AD BLUE FAULT

[Evilhomer1942]

Guys, seemingly a relatively common fault - 2016 B9 A4 tdi with the P20E8 adblue fault. (Reductant pressure too low) which i interpret as the ad blue isn't getting pumped in!
Local garage saying the diagnostics he has can't confirm whether it's the pump or the control unit at fault.
In any case both parts are extremely expensive even for him to replace.
Let alone the stealership.
Any advice, recommendations to keep the costs down appreciated.

 

[spartacus68]

Not sure you have much choice in this. Car needs scanned with VCDS to pull codes. A main dealer will take £100+ for the pleasure, or see if a forum member near you can do it for beer tokens.

The adblue pump is well documented, and I don't know if it's subsequently been revised design wise, because I was going to suggest a second hand one from a breakers, but maybe that's false economy. How don't know how much labour is involved or if it's DIY job. You may need VCDS to reset or calibrate.

 

[WesT-gefül]

Guys

Any advice, recommendations to keep the costs down appreciations.

Did you buy from a dealer or private person. Would be nice if they could do a courtesy repair. Just explain that it seems there is a issue with these pumps. I had mine done as a warranty repair. (Sorry)

Here is the post I made warning people as nothing came up on the dash.

https://www.audi-sport.net/xf/threads/adblue-pump-“pressure-too-low’-a4-2-0-tdi-b9.374419/

** The Tapatalk app doesn’t like links so I’ll screenshot the link. **

 

[Toonsoldier91]

Silly question but is your adblue low? I had the pressure warning come on and I was down to 200 miles left refilled it and it never come back. Just a idea

 

[Garrett 69]

Cheap option? Disable the adblue system completely and run on HVO, emissions will plummet using HVO.

 

[L_G]

With apologies to the OP but Ad blue was one of the reasons I decided not to get another diesel car when the time came around to change having previously owned two A5 3.0 TDIs.

 

[Shock_Xe]

I removed my working adblue tank and pump. For sale if interested pm me