[FONT="][h=1]OBDII diagnostics. Trouble code definition for code P20B9. Causes of error P20B9I have been reading around the forums about the p20b9 code. The dealership is telling me its the glow plug module and it needs to be replaced, and of course it's not covered under the warranty. From what I have seen here most people are having their reservoir or tank heater replaced with this code? What am I missing here?
Also, has anyone ever changed a glow plug module out?
2014 Gen1 59k
Well if this is the case and the DEF tank heater is controlled and powered by the Glow Plug Module then the tech would have tested the heater circuit with an ohm meter and must have determined that the heater resistance was in spec. That would leave the Glow Plug Module as a source of the fault or a loose/open connection between the two. If they tested right from the Glow Plug Module then that only leaves the module as the problem.glow plug module provides the voltage for the def heater when prompted by the pcm
Good luck getting this sorted out. Please keep us posted.I was thinking the same thing. I've called Chevrolet regarding this dealership and the way they have treated my wife while I was at work, and them performing maintenance on my car without authorization and trying to charge me for it. They are terrible.
Wow. Working with a dealership like that is very painful. Throw logic and reasonableness out the window. Did you ask them if they've talked to GM TAC? (I'm not clear if they talked to TAC or customer service from your post).A little update for everyone here. After fighting with Chevrolet for 3 weeks they finally got the dealership on the phone. Now the dealership is claiming p20b9 is for the glow plug module and not the tank heater. They offered a free diagnostic and if the code comes up as warranty work they will perform it, and yes you read that correctly. They are claiming p20b9 isn't the reductant tank heater. Now you see what I am working with here.
It's very nice to hear this has a happy ending! Thanks for the update.It's done. They did another free diagnostic, admitted I was right, and they were wrong and replaced the tank. They also refunded me my original diagnostic fee. Took weeks of fighting but it was worth it.