Audi Adblue Issues - P20BD Reductant Heater Circuit - Engine light on Audi Q5 2.0L TDI

We get an Audi Q5 TDI in with an engine light on due to P20BD. With a little research and testing, we get to the root cause of the issue and get it rectified for the customer. Special thanks to ‪@Diagnosedan‬ who created www.ddtsb.com for the automotive community.

[@Diagnosedan]

I was swinging on the Sofa on your workshops background music😁 Great video Rob. Spot on Diagnostic procedure!

[@romanosautomotive]

Thanks Dan, I made it with your music tastes in mind too ;)

[@isalmankhan1]

Bravo👍, Great video Bro, this could be quite a challenge without DDTSB, but you fixed it👍 DiagnoseDan has made a huge improvement to our community by compiling all this info & making it available just few clicks away👍 Thanks for sharing Bro, Stay Safe👍

[@romanosautomotive]

Thank you my man!! DiagnoseDan is a legend!

[@martinmller3593]

Great Video. The resistance value is now added to the existing TSB and so is a link to your video.

[@romanosautomotive]

Thanks Martin!

[@Jo-hannson]

man, same issue I had a few days ago with an VW Tiguan. good work

[@DJ-tn7vj]

This is how it normally goes. We see Rob with it. Then we get jinks. Lol. Love the contents as usual. No short cuts. Keep it up Rob

[@romanosautomotive]

haha yes indeed, we are all in the same boat with all of the same problems :)

[@jeremystone6613]

Nice one Rob!

[@romanosautomotive]

Cheers Jeremy!

[@anguss-a4774]

Adblue freezes -11°C, I live in a country that doesn't ever get that cold, so the heater never comes on. So I simply cut the two wires for the heater and soldered on a 8ohm 100w wire wound resister, a bit of heat shrink, $20 worth of parts, 2 hours of time. No problems from the reductant heater system that was 3.5 years ago... Save yourself a fortune. (I have an AUDI Q5 2013 2.0L CGLC DOHC 16v Turbo Diesel)

[@chilledout8334]

Hi could you give a more detailed on how you did that ??

[@romanosautomotive]

Fair call Angus, if it works for you then great. Thanks for commenting it in case it helps anyone out.

[@3vyatarla434]

Hi you have picture where you soldered the resistor exactly

[@angusmann9849]

I have the same code and problem at the moment. So if this is the case and it isn't that detrimental to the car, is it okay to drive in the meantime if waiting for parts to get sorted or complete the same fix you did?

[@shanaybhem5783]

Could you give us a picture of where you did this

[@UnreachableMike]

In cases like this i like to make a note of the Known Good components resistance so in the future i can prove the fault before getting the part with decade box.

[@romanosautomotive]

Good call Michal, we just get lucky when it's completely open circuit!

[@saidmaelainine296]

Thank y veru much

[@Krypt0nTech]

What is the part number for the wiring harness?

[@saidmaelainine296]

Just question , if we use anti cristallisation is that will resolve to problem or we have to do what you done

[@DiegoJVilla1]

What is the part # for this part?

[@bogdanracasan6525]

Hello , so I have the same problem with my Q5 and at tha garage they told me to change all tha adblue tank . Can you , plase , tell me what did you used for your car ? The name of the product or some informations of how can I solve the problem? thank you !!

[@romanosautomotive]

Hi Bogdan, what I used is in the video. Did you watch it all?

[@boxingmafia1435]

I’m in the same position, garage told me to change the whole Adblue tank for £3K 😅

[@fimsty]

I have the same issue. We pulled the heater element plug and there was power. What would be the next thing to check?

[@TwisTeDRAMPAGE7]

How much would this cost to be done?

[@tertiusscheepers8357]

I am unable to get the heater element off the adblue pump

[@apdullahkaraca2107]

hello do you have the reference of the wiring to change? THANKS

[@apdullahkaraca2107]

hallo wat is de referentie van het blad, bedankt

[@marion1600]

nicely done! do you happen to know what is the heater element resistance value threshold? Would 2 ohm resistance trigger the circuit high fault code or not?

[@Resistance280]

Nah an ohm here or there shouldn't make much difference

[@siledascalescu8813]

Hi.white îs p20b900, p148b00 Code. Thenk you .from Rumania

[@misterq3906]

Wouldn't mapping out the adblue solve this?