[SOLVED??] Recurring limp mode 5-8 misfires, replaced TA, still getting limp mode..??

[EJT86]

Not sure if that's low voltage for a battery. But last time I tested mine after sitting 12days in winter, getting low battery warning and running it letting it recharge mine was at about 15v

[vsix]

Originally Posted by nick3753

I've never heard of a battery causing limp modes, but if it's six years old at least replacing it won't be potentially wasted time and money. Maybe you will get lucky and it will fix the issue.

It happened to me, I had an so called christmas tree, reduced power all kind of CEL's.
All came from an bad battery.
It looked like my TBA's went bad but no it was just the battery.
Trust me been there...

[Rat3d ///M]

Quick update on my situation..

Today I pulled the new throttle actuator and put my old one back in. While I was in there, I swapped all of the ignition coils from side to side (1-4 to 5-8 and vise versa). Went for a drive, and while cruising down the autobahn at around 55 mph I hit limp mode. So I pulled over, and scanned the codes with the car running and the limp mode activated this time (something I hadn't done before). I got cyl 5-8 misfires (as usual, meaning the problem is not the ignition coils) and I got something new as well...

P0223 popped up for Throttle/Petal Position Sensor/Switch 'B' Circuit High Input. I turned the car off, restarted it and limp mode was gone (as usual), rescanned the car while it was running (without limp mode) and I got my cyl 5-8, but the P0223 was gone..interesting.

Internet says possible cause for the P0223 is a faulty TPS, but when I am in limp mode my idle raises to around 1000 RPMs (and the car shudders and shakes) so I wonder if the P0223 was simply caused by my temporary high idle (maybe the car was confused by the high idle so it through the code?) Or is it likely that my TPS is my cause for this? I did get a TPS sensor code once before (though it was for bank 1, and I also had an IAT sensor and Coolant Temperature sensor code as well).

My next step is to switch my o2 sensors just to rule that out, but I am very interested in the possibility of my TPS sensor being the cause of this. Can a faulty TPS sensor cause cyl misfires on one bank? A few issues I have had in the past before all this came about was the car had trouble starting a couple times (engine would crank continuously but wouldn't fire, until I turned the ignition off and tried again). This happened twice, and I have also noticed a bouncing idle a couple times. I kind of wrote these off as flukes, or issues that I wouldn't worry about until they became more severe, but I wonder if maybe this is all pointing toward a faulty TPS?

[BPMSport]

Maybe the new throttle actuator is bad as well? Try swapping the bank one actuator with bank 2 and see if it moves to the other bank. That new fault you got can be caused by a faulty actuator.

Switch the o2s first.

[Rat3d ///M]

Originally Posted by Mike Benvo

Maybe the new throttle actuator is bad as well? Try swapping the bank one actuator with bank 2 and see if it moves to the other bank. That new fault you got can be caused by a faulty actuator.

Switch the o2s first.

I guess it's possible that I got a faulty actuator, though I hope thats not the case because I just sold the new actuator and I doubt BMW would give me my money back on it. Either way, I will keep the possibility of switching the actuators in mind just to rule them out (not looking forward to going in there for a third time).

Today I hit limp mode twice and when I scanned the codes I had cyl 1, 2, 3, 5, 6, 7 and 8 misfires (all but cyl 4). I am very confused at this point

[BPMSport]

Originally Posted by ||||||||||

I guess it's possible that I got a faulty actuator, though I hope thats not the case because I just sold the new actuator and I doubt BMW would give me my money back on it. Either way, I will keep the possibility of switching the actuators in mind just to rule them out (not looking forward to going in there for a third time).

Today I hit limp mode twice and when I scanned the codes I had cyl 1, 2, 3, 5, 6, 7 and 8 misfires (all but cyl 4). I am very confused at this point

Try replacing the fuel tank vent valve.

[mechanicdavid24]

Pay for diagnostic at dealership instead of throwing parts, at least that way they are liable for the diagnostic

[Apex Everything]

Originally Posted by mechanicdavid24

Pay for diagnostic at dealership instead of throwing parts, at least that way they are liable for the diagnostic

My issue matches his and if his code pulling with this issue is like mine it will tell you some of the cylinders misfiring one time, then the next all, then next time some, etc.

