code 2EF4 (279B) - help the newbie!

Hi all! I'm sort of new here, been reading a lot of stuff for a while but my first post. I have been on the other bimmer forum for some time but seem to find better info and friendlier peeps here. Also it seems more of 6 series owners are on here.

So here's my problem. Got the engine light on my 2005 645 conv, increased emissions. Went to the dealer to check it out. They came back with code 2EF4 (279B). According to the BMW bulletin from April 2010 (SIB 12 15 05), 6ers made between 09/04 and 12/04 have faulty engine harness and temp sensors and they need to be replaced. Normally, they would start with replacing the thermostat but for my car production date fitting within these 3 months. The wiring harness is 'spensive to replace! I took the car in to an independent reputable shop. They suggested to start with thermostat anyway because the wiring clamps show no signs or burns or corrosion.

I'm a female and I'm always suspicious that the guys at any repair shops are trying to take advantage of me. I know a bit to know an obvious BS but on this one I'm not sure.

Please help, what should I do?

There have been several posts on this problem with 645's. I would make sure you are using good gas and run a good gas treatment through it. Check your battery. If it is old it may be getting weak which will give you codes. Thermostat is a cheap part on most cars and typical not difficult, but I've never done it on a 645. I'm not sure how a thermostat would cause increased emissions, but maybe someone else can chime in on that.

Thanks, Mulchman! The dealer's explanation is that even though the code says "Map cooling thermostat mechanically stuck," "on vehicles equipped with the N62B44 engine manufactured from 09/04 through 12/04 (mine fits right in), replace the wiring harness and the temperature sensor."

When the Indy shop ran it for codes they picked up something else about the coolant, can't remember exactly. It didn't pop up at the dealer a week ago.

Was there ever a recall or anything else to get BMW to replace the faulty engine harness? I can't find it now but seem to remember reading something about it.

More areas of concern that may or may not be related to this problem:
1. Sat radio cuts our for a sec occasionally.
2. iDrive is slow to start, delayed parking sensors, Menu activation, etc. I disconnected the blutooth but I think it started to slow things down when we paired the phones.
3. When starting from cold, it takes a couple of seconds for the engine to catch properly. I get this ch-ch-ch-chrrrrr LOL


Thanks! And please share anything you know about it!

Originally Posted by Cectra

Thanks, Mulchman! The dealer's explanation is that even though the code says "Map cooling thermostat mechanically stuck," "on vehicles equipped with the N62B44 engine manufactured from 09/04 through 12/04 (mine fits right in), replace the wiring harness and the temperature sensor."

When the Indy shop ran it for codes they picked up something else about the coolant, can't remember exactly. It didn't pop up at the dealer a week ago.

Was there ever a recall or anything else to get BMW to replace the faulty engine harness? I can't find it now but seem to remember reading something about it.

More areas of concern that may or may not be related to this problem:
1. Sat radio cuts our for a sec occasionally.
2. iDrive is slow to start, delayed parking sensors, Menu activation, etc. I disconnected the blutooth but I think it started to slow things down when we paired the phones.
3. When starting from cold, it takes a couple of seconds for the engine to catch properly. I get this ch-ch-ch-chrrrrr LOL


Thanks! And please share anything you know about it!

Well since you have an earlier production, you may want to start with checking to see if the battery was ever replaced and if so, if was coded properly to the car. You will be surprise at how power hungry this car is for electrical power. You're basically driving a PC on wheels.
On the issue of the slow iDrive response, you may also want to check and see if the dealer can provide an software update. When I had my 04, I had this done when I was trying to get MP3 playback working. It responded much better after an update.
The idea of replacing the thremastat is a valid one since a few have done it and the check engine error cleared up. This is not an expensive job and I hope that it's that and not anything to do with a wire harness. So try the least expensive stuff first and see what happens.

Thanks, Pablo! I was already thinking about the battery. Do I just take it to Autozone, indy shop or I should take it to the dealer? They charge me for everything so I'd want to stay away as long as I can.

Do they charge for the software update? If yes, how much? I found that some people got charged and some didn't. How do I avoid it, is there a bulletin or something?

So the light is not on today. It's a good thing, right???? But why did go away and why did it come on in the first place?

Mulchman, what kind of gas treatment do you recommend?

