What the hell is going on with my m6. stalls, misfires, ecu's replaced. wtf .

[jporter396]

What the hell is going on with my m6. stalls, misfires, ecu's replaced. wtf .

Hello all, have had my m6 for a year now and still hasnt ran right and has been hell on wheels.
bought with blown engine/rod bearings shredded. rebuilt with rk autoworks.

after about 2k miles had ecu fault codes , engine stalling/turning off randomly and misfiring. engine seemed fine defintely seemed electrical.
bought new battery, replaced and recoded ecu's with used ones. car ran for 1k miles fine and misfiring came back again just now on and off.
also turbocharger aux pump code was present soon as ecu was replaced and cannot get to turn off even after changing pump. ecu was off a 2014 mine is a 2013 m6. perhaps they arent compatible years?

below are ista codes pulled from car fresh after misfiring sequence three times on the highway.







the shop that replaced the ecu's, pretty reputable shop. bimmer ecu solutions in san diego, just replaced the crankshaft position shelter and said flywheel cut the tip of the sensor off and if it gets shaved off again to replace flywheel or get that looked at. which seems extremely odd to say the least!


have appt this wednesday, any help for this weird issue will help so i can finally enjoy this damn car!

[HeyKC]

Did you have a stock rebuild or a forged? Stock tune?

[jporter396]

Originally Posted by HeyKC

Did you have a stock rebuild or a forged? Stock tune?

Stock rebuild. Stock tune

[jporter396]

car completely died today and christmas tree of lights lit up on the dash, same exact thing happened before replacing first set of ECU'S / DME'S.

seems like there is a progressive short in the ecu wiring that causes intermittent misifring that then leads to complete mess up once its driven to this final stage.

will pull ista codes on this most recent event tonight.

[M6Roar]

I would say check the Alternator voltage and check for any voltage drop during the misfire sessions. Also, since the engine swapped maybe trace your harness and check that nothing is left unplugged or short circuit

[SixteenM6]

Check for missing and/or blown fuses as well.

[Kamate]

Does your place have rodent problem? Those bastards chewed a couple of my x5 wires right by the fender and cause my car to go haywire when i goes over bump or hard turn. I found out the problem when I started to yanking/pulling on the main harness and it would cause the problem to appear. That help me narrow down the cause. Found a couple wires got chewed up and would open/short when i goes over bump and stuff.

[jporter396]

Thanks for the replies everybody.

Alternator being replaced right now. Voltages during multiple of these codes during engine time read 11.85v 11.9v 11.62v and a few were at 9.2v and 9.4v which is too low so either the alternator or voltage regulator are on the fritz or the dme\ecus are faulty again and requesting wild voltage numbers.


Will update when I am able to test and drive

[jporter396]

Originally Posted by Kamate

Does your place have rodent problem? Those bastards chewed a couple of my x5 wires right by the fender and cause my car to go haywire when i goes over bump or hard turn. I found out the problem when I started to yanking/pulling on the main harness and it would cause the problem to appear. That help me narrow down the cause. Found a couple wires got chewed up and would open/short when i goes over bump and stuff.

Thanks I'll be sure to check them when I can next. Engine was rebuilt a year ago so I'd imagine everything was fine when put back together and no rats here really

[jporter396]

Originally Posted by M6Roar

I would say check the Alternator voltage and check for any voltage drop during the misfire sessions. Also, since the engine swapped maybe trace your harness and check that nothing is left unplugged or short circuit

Replacing that today I sure hope that's the problem. Only reason I wouldn't think it was this is because of the progression of the misfires happening as I drove the car more and more after ecu replacement and car being fine for 1000 miles right after ecus replaced.

Will update when I can drive soon after alternator replacement

[rcrs2]

any update on this? I'm seeing similar errors

[jporter396]

Originally Posted by rcrs2

any update on this? I'm seeing similar errors

Alternator didn't fix problem. Issue came back and engine stalled while reversing. Got 250 miles in and thought it was fixed but NOPE ! Same ista codes come back up. What are you issues\symtoms\codes ?

Have a service appointment Thursday with bmw dealer to further diagnose.

[Alrock31]

Make sure all the plugs on the DME are locked in correctly. I went crazy with all the random codes only to find out 1 of the plug wasn’t locked in.