Hi Guys,

My wife just bought a 2012 Countryman S ALL4 3 weeks ago. Unfortunately, it seems to have not been a great choice for us, as we have major issues already, and with 50k miles we are out of warranty. Last week we were driving and got the 'reduced power' check engine light. Car would only go about 60, but we limped it home. I checked the codes and got Cylinder 2&4 misfire, as well as random misfire. I messed around with silly stuff for a while, including replacing MAP sensor and spark plugs, neither of which did anything.

Today I finally got into it, and after swapping coils, plugs, and injectors around, I finally just checked spark, and I am not getting a signal to coil #2 at all. I have 12V at the +wire, 0 ohm to ground, and 0 ohm to ECU connector, but no spark signal. Tried various coils and same thing. My oscilloscope is at work, but with the car running my DMM was showing AC voltage on the other coil wires, nothing on #2.

So a couple questions:
1) Is there any kind of software thing or something else that I don't know about that could cause this, or is it definitely a junk ECU?
2) If I buy a junkyard ECU, does it have to be exactly the same part number, or just from a 2012 CM S ALL4, or what?
3) If I do get a used ECU, do I have to pay the dealer a bunch of money to reprogram it or anything?
4) If yes to (3), can I get a copy of EDIS or something and do it myself?
5) Has anyone taken one of the ECU's apart? If so, how? I took out all the screws but can't get the cover off...

Any other words of wisdom would be much appreciated as well!

Thanks,
Pat

 

Without having a wiring diagram, you would have to check a couple of things.

Does the Countryman have a ignition control module? If it does you will need to check the output from the coil module. Also check the wiring from the coil module to the coil for resistance. I can't imagine that it would get a direct signal from the ECM, but again, without the wiring schematic I wouldn't know off hand.

To check the ignition control module's output I would recommend a Power Probe or Logic probe, not a test light. It should flash on each of the outputs the dead output will be #2 if its bad.

If there is no ignition control module, then you will have outputs from the ECU. The same applies, however be very careful as to not back probe the ECU (don't apply 12V to it).

Edit: Looking around I don't see an ignition control module, however I wouldn't rule it out. Really to properly diagnose this I would need to see a wiring schematic for it. And I don't have one for a Countryman. If you do, look up the page and scan it so I can see it. I can tell you where to go from there.

 

^ I don't have a wiring diagram either. However, I have never heard of a coil-on-plug system that had an ignition module separate from the ECU. Also, as I mentioned, I was able to find the coil#2 wire in the ECU plug and ring it out, so I know there is no wiring issue, and I assume if there was a module in between I would have seen some resistance as well.

I stopped by work and picked up my scope, I will verify that there is no signal coming from the ECU in the morning.

Edit: BTW, thanks for the quick reply!

 

Ok, I saw you have a +12V signal. But no "signal". An ignition coil is going to have a Positive 12V going to the Ignition Coil, but the signal is going to be a Negative one. This is one reason I said use a power probe. You could use a DMM, but you will have to put the positive lead to the battery plus and the negative lead to the coil output. Next you will have to turn the car over while your checking it. It will blink in rapid succession, this is the output signal. The other three should have that.

I don't see how you could have found the #2 coil output w/o a wiring schematic, unless by sheer luck. I'd suppose that if you have found #2, then you also know where 1,3, and 4 are. But you know which is the positive and which are the negative? Some hairy stuff you got going on there without a wiring schematic.

As for having a separate ignition module apart from the ECU, yes it is possible. There are many different set ups, but not seeing yours or knowing the Countryman, its hard to say. You say you have coil on plug system? So does from each plug do you have a wire about 1/4" from all four plugs to a central coil? Do two wires from cylinders go to one coil and two wires to another coil? Or does each plug have a coil pack on top of the plug? I doubt there is a distributor, but again, I need to see it to help.

Edit: Looking at a parts list, I see that the coil is a coil pack, so yes, the coil is on the spark-plug, so you would have wires running to each coil pack (likely from the ECU). If you ohm'd out the wires from the ECU to the Coil pack, you should have resistance maybe about 1 ohm. It should not be 0 or Open otherwise you done have the circuit. Ohm both the Positive side and the negative side. If you have an open circuit you need to repair it. If all circuits have resistance, then again check the output from the ECU for a ground "signal". It is a off-on signal while turning over the ignition. If you don't have that, then yeah.... you probably need an ECU and yeah, you will probably need to take it to the dealer. Most of the time, an ECU is not plug and play, there are a lot of things that need to be programmed.

Edit: On a side note, https://www.northamericanmotoring.co...r-message.html , it seems there are many people with the same problem. There is no real resolution in that thread other than maybe a bad coil pack.

 

Check the Oil Pressure Solenoid harness underneath - this is an issue on all N18 engines. The oil wicks up through the harness into the DME if it's not caught soon enough.

Example: https://www.northamericanmotoring.co...heck-it-4.html

 

OK, definitely bad ECU. I checked and confirmed no #2 spark signal with my scope this morning.

Took me a couple of hours of wrestling and fighting, but I finally got the ECU case apart, it was RTV'd around the outside and then thermal glued on the inside.

One of the coil drivers is obviously burned up. Part# NGD8201AG. Digikey has them for $1.62 each. I also damaged a capacitor while I was doing my "bear trying to get the honey" act on the case, so I need to figure out what value it is and order some parts.

Not counting my chickens quite yet, but looks like a doable fix, at a cost of around $10 once I pay for shipping and everything. I will post back when I am finished.

 

By chance did you ever clear the codes?

