B9 - Function, Leak Detection pump code

[DeafM5]

I am little stumped with this code. The code popped up (SES) first time in 3 years. I looked into the code and decided it was a defective pump, so I replaced it last week. I also cleared the code. The code came back.

Is there a way to find out the actual issue?

I am going to fire up my laptop with INPA to read more detailed codes as my first go to tool is Autel scanner.

[asianvenom]

That time i was chasing leak detection code was a leaky fuelpump gasket not sealed properly in my 330. So another word you have a leaky fuel system somewhere, worth checking your gas cap.

Sent from my SM-G965U using Tapatalk

[CPHES]

+ 1 - time for a smoke test to see where you are leaking

[DeafM5]

I have not touched any fuel system during my ownership beside fuel rail being removed for engine work. Only thing that see more use is fuel cap being removed for fueling and replaced when done often. I could grab a fuel cap to try to see if this problem goes away.

[Frankie]

Isn't this fun?...chasing down ridiculous, asinine faults just to keep our cars on the road.

Yes, you probably need a new gas cap. Try that first. If that doesn't do it, you'll need a smoke test to determine the source of your leak.

BTW: this fault appears on Peake readers as "Evap system large leak" or "Safety concept monitoring". Enjoy.

[clarkitect]

Check this thread.
https://www.bimmerforums.com/forum/s...Check-this-out

[DeafM5]

Isn't this fun?...chasing down ridiculous, asinine faults just to keep our cars on the road.

Yes, you probably need a new gas cap. Try that first. If that doesn't do it, you'll need a smoke test to determine the source of your leak.

BTW: this fault appears on Peake readers as "Evap system large leak" or "Safety concept monitoring". Enjoy.

I will try, but I know for sure that gas cap does not cause this code. I'll order a new one.

Check this thread.
https://www.bimmerforums.com/forum/s...Check-this-out

That is my next step. Replace the wirings and shrink wrap it. Lastly, re route the wiring to avoid this situation again.

[kouks]

After the gas cap test, here's my suggestions (I actually did this on my son's e39 about 9 months ago, code is gone)

1. Look under the car. Locate the fuel tank (both left and right sides) and the fuel lines going forward. Are there any wet spots? If so, bingo! Fix the leak.
2. A bad fuel filter can cause fuel pressure issues and cause the code too.
3. Trace any fuel smells in the engine, find the leak if so, and fix it.
4. Remove the back seat, remove the cap over the fuel pump and look for wet spots or fuel smells, use your fingers to try and find any leaks and fix them. The fuel lines run forward and down the front of the fuel tank. Hopefully none of those are cracked since the whole tank has to come out.
5. If none of this helps, then you need to smoke test the evap system from vacuum hoses up front. Find out where the smoke is venting and fix it. The fuel tank vent system is in the rear wheel well of the e39, I think its the same for the e38.

Mine was a fuel leak from a small crack in the tank. I did all the tests since I thought the tiny fuel leak was not the issue, but I was proven wrong.

[pyite69]

FWIW I had this problem and on my 99 540i and it was an easy fix.

There is a hose that goes from the left CCV port on the back of the engine, through the cabin air filter housing, and down into the wheel well.

Apparently it is a vacuum line for some sort of fuel evaporation function. I think later models have a cap on the left CCV port and no hose. Mine had a both hanging disconnected hose and a cap on the CCV! I plugged the hose in and the code is gone. Presumably this was from some repairs by the previous owner.