Originally Posted by Cectra

Thanks, Pablo! I was already thinking about the battery. Do I just take it to Autozone, indy shop or I should take it to the dealer? They charge me for everything so I'd want to stay away as long as I can.

Do they charge for the software update? If yes, how much? I found that some people got charged and some didn't. How do I avoid it, is there a bulletin or something?

So the light is not on today. It's a good thing, right???? But why did go away and why did it come on in the first place?

Mulchman, what kind of gas treatment do you recommend?

They are mostly the same. I use Lucas typicaly.

A good "indy BMW" guy would be the place for a battery and update if he has the software. You may have to go to the dealer for that. Do not go to AutoZone for the battery, because it has to be programed to the car. They will just throw it in. I also agree that the thermostat should not be too expensive, especially at an indy.

Thank you so much guys! I have an appointment for next Tuesday with the local indy shop.
One more question:
If the light went off, does it mean the thermostat is fine? My service adviser told me the light may go off and on if there's no actual problem but the harness is indeed creating "increased contact resistance."

Cars with the 6 cylinder N52 engine are prone to having the fault code 2EF5 which seems very similar to the 2EF4 info you got. I talked to a BMW Service Manager & he told me that the N52 error relates to the Map Thermostat too & that it (the thermostat) allows a change in direction of the flow of cooling towards to cylinder head which in turn helps aid a reduction in emissions. This code means this function is no longer working. He said that it does no harm to drive with 2EF5 & he also told me that they have seen loads of them in the workshop with this code & they don't do anything with them. He says that 9 times out of 10 it is a thermostat fault & a replacement will fix it, the other 1 out of 10 is down to a wiring fault.

He told me this off the record.

I hope this helps.

01 wiring harness, engine trans. module 1 12537525528 $52.64

http://www.realoem.com/bmw/partgrp.d...67&hg=12&fg=28

See if this link works. 3 of the 4 wire harnesses for your cars engine cost less than $70. The other is $700 of course. I wonder which one you need?

If your engine is surging at cold startup, I would believe that you have a faulty thermostat. Codes will show up in the BMW software, that will not show up on the generic OBD2 readers. The thermostat is a round 75.00, & can be installed in around 30 to 45 minutes. Believe it or not, low coolant % can throw a thermostat code. I found this while troubleshooting my thermostat using DIS. If you change the thermostat, flush the coolant while you have the system open. Get 2 gallons of BMW coolant to refill the system. The price can be between 17 to 25.00 a gallon, depending on your dealers pricing.

You can now buy a battery anywhere, at most automotive parts store. Some might install it for free, but it must be registered to the car by someone with BMW software. You can buy a new battery from 135.00 to 200.00 depending where you buy it. Make sure it is the correct battery for your car. The good thing about aftermarket batteries is that you get a 6 year warranty on most. BMW will only give you a 2 year warranty.

The IDrive is very slow on a 645 do to it's technology at the time. You learn to live with it. Your SAT radio will have poor reception for the same reason. BMW replaced my whole radio system for this same reason, & it still works poorly! Find a good mechanic that you can trust, that works on BMW's. If not, the dealer is your only choice.

Good Luck!

I had my software updated recently at the BMW dealer here in Houston. The cost if I remember right was around 189.00 I think. I'm pretty sure if you put the new battery in and hen had them up the software you could probably convice the guy to register and code the battery for you at the same time. Sure can't hurt to ask.

Good luck,

Originally Posted by rebel.ranter

He says that 9 times out of 10 it is a thermostat fault & a replacement will fix it, the other 1 out of 10 is down to a wiring fault.

Should I have it replaced now that the light went off anyway, as a preventative measure?

Originally Posted by Mulchman

3 of the 4 wire harnesses for your cars engine cost less than $70. The other is $700 of course. I wonder which one you need?

From what they told me, it'd be the $700 one. But labor is the main problem.

Originally Posted by HerbP

If your engine is surging at cold startup, I would believe that you have a faulty thermostat.

You can buy a new battery from 135.00 to 200.00 depending where you buy it. Make sure it is the correct battery for your car. The good thing about aftermarket batteries is that you get a 6 year warranty on most. BMW will only give you a 2 year warranty.

The IDrive is very slow on a 645 do to it's technology at the time. You learn to live with it. Your SAT radio will have poor reception for the same reason.