There is not separate driver for the coils, its a basic three wire set up. Power, ground, and a transistor inside the DME that controls the coil. which would be a signal.
Do you have a screen shot of what the pattern looked like when you scoped it? That pattern can tell you A lot about that cylinder.

 

Did you heat up the case at all when you separated it?

If it took you a couple hours of 'wrestling and fighting,' I'm worried you might've damaged the board when you separated the case halves.

It may not be immediately apparent, but it may fail further down the road.

 

Spoolin: Yes, I cleared the codes various times throughout the process. Cylinder 2 had no signal coming to the coil at all. Cylinder 1 had a nice square charge and then discharge just like you would expect. If you google the P/N I posted above, you will see that it is a high current ignition driver (inside the DME). As I mentioned, one of them had a big burnt spot on it and was obviously the problem.

Zillon: Yes, once I figured out that it was all glued together I heated it up with a heat gun to maybe 160F or so just to soften it. As far as the wrestling, I may have been a little colorful with my language. The main reason it took so long is I was being super careful not to damage anything. Still it was a huge pain because there is an RTV bead all around the edge which was very hard to reach, as well as a thermal glue in between parts of the board and both cases. I did not ever flex the board much or anything, so I am reasonably confident I didn't damage anything other than the one capacitor. That said at this point I have nothing to lose, so we will see what happens!

EDIT: I'll try to post a pic of the burnt ignition driver tomorrow.

 

Good to hear you took some precautions when separating the case. Eager to hear the outcome of this.

 

As promised, here is a (bad) picture of the DME board with burnt ignition driver (arrow).

I am ordering parts today, hopefully will have it fixed by the end of the week. I am going to go ahead and order 5 of the IGBTs just in case this happens again.

 

OK, after a 1 day delay due to UPS being late with my digikey package, I got my friend at work (who has steadier hands than me) to solder the new driver in for me. Put some thermal paste and some RTV on the covers and put the ECU back in the car. Runs perfect again! I am not 100% confident yet until I put a couple tanks of fuel through it, but it looks OK at the moment.

 

Awesome. Glad to hear it could be repaired.

 

Before you re-assemble, check carefully over all of the soldered connections. The solder used from the factory is some low-temp stuff that is susceptible to failing when getting medieval on the case with the heat gun.

 

Watch those ign. coils carefully, an intermittent issue with your #2 coil may have burned the board in the ECU. BMW in the past lost most Motronic ECU's to ignition issues versus fuel injector drivers.
Congrats on fixing your car though. serious respect for diving carefully in there and repairing it.

 

Update: About 2 weeks later, the driver for cylinder 3 burned up too. This time the coil failed also. I didn't label the coils the first time, but I think probably the #2 coil got moved to 3 and caused both failures. Good call Pure Red.

Luckily I bought a couple extra coil drivers, so I replaced #3 as well, and am back on the road. I am replacing all of the other coils and plugs as well as soon as UPS brings me the parts. Hopefully that will be the end of it, as we are having to avoid taking trips due to lack of confidence in the car.

 

Sigh. The saga continues..... Oh well, sounds like you're totally on top of it.

 

Ok, another update:

I replaced all the coils.

I tried replacing the plugs with Denso Iridiums, which are the only US-available plugs I could find which are spec'd for the car, but the car ran like crap unless I gapped them down to .030 or so. I couldn't find any reference for the appropriate gap spec, but the OEM Berus measured .040", so I am assuming it is 1mm. Funny thing: with these plugs the car would hesitate all over the place, but would never throw a misfire code (or any other code). I sent the plugs back to Amazon. I'm not paying $20+ for Berus, so these will have to do for now. I did note that although the plugs were externally identical, resistance from top to center electrode was about 3.2k ohms for the BERU, 4.1k ohms for the Denso. Maybe that explains the lack of spark energy.

So I put the original Beru plugs back in. Seems to be fine, she has been driving it for a couple weeks now with no issues. Getting 29MPG, so it can't be running too bad.

I'm hoping that fairly soon there will be a NGK plug available for this car and I can change them, but until then (knock on wood), it seems that replacing the coils has prevented any further ECU failures.

 

Enjoyed reading this and following your mad fixit skills. Reminds me of the guy who showed up years ago to fix my first big screen tv with a soldering iron in hand, no other tools and fixed it in 5 minutes.

 

had same problem. changed all 4 coils and plugs. had no signal of pulsing ground on #2 coil.
coils #1, #3 and #4 have pulsing ground. getting DTC misfire for cylinders #2 & #4.
looks like ECM.... Gonna try one and have Dealer program it.....

 

I have a similar scenario with a 2010 Non-S that has a persistent misfire on cylinder 2 but only when engine is warmed up. This misfire does not occur when the engine is cold.

-Swapped coils
-Swapped injectors
-Swapped plugs
-Compression is even across all cylinders

but the misfire remains persistent on number 2.

When the car misfires, if I turn it off and come back later it will not misfire until its warmed up.

When the car begins misfiring, when I unplug cyl 2 nothing happens, I put a sparkplug on the coil while still connected to the harness and the spark plug did not spark, (I know that's crude ;-)) so it seems there's no signal getting to the the coil.

A year ago this happened and the problem mysteriously disappeared on its own and its now back. So started suspecting my DME is bad, I had it cloned and the new DME works and does the same thing. I fried my CAS module last year after a series of jumpstarts when the car had a bad battery and I got the CAS cloned and it solved my issues, so I was hopeful.

So now I'm at the crossroads - What are the odds I got a dud DME with the same exact issue on the same cylinder? Hard to swallow. Or could I have a bad harness? Any ideas? I'm getting exhausted with this car.