Diesel Exhaust Issue

[carobin]

here's one that the experts can't seem to resolve....there is a persistent error (46C4:Reducing Agent Pressure Line Heating Activation) which I have seen some discussion here about but wanted to start a new post. My mechanic has replaced the line from the DEF tank (which has a heating element to it) and that didn't fix it. he also feels strongly that this is not related to the active tank. he is charging me to replace parts that do not fix the issue - is this standard? any suggestions on what else this could be? I want to sell this car. it has had all repairs done and this remaining check engine light will be an issue. car has 145k on it.

[ard]

1. There are, I believe, 3 heaters in the DEF/SCR system

2. Shops make a diagnosis, tell you what they are going to do- YOU approve the repairs. When they have guessed wrong, you still pay. Arguably the thinking is that it is the car's fault that it is hard to repair. they may also claim "oh, there is more than one broken part". Whatever. To answer your question, it is common.

3. So what does 46c4 mean? Is it a bad heater code? Is it an error being detected in how the SCR system detects a blockage and then activates the heater? Dunno.

FYI: https://www.newtis.info/tisv2/a/en/e...system/XOk5tV8

[carobin]

Thank. Appreciate the feedback and link to the schematics and system overview. Looks like a lot of things just waiting to brake. Now I know why my 1979 VW diesel lasted well beyond 250k miles and why most people lease the X5 for 3 years and move on. Unfortunately I didn’t.

[ard]

Originally Posted by carobin

Thank. Appreciate the feedback and link to the schematics and system overview. Looks like a lot of things just waiting to brake. Now I know why my 1979 VW diesel lasted well beyond 250k miles and why most people lease the X5 for 3 years and move on. Unfortunately I didn’t.

Ive got 101k on my 2012X5. Probably drive it for another 100, 150k.

If you bought it new, and have driven it 145k, not a bad run, correct? Should have had a few key parts replaced under warranty/recall, correct?



Now, on the other hand, if you spent $10k on a car with 130k, figuring you can pick up a 70k car for pennies on the dollar- and blithely neglected to consideer that historical costs of 1980s cars might not apply to 2010+ cars- welp, yes, that can hurt.


IMO, lots of X5 D owners that arent leasee's. LOTS.

[carobin]

Have had it since 46k miles. Through that it’s never NOT needed a control arm repair engine seems to run. Drives well when it’s fixed. I’ve had a handful of bmws Audi’s and land rovers that were never this ten permental and seemingly over designed. Fact is I’m throwing parts and this error code and no one can identify the cause and remedy. It’s a very frustrating way to accomplish transportation.

[ard]

Yes, clearly frustrating.

How many different shops have been working on this 46c4 issue?

I would assume that ISTA/Rhiengold has some tests that can be run, as opposed to just reading codes and guessing with parts.

Does your shop have the ability to run testplans?

[ard]

Edit.

Looking at the diagram again, thre are FOUR heaters.

Interestingly, TWO of them use the term "line heating". #2 is "line Heating" and #10 is "Line heating of the intake pipe in the active tank"

Did the mechanic ohm the heater element on the part he replace? Does he have the knowledge to figure out which connections to test the 'line heating' element inside the tank??

[carobin]

Thank for reviewing the diagram. I have had 2 mechanics look at it. The regular guy is send it to the dealership. Appreciate the tips and support. I’m guessing the DEF system is a ticking time bomb. I did not get anything covered under recal or warrantee in time. hopefully anyone else out there with experience around this can chime in.

[ard]

Originally Posted by carobin

. The regular guy is send it to the dealership.

Huh?

I know you think this is the cars fault, the fault of the DEF system....and NOT a problem with 'your guy' or the quality of the work they are doing.

Seems that your mechanic believes it is/was one of the heater elements, and guessed at one.

Ive explained how one can definitively check each element...rare to find a tech that does that- they have no problem replacing $2500 worth of parts and - in the process- convince you that this is ALL bmws fault. The parts they replaced that were ok, all of it.

[daytonatrbo]

Is the error description you have from the correct software?

Generic code readers tend to missdiagnose these things.

When my DPF was clogging, my generic code reader said it was an EGR fault. The correct software indicated it was “DPF ash loading”. Makes a HUGE difference in how you attack the problem, no?