Lemon320

Greetings fellow enthusiast,


I have a 09 Ml320 with 120k on the clock.
Had it for 13 months.


Usually when the AddBlue lights up, I top it off and the message disappears soon after.( I topped it off with 9 starts left this time) I drove around 50 miles and still there.


Went to Autozone:
I have codes
P2BA9- NOx Exceedence - Insufficient Reagent Quality
P20BE- Reductant Heater 'B' Control Circuit Performance
P20BD- Reductant Heater 'B' Control Circuit/Open




2 starts left:
This time it did not. So I read on here that I might be due to diluted Addblue. (That it is recommended to change it every 20k) So I pumped it out and put new one. ( BLueDEF from Autozone) I drove around 6 miles and message is still there.


1 Start left:
I plan on going to the dealer in the morning.
I'm from Houston, have been in Chicago for the past 3 months, any last minute tings to check or do from the brave ones that encountered such luck?


P.S. I also have the dreaded oil cooler issue that I plan on tackling as soon as im back in town.(town=tools)

N4HHE

I think the problem is that water evaporates from DEF making the concentration greater, not lesser. That one is supposed to top it off every 10k miles without respect to the current level, and therefore drain and refill every 20k to maintain proper concentration. Would seem that if one goes to the low warning before topping off then the proper concentration should be met.

Just over a year ago I was making routine trips to the dealer with CELs complaining about AdBlue injector, NOx sensor, etc. Eventually they found a bad electrical connection. And this Christmas my fuel gauge suddenly reads Empty when I know it had 10 gallons remaining. Sadly when I filled the tank the fuel gauge read Full. So I'm monitoring that situation.

Lemon320

Thank you for the reply.

Do you know wher the electrical problem was at?

N4HHE

It was said to be "in the back". The service writer said "short" but every electrical problem is a short to the non-electrical. I suspect the problem was a bad connector. And that would be an open, not a short.

Considering I now have intermittent problem with fuel gauge I'm guessing its the same old problem as before. Am told the fuel sender is under the rear seat.

jrgator

we had the same fuel gauge problem a few years ago. it would jsut go to zero, though there was fuel in it. after 3 tries the sensor fixed it along with a connector problem.

N4HHE

Yup, thats what mine did. Believe I had 8 to 12 gallons remaining having started with a full tank that morning and somewhere below 1/2 tank indicated it was suddenly zero with no "50 miles remaining" warning. Topped the tank about 100 miles later and gauge indicted full as if nothing had ever happened.

Can you elaborate? It happened 3 times and fixed itself? Or you disassembled and replaced the sender 3 times before finding a bad connection? Where was the problem connector?

I'm thinking of pulling the back seat and access panel underneath to reach the sender and simply break/make the connections to see if that will fix it. OTOH I have a scanner and intend to go out and check for codes which don't trigger the CEL. If it has fuel gauge related codes I'll let the dealer deal with it under extended warranty and get a free car wash out of it at the same time.

Lemon320

You should be able to just pull the release in the rear passenger seat and have access to the pump under the round cover.

jrgator

it took the dealer 3 times to fix it under warranty. I believe that the actual lead from the sensor was crimpted and shorted out or was making intermittent contact.

Lemon320

Update:

Dealer updated the firm ware.
Advised to replace the AdBlue tank.
Later while bringing the tank down they just manually moved the leveling sensor &wala..

3 hours of labor @ 169