[Rat3d ///M]

So here is what I have done so far:

1. Switched out Bank 2 throttle actuator
2. Swapped Coils from side to side
3. Swapped primary o2 sensors from side to side

None of these have fixed my issue. Still misfires on cyl 5-8 consistently. So my options are:

1. Take car to dealer and have them sort it out
2. Keep troubleshooting (don't know where to go from here)
3. Start replacing parts until I find the issue

1 and 3 could be expensive, so if there are other options for #2, I would like to try them. Any ideas? If I do go straight to #3, what would be a good part to start with? I occasionally get a bouncing idle when I first start the car and the car has failed to start a couple times (turns over strong but won't fire first time) so I am leaning toward a bad ICV. I want to start with the most likely culprits first, not the cheapest.

[IIAp3x]

I would start with the battery... I thought a read it was six years old in your thread, but I may have missed something... A battery on its way out can cause all kinds of codes if it is unable to keep up... Every sensor in our cars are voltage driven for plausible signals... Insufficient battery capacity can cause many of these sensors to function improperly throwing random codes...

12.2 at idle is not normal... You should be 13.9 or higher...

I your battery is 6 years old its time for a new one anyways... i would start there, and it may save you a lot of time and money wasted in chasing ghosts...

[Apex Everything]

Mine with the same codes ended up being a broken valve spring.

[Rat3d ///M]

Originally Posted by Apex Everything

Mine with the same codes ended up being a broken valve spring.

I doubt my issue is mechanical. Yours wouldn't go out of limp mode, but mine runs perfectly fine until it goes into limp mode (totally random, but seems to only be at low speeds) and turning the car off resets everything like there is nothing wrong. I don't think that turning the car off then on again would clear any type of internal damage to the pistons, valves, camshaft or crankshaft. It's definitely an electrical failure of some sort, likely either a sensor or some type of actuator. I just don't have a clue which one and I'm hesitant to start throwing money into it until I find the issue (what can I say, I'm frugal and was really hoping I could get a better idea of where to start before I replace a battery just to "rule it out"). If I wasn't so afraid to just start buying parts and replacing shit I would've had it fixed weeks ago and likely $1000 later.

Can someone school me on batteries, specifically what kind I will need? I may start there just because everyone seems to be convinced it's a definite possibility that is my issue.

I certainly appreciate all the advice, but I'm very surprised no one has been able to tell me "that sounds like _______, try to do ________ and see if it fixes the issue". Being that it is always one whole bank that is misfiring, there has to be a part that has an identical part for the other bank that I could swap to see if the error follows (like I did with the coils or the o2 sensors). It seems like everyone is just as lost as I am and just guessing at what it could be. I've heard everything from o2 sensors to ignition coils and spark plugs to throttle actuator to ICV valve to battery to the fuel tank breather valve. While it's possible one or more of these may be the culprit (or faulty in some way) that's a lot of randomness to start throwing money at hoping it fixes the problem.

There has to be only a few certain items that would cause a misfire on an entire bank? O2 sensors and coils are bank specific, as are throttle actuators, but I've ruled all those out. What else is bank specific? Throttle Position Sensor I would imagine? I've read that the Ion Current Control Unit could also cause my issue (but I'm not sure the S65 has it, may only be an M5 thing). I haven't ruled out injectors or something to do with fuel yet. Is there anything I could try to rule injectors/fuel rail out? Or any sensors affiliated with them that could be faulty?

[Apex Everything]

Originally Posted by ||||||||||

I doubt my issue is mechanical. Yours wouldn't go out of limp mode, but mine runs perfectly fine until it goes into limp mode (totally random, but seems to only be at low speeds) and turning the car off resets everything like there is nothing wrong. I don't think that turning the car off then on again would clear any type of internal damage to the pistons, valves, camshaft or crankshaft. It's definitely an electrical failure of some sort, likely either a sensor or some type of actuator. I just don't have a clue which one and I'm hesitant to start throwing money into it until I find the issue (what can I say, I'm frugal and was really hoping I could get a better idea of where to start before I replace a battery just to "rule it out"). If I wasn't so afraid to just start buying parts and replacing shit I would've had it fixed weeks ago and likely $1000 later.

Can someone school me on batteries, specifically what kind I will need? I may start there just because everyone seems to be convinced it's a definite possibility that is my issue.

