[m9bm]

2 weeks ago: SES light. Read code and it came up as 4BAC.
I took it to the dealer and they determined a new SCR tank was required.
I am in California and it is covered under the 70000 mile emissions warranty.
They tried to charge me $50 deductible. I argued with them and showed them page 44 of the warranty booklet.

They were astonished and apologized. $0 out of pocket.

I drove back home and parked it overnight. When I woke up, a giant puddle of DEF had crystallized on the ground and on the back of my car. It went back to the dealer and they determined that the lines were reversed!!

Now this week, I threw another SES light and the code came up as 4BCD.
I did a search and the most likely culprit is either NOX sensor or another sensor.

Are these two codes related?
Is this covered under the California 70k warranty?
Is this covered under the Gold extended warranty? ($50 deductible)

[BB_cuda]

One would think NOX sensor is emissions related and therefore 0 deductible to you. I'm no lawyer though. If you don't ask the question, the answer is always "NO".

[stevers314]

Call up the state and say "can I remove this?". If they say "no you seal clubbing oil well driller, that's a pollution device!!" then you have the answer.

[Hoooper]

If for some reason its not covered under the warranty, I would be inclined to remind them that they reversed the lines from the DEF tank which likely caused the code in the first place

[GreekboyD]

Originally Posted by Hoooper

If for some reason its not covered under the warranty, I would be inclined to remind them that they reversed the lines from the DEF tank which likely caused the code in the first place

This is how you do it.

[austinla335d]

Originally Posted by GreekboyD

This is how you do it.

You shouldn't have a problem with this. The DEF debacle was enough to put them in bad terms with you in my opinion.

[m9bm]

Great thanks!! Will update on what happens. Going into the dealer on 8/22.

[floydarogers]

Originally Posted by m9bm

Now this week, I threw another SES light and the code came up as 4BCD.
I did a search and the most likely culprit is either NOX sensor or another sensor.

Are these two codes related?
Is this covered under the California 70k warranty?
Is this covered under the Gold extended warranty? ($50 deductible)

Should be covered if under 70K.

[F32Fleet]

It's covered under OEM extended warranty for sure however they should not charge you the $50 deductible due to the fact that they probably didn't diagnosis the entire problem OR that you were just there.

[m9bm]

Great. I will make these points. Can someone briefly explain to me what the NOX sensor has to do with the SCR tank lines being swapped?

[floydarogers]

Originally Posted by m9bm

Great. I will make these points. Can someone briefly explain to me what the NOX sensor has to do with the SCR tank lines being swapped?

Well, the two NOx sensors (which are kind of pricey compared to O2 sensors fyi) are the feedback control for DEF utilization. The engine computer (DDE) runs a validation check periodically (definitely during/after a DPF regen), and will throw codes depending upon it's fault tree. Might well have decided a NOx sensor was bad if the DEF/SCR system was screwed up.

[F32Fleet]

Originally Posted by floydarogers

Well, the two NOx sensors (which are kind of pricey compared to O2 sensors fyi) are the feedback control for DEF utilization. The engine computer (DDE) runs a validation check periodically (definitely during/after a DPF regen), and will throw codes depending upon it's fault tree. Might well have decided a NOx sensor was bad if the DEF/SCR system was screwed up.

+1. I had both NOX replaced with the installation of a 2nd DEF tank and SCR catalyst. My new tank still cropped out. 3rd one installed last week.

[m9bm]

Update...

I took my car in last Friday. The problem? The BMW tech switched some of the connections. The car was ready a few hours after I dropped it off.

Is that ridiculous or what?
On the bright side, I decided to keep their 228i loaner for the rest of the weekend.

[Hoooper]

Originally Posted by m9bm

Update...

I took my car in last Friday. The problem? The BMW tech switched some of the connections. The car was ready a few hours after I dropped it off.

Is that ridiculous or what?
On the bright side, I decided to keep their 228i loaner for the rest of the weekend.

haha, he had the post sensor plugged into the pre sensor and vice versa? No wonder the DDE saw an issue, it was indicating that NOx was higher after the reducer than before

Good news that it was an easy fix, at least

[floydarogers]

Originally Posted by m9bm

Update...

I took my car in last Friday. The problem? The BMW tech switched some of the connections. The car was ready a few hours after I dropped it off.

Is that ridiculous or what?
On the bright side, I decided to keep their 228i loaner for the rest of the weekend.

Last year when I was having SCR codes, the SA said that on a previous visit the tech had installed the mixer (swirl device just before the SCR catalyst) backwards. Many of these techs don't know what they're doing.