but that is where I hold it in fourth to trigger the DPF cleanse, however if the EGR is clogged enough I don’t know if this helpful or not!
Any thoughts appreciated.

Rob

 

[mmi]

It is a CXGB AdBlue engine.

Thanks for the clarifications.

Here are my thoughts:

P046C00 - I would put this on hold for now. More to read about here:​

EGR Valve Self Test Procedure (IDE00242)- P046C?

So, I've been getting the all too common P046C fault code along with P2457 (Insufficient EGR Cooling Performance). Neither alone will flag a check engine light but combined they sometimes seem to. To try to figure out what is going on, I ran an EGR Flow test on VCDS using instruction from @mmi...

www.t6forum.com

P245700 - Exhaust Gas Recirculation System - Insufficient Cooling Performance​

That's a new one on the Forum. Note: it's not insufficient exhaust flow!

Here is my guess to start looking into this:
CXGB engine has a dedicated electric pump to circulate coolant through EGR cooler. I would check that the pump actually works - just thinking if it's partially jammed - but not enough to trigger a pump fault.

Would be an easy and simple measuring task for VCDS diagnostics tool . Possibly related measurements posted here (also a copy attached) - see the blue curve for the cooling performance (from 200 to 1100 seconds) vs. hot exhaust entering the cooler (red curve):

EGR Valve Self Test Procedure (IDE00242)- P046C?

One more thought: if you have a carista or some other decent OBD dongle I would set up a dashboard to graph IDE07756 and IDE07757 either from Car Scanner (iOS, Android) or Torque (Android). That way you could see them on the phone during driving and maybe catch if there’s any discrepancies, no...

www.t6forum.com

 

[RobbieT]

Please clarify which engine exactly (from sticker under dash by steering column) - CAAB or CXGB (AdBlue)?


Please clarify - while driving or at a standstill?


Please have a look at

[T6_measured] 01-Engine - Oil pressure switches & Oil level sensor

For future reference. Applicable to T6 EU6 engines. Oil pressure switch - F1. Switch pressure 2.3 to 3.0 bar Oil pressure switch for reduced oil pressure - F378 (919-040) Oil pressure regulating valve N428 (906-030) References: Workshop Manual Transporter 2016- Engines: CXFA, CXGA, CXGB...

www.t6forum.com

Please clarify which engine exactly (from sticker under dash by steering column) - CAAB or CXGB (AdBlue)?


Please clarify - while driving or at a standstill?


Please have a look at
[URL unfurl="true"

Please clarify which engine exactly (from sticker under dash by steering column) - CAAB or CXGB (AdBlue)?


Please clarify - while driving or at a standstill?


Please have a look at

https://www.t6forum.com/threads/t6_...ressure-switches-oil-level-sensor.29978/[/URL

http://

I just started using an OBD 11 and...reciate hearing experiences/opinions on this.

 

[RobbieT]

Fault Code - Intermitant P046C00 EGR Sensor “A” Circuit Range/Performance
Started using an OBD 11, I now have this code and description show as an intermittent fault.
I would appreciate hearing experiences/opinions on this.
NB Code P245700 has disappeared