[BMW Guy]

3166 - Fuel tank ventilation system: Malfunction.
387F - Power management: Standby current violation.

I've been experiencing these codes ever since I tuned my car with MHD. The 387F code might be the cause of why my CA never worked. The 3166 code I'm not sure of. I can erase both codes and then they show up again, the 3166 more than the other one. Any idea? The car is a 335i 2011 with 102k on it. Mods are downpipe, charge pipe, boost pipe, and intercooler. Running stage 2+.
Thanks for any help!

[lookalikehuuh]

Ok so let's take it 1 by 1 for each of the codes.

3166- This usually means there is some type of leak in the EVAP system for your car... It can be as simple as a bad gas cap or a loose/leaking evap hose. Usually you can smoke test the system to figure out where the issue is coming from.

387F- This means something is not turning off when the car is "off" or "sleeping" There is higher power draw than what the car expects to have in that mode so it sets this code. It is common when people install aftermarket stereo equipment or other aftermarket equipment that this code is set. Also sometimes is a failing module that doesn't go to sleep properly anymore. This one is a bit tougher to diagnose, something like an "amp hound" could be useful in diagnosing this because you can figure out which circuit is drawing excessive current based on the reading at the fuse.

The 387F won't be the reason your CA never worked, but the fact your CA never worked could trigger the 387F if the module that controls CA isn't going to sleep or waking properly (which it probably isn't)

[BMW Guy]

Originally Posted by lookalikehuuh

Ok so let's take it 1 by 1 for each of the codes.

3166- This usually means there is some type of leak in the EVAP system for your car... It can be as simple as a bad gas cap or a loose/leaking evap hose. Usually you can smoke test the system to figure out where the issue is coming from.

387F- This means something is not turning off when the car is "off" or "sleeping" There is higher power draw than what the car expects to have in that mode so it sets this code. It is common when people install aftermarket stereo equipment or other aftermarket equipment that this code is set. Also sometimes is a failing module that doesn't go to sleep properly anymore. This one is a bit tougher to diagnose, something like an "amp hound" could be useful in diagnosing this because you can figure out which circuit is drawing excessive current based on the reading at the fuse.

The 387F won't be the reason your CA never worked, but the fact your CA never worked could trigger the 387F if the module that controls CA isn't going to sleep or waking properly (which it probably isn't)

Thanks. I think the 387F code is from my dashcam being plugged in so maybe it's still drawing some power from the cigarette lighter. The car is getting a Diag on Wednesday so I'll see what they find about the other code.

[spazzz]

I have the same 2 codes in a X1, E84 35i
The 387F has been there since I bought it and hasn't been a problem. I do throw a CTEK on it every few weeks.
My CA never worked either. I unplugged the handles, removed the module and VO coded comfort access out...still there.

That dang 3166 popped up after I bought it and had some immediate jobs done at my indy. Valve cover, OFHG and Oil pan gasket.
He said he took it off the lift and it wouldn't start so he put in a new starter.

I drove home and next day it will not start.
That is when the 3166 and A0C1, output terminal 50 showed up.
I had it towed to the indy and he replaced the engine bay B+ cable and all the grounds.

It has been running great except the 3166 never left. I replaced the gas cap, tank vent valve in engine bay, (DMTL pump, Canister...bought from ebay) and air vent.
I smoke tested and no leaks. Vent valve triggers with Protools and I ran the DMTL test in INPA and it said system sealed.


I eventually tuned the POS with MHD hoping it would somehow fix the 3166, it didn't.
The electric tape covering the dash light helps.

Get back after your appointment Wednesday. BMW Guy, I sure would appreciate it.
I have have read every 3166 post there is...more than once.

[lookalikehuuh]

Originally Posted by BMW Guy

Thanks. I think the 387F code is from my dashcam being plugged in so maybe it's still drawing some power from the cigarette lighter. The car is getting a Diag on Wednesday so I'll see what they find about the other code.

I doubt this is the cause of the code unless your cig lighter is still on after you turn off the ignition. This code is for drain after the car ignition is off and the car is "sleeping" If you had a hardwired camera that pull current directly fro the battery I could see that causing it.

[darkfires102]

OP, You use MHD. If you keep the adapter plugged into OBD2 while the car is asleep, it'll trigger the code. OBD2 is always powered. Nothing to worry about.

[BMW Guy]

Originally Posted by spazzz

I have the same 2 codes in a X1, E84 35i
The 387F has been there since I bought it and hasn't been a problem. I do throw a CTEK on it every few weeks.
My CA never worked either. I unplugged the handles, removed the module and VO coded comfort access out...still there.

That dang 3166 popped up after I bought it and had some immediate jobs done at my indy. Valve cover, OFHG and Oil pan gasket.
He said he took it off the lift and it wouldn't start so he put in a new starter.

I drove home and next day it will not start.
That is when the 3166 and A0C1, output terminal 50 showed up.
I had it towed to the indy and he replaced the engine bay B+ cable and all the grounds.

It has been running great except the 3166 never left. I replaced the gas cap, tank vent valve in engine bay, (DMTL pump, Canister...bought from ebay) and air vent.
I smoke tested and no leaks. Vent valve triggers with Protools and I ran the DMTL test in INPA and it said system sealed.


I eventually tuned the POS with MHD hoping it would somehow fix the 3166, it didn't.
The electric tape covering the dash light helps.

Get back after your appointment Wednesday. BMW Guy, I sure would appreciate it.
I have have read every 3166 post there is...more than once.

Back from my appointment. Issue number one: My car was pulling to the side under moderate to hard braking. They inspected and said that they couldn't replicate the issue and that all of my brakes, tires, and suspension were fine. Strange...... Next, because I cleared the 3166 code, they couldn't Diag that I guess. Finally, my CA was not working because the key I was using was key number 3, and only two keys can be programmed to CA. $251 later, CA is working. They said my brake fluid was discolored and recommended flushing it. However according to Carfax, the previous owner flushed it in January of this year. Should I still change it? I'll do it myself if it needs to be done, but 2 years seems to be the interval everyone follows.

[spazzz]

It is not going to hurt flushing the brake fluid again.
I would do it to make sure all the air is bleed out of the lines and then you will have a solid starting point.
Good to hear the comfort access worked out for you.
I was curious if maybe they thought programming the DME would solve the 3166.
You might have to get the tape out for the cluster

[BMW Guy]

Originally Posted by spazzz

It is not going to hurt flushing the brake fluid again.
I would do it to make sure all the air is bleed out of the lines and then you will have a solid starting point.
Good to hear the comfort access worked out for you.
I was curious if maybe they thought programming the DME would solve the 3166.
You might have to get the tape out for the cluster

What do you mean by programming the DME? I'll probably flush the system in the next few months since it will be the only fluid on my car that I haven't changed this year, though I hope they weren't just trying to get money out of me since that was the only thing they could find wrong besides the key not being programed. My CEL isn't always there so I'll leave the tape aside for now. Maybe I'll try replacing my gas cap at some point. Still strange it wasn't there tell I flashed stage 2............