Good Luck!

Yep, surging is what the car is doing. Thank you for "translating" my sound effects. LOL Thermostat is not an expensive repair so I should do it anyway I guess and see what happens. So the engine light is off for now. Still replace it?

I'll have the indy shop test the battery. I'm sure they have this kind of software because all they work on is BMWs. Bavarian Auto. Good to know about the aftermarket warranty!

Originally Posted by houbmw-cm

I had my software updated recently at the BMW dealer here in Houston. The cost if I remember right was around 189.00 I think. I'm pretty sure if you put the new battery in and hen had them up the software you could probably convice the guy to register and code the battery for you at the same time. Sure can't hurt to ask.

Good luck,

$189 is not too bad, I guess. Did it work for you? Do you see a noticeable difference? I'm almost used to the slow stuff now

What is a good place to buy a battery from? I'll call the dealer and the indy shop to see how much the update would be.

Thank you!!!

Originally Posted by Cectra

Should I have it replaced now that the light went off anyway, as a preventative measure?

There's no need to replace electric thermostat as a preventative measure like the older more traditional mechanical thermostats. Do replace it if it is faulty now though, I was told that replacing the thermostat was the first step in trying to remove the error 2EF5, but it could also be a wiring fault.

Originally Posted by rebel.ranter

There's no need to replace electric thermostat as a preventative measure like the older more traditional mechanical thermostats. Do replace it if it is faulty now though, I was told that replacing the thermostat was the first step in trying to remove the error 2EF5, but it could also be a wiring fault.

Agreed. Personally if the code is no longer present then I would not spend the necessary dollars to do the replacement. If it pops up again, then replace. Electronics are funny at times. It may have picked up something that caused the error but it may have corrected itself.

Hey Elle,

Looks like doing the thermostat is an easy decision based on all the input. I would personally get the BMW indy to do that and install/register the battery. If they can do the updates as well, great. Ask how much it is of course, but my guess is that it will be close to the price of a parts store (for the same battery). If the price is close, give them the business. You want them to be there next time you have a problem. Plus you'll have one stop service and loose your car for the least amount of time. All while endearing yourself to your new mechanic. (IMHO)

Good luck,
Chris

Originally Posted by Mulchman

Hey Elle,

Looks like doing the thermostat is an easy decision based on all the input. I would personally get the BMW indy to do that and install/register the battery. If they can do the updates as well, great. Ask how much it is of course, but my guess is that it will be close to the price of a parts store (for the same battery). If the price is close, give them the business. You want them to be there next time you have a problem. Plus you'll have one stop service and loose your car for the least amount of time. All while endearing yourself to your new mechanic. (IMHO)

Good luck,
Chris

Thanks, Chris! My thinking exactly, especially the endearing part

Elle

Ok... I'm still going to take it to the shop on Tuesday and have them run the codes again. Since there was some code about the fluid, maybe I just need that.... Anyway, if anything comes out of it, I'll post an update.

Thank you very much!

Not sure when you last cleared the codes. But, when you do it takes a good bit of driving before all the sensors reset. The last ones will not reset untill many miles of driving have been done. A sensor will not send codes untill it resets. Any reader (or Autozone) can tell you if the sensors are set.

Originally Posted by Mulchman

Not sure when you last cleared the codes. But, when you do it takes a good bit of driving before all the sensors reset. The last ones will not reset untill many miles of driving have been done. A sensor will not send codes untill it resets. Any reader (or Autozone) can tell you if the sensors are set.

I don't know that the indy shop actually cleared the codes. The BMW SA said they may go off and on on their own. I went back to Bavarian and they said to wait until the light comes back. If it comes back. I'm in no hurry to spend money if noting needs fixing. I made an appointment to update the iDrive software in a couple of weeks.
So question about that. They said the cost is an hour labor. Their rate is apparently $105 an hour. Isn't it the same at the dealer? I read that indy shops charge about $50/h or so.

Thanks!

Specialists will charge more than a generic mechanic, but less than a dealer. $105/hr doesn't sound that bad, as long as he knows what he's doing with BMW's.

Just a quick update. Took the car in and Bavarian changed the thermostat. It took care of the light and everything seems to be running just fine. I'm waiting for the really cold weather to see if it comes back.

Thank you all for help and advice!