Help!!! Dealer wants me to replace ECU for 2k!?

[mdm9]

Software Mods: Some feature coding from the BMW Carly App and the GTS DCT tune from Alex@Alpine.

Timeline of events:

Dec 1st - Cut out primary cats and replaced with test pipes

Dec 6th - Got a limp mode while driving, Misfire with Cut out (002B39), Misfire with emissions deterioration(002B46) in cylinders 5,6,7,8, then a bunch of other codes including Check at lower top, and I think I got the idle control valve code. Cleared the codes and it was fine.

Dec 28th- Increased Emissions light comes on. Very strange that it took this long for it to come on due to being catless. Cleared it and it did not come back for several weeks.

Jan 18th - After starting the car, I get a limp mode with 002B0D (Idle Control Valve) and 002B57. Limp mode was intermittent and occurred upon creeping at idle speeds, especially in reverse.

Jan 30th - Replaced the ICV myself, same codes came back this time also with 00A6D1 (short circuit additional water pump) and 005E19 (engine torque is not adjustable CAN).

Jan 31st - Took car into dealer.

Feb 2nd - Charged $720 to rip the intake off and diagnose by testing all the DME wiring and ICV functions, all which checked out fine. They reset the codes and reprogrammed the ECU and gave the car back to me, thinking the issue had been resolved. The BMW TSE (regional service engineer) says the next step if this didn't work is to try replacing the DME (ECU).

Feb 3rd- Limp mode already came back once, so it isn't fixed. I can shut the car off and on again and it will go away. Now the idle drops to 500 when I touch the accelerator and it seems to hesitate getting off the line. Took the car back to BMW, and they want me to pay $2200 to replace the DME, saying that they don't know what the next step is after that.


This seems like a dramatic step to me, isn't there something cheaper that we could try first??? $2200 is a lot of money especially when it isn't guaranteed to fix my problem. The closest good BMW Indy shop is 3 hours away, so the dealer is my best option, especially since they have access to the TSE's. Should I trust the TSE's opinion and pay to replace it? Could it be a vacuum/brake booster issue since the idle drops while creeping forward/backwards??

I've already thrown $650 (for the ICV) + $720 for BMW diagnosis time at the car, so I will think I would seriously consider selling the car if the $2200 for the DME doesn't solve the issue, and that's not something I want to do.

I really appreciate any input anyone can provide. If more info would help, let me know, I have some freeze frames of the engine data from the BMWCarly App - I am just dedicated to getting this damn issue fixed.

[dparm]

Is there another dealer close by so you can get a second opinion? They all use the same diagnostic flowcharts and service manuals, but maybe this dealership misread something or misdiagnosed it?

[mdm9]

Closest other one is about 2 hours away.
I cross posted this in ECU Mods, and they gave me the idea to replace my O2 sensors and fix an exhaust leak I think I may have just before the O2 sensors. I'm going to try that first I think.

[TomHudson]

Perhaps reaching out to an aftermarket tuner that designs tunes for catless or high-flow cat set-up.
They may have some feedback, or experience with what you have here.
I just find it particularly odd that this all happened days after removing the cats, and having said that, buying a new ECU and still having problems would suck!

[Locksmythe]

First, is there a guide for replacing the ICV? You said you did it yourself.

Second, if you took out the cats your sensor readings are going to throw the emissions flag unless you turn off the test through coding. It only executes the test when you drive the car the right way (slowly and under 3k rpm) which you probably never do. I could not find the instructions I had used with a search, but here is similar:

http://www.m3post.com/forums/showpos...27&postcount=7

[Killerfish2012]

Originally Posted by mdm9

Software Mods: Some feature coding from the BMW Carly App and the GTS DCT tune from Alex@Alpine.

Timeline of events:

Dec 1st - Cut out primary cats and replaced with test pipes

Next step should have been:

1. replace all four 02 sensors (the old ones won't survive being taken out and put back in).

2. Get a tune. Strongly recommend the evolve tune.

[S65B40YYC]

Originally Posted by mdm9

Closest other one is about 2 hours away.
I cross posted this in ECU Mods, and they gave me the idea to replace my O2 sensors and fix an exhaust leak I think I may have just before the O2 sensors. I'm going to try that first I think.

Subscribed. I am also getting codes/limp mode that are indicating the ECU is bad (2B55 & 2B57). I also had my primary cats removed last summer but I don't recall when this issue started happening as the car has been parked for 3 months. I was also told that some bad coding could be responsible and I did have some coding done on the car last fall.

I do have an ESS tune so I assume the tune is taking care of the CEL from the cat removal as I don't get that CEL. I have been advised to have the entire car coded back to stock and then try to reflash the ECU with the ESS software as the coding.

[jimbob123]

you've so many faults arising that's very difficult to pinpoint the issue.i would think simple and start with battery condition . also check all earths in the engine bay particularly the main strap lower down on the engine.these are all tasks you can do yourself costing nothing.
once your 100% happy reset everything and retry.
this way you have eliminated a number of items that are known to cause issues.
The dealers are only too happy to dive in at the deep end spending your hard earned cash.

[S65B40YYC]

Originally Posted by S65B40YYC

Subscribed. I am also getting codes/limp mode that are indicating the ECU is bad (2B55 & 2B57). I also had my primary cats removed last summer but I don't recall when this issue started happening as the car has been parked for 3 months. I was also told that some bad coding could be responsible and I did have some coding done on the car last fall.

I do have an ESS tune so I assume the tune is taking care of the CEL from the cat removal as I don't get that CEL. I have been advised to have the entire car coded back to stock and then try to reflash the ECU with the ESS software as the coding.

So I finally got around to dealing with this. I spoke to AJ at ESS and he said the likelihood of the ECU being bad was super slim. He asked me to start by taking the car to the dealer and to have the ECU reprogrammed back to stock and then reload any coding and software from there.

This has solved my problem for the time being with no more codes or limp mode. In the event you need a new ECU, PM me as I have a line on an used one for a fraction of what the dealer is quoting you.

[doogee]

Originally Posted by Killerfish2012

Next step should have been:

1. replace all four 02 sensors (the old ones won't survive being taken out and put back in).

2. Get a tune. Strongly recommend the evolve tune.

What? No this is ridiculous. O2 sensors are easily removable and the chances of 4 failing at once is impossible as well.

I disagree with everyones input.

Start off by getting back to stock and get it diagnosed from there. For the most part, the dealer can only do a good diagnosis on a car that has not been messed with. Especially when it comes to engine management.

Don't throw more fuel on the fire with more mods or "tunes". Work backwards.

[dparm]

Originally Posted by doogee

Don't throw more fuel on the fire with more mods or "tunes". Work backwards.

300% this.

Don't be foolish by replacing parts hoping something fixes it. Look at a BMW diagnostic flowchart and rule things out one at a time. Auto mechanic school 101.