I certainly appreciate all the advice, but I'm very surprised no one has been able to tell me "that sounds like _______, try to do ________ and see if it fixes the issue". Being that it is always one whole bank that is misfiring, there has to be a part that has an identical part for the other bank that I could swap to see if the error follows (like I did with the coils or the o2 sensors). It seems like everyone is just as lost as I am and just guessing at what it could be. I've heard everything from o2 sensors to ignition coils and spark plugs to throttle actuator to ICV valve to battery to the fuel tank breather valve. While it's possible one or more of these may be the culprit (or faulty in some way) that's a lot of randomness to start throwing money at hoping it fixes the problem.

There has to be only a few certain items that would cause a misfire on an entire bank? O2 sensors and coils are bank specific, as are throttle actuators, but I've ruled all those out. What else is bank specific? Throttle Position Sensor I would imagine? I've read that the Ion Current Control Unit could also cause my issue (but I'm not sure the S65 has it, may only be an M5 thing). I haven't ruled out injectors or something to do with fuel yet. Is there anything I could try to rule injectors/fuel rail out? Or any sensors affiliated with them that could be faulty?

One thing you can learn from mine at least is, it was ONE cylinder that was causing the whole bank to go crazy.

Same might be for your issue, even if its not mechanical an issue in one section can be causing all to go crazy.

[vsix]

Same here!
One little electric inconsistency and everything is waving the red flag.
Had all sorts of error codes, Bank misfires, TBA's, ESP- ABS warning, limp mode, even an jumpy idle....caused by my old battery.
As for wich one exactly?
Can't tell you, didn't tracked it. What I know though, I got Volta with 90 amp iirc.

[Apex Everything]

Updates?

[4LNAMV8]

when my old battery was dying, there was one time i did not drive my car for 2 weeks. the first time i drove my car after that, the service engine soon light came on, and the idrive system showed the "increased emission" message on screen besides the low battery message. i pulled 2 error codes, which i wrote down somewhere but can't find now. I only remember they were both emission related. after another day of driving, the codes and the service engine soon light went away on their own as soon as the car stopped warning me about low battery. I haven't had a problem since. i think OP should give replacing your battery a try. Your battery is 6 years-old, changing the battery can only do your car good

[Rat3d ///M]

no updates yet. i have a k/dcan cable on the way and am downloading BMW Standard Tools package to help me diagnose my issue. if I can't find anything elwe out from that I am going to start replacing parts beginning with battery ICV and Secondary Air Pump

[Apex Everything]

Originally Posted by ||||||||||

no updates yet. i have a k/dcan cable on the way and am downloading BMW Standard Tools package to help me diagnose my issue. if I can't find anything elwe out from that I am going to start replacing parts beginning with battery ICV and Secondary Air Pump

But your going to be replacing parts that could not be broken, at this point I think taking it to the dealer and at least paying for diag is worth it.

[Rat3d ///M]

Quick little update, downloaded BMW Standard Tools and ran the codes in INPA. Here is what came up after a misfire the other day



So, the error codes provided translate to the below:

2B39 Combustion misfire with cut-out cyl 5
2B3A Combustion misfire with cut-out cyl 6
2B3B Combustion misfire with cut-out cyl 7
2B3C Combustion misfire with cut-out cyl 8
2B41 Combustion misfire with cut-out several cyl
2B57 Motor emergency programm activated
2796 Check bottom stop
2B44 Combustion misfire with emissions deterioration cyl 3
2B46 Combustion misfire with emissions deterioration cyl 5
2B47 Combustion misfire with emissions deterioration cyl 6
2B49 Combustion misfire with emissions deterioration cyl 8
2B4E Combustion misfire with emissions deterioration several cyl

So, pretty much the same as with Carly and a generic OBDII scanner. I was really hoping that INPA would tell me more. Bummer.

In other news, I haven't done shit in the way of figuring out what is causing this. But now that I have INPA are there diagnostics or tests I can do that will help me narrow it down? I'm not 100% confident in my INPA abilities to just start pushing buttons.

[Rat3d ///M]

Bump. Quick update in post 1. Hopefully ill get this figured out this week.

[Bavarian Beast]

Holy crap dude.

[Rat3d ///M]

Originally Posted by Bavarian Beast

Holy crap dude.

Holy crap indeed! This issue (and my DCT leak) are seriously interfering with my VT1-550 plans for this fall, but hopefully this will be my solution. Ill update the thread once this issue is solved. How's Hawaii btw? You regret bringing the ///M yet, or it's not as bad as you thought?