E46 what could be causing these codes?

[LLC24]

Got a 325ci with the following codes coming up:
-44 activation solenoid valve, tank ventilation.
-E4 fuel trim bank 2 permissible range exceeded
-E3 fuel trim bank 1 permissible range exceeded
- 08 air mass flow sensor

I’ve had the mass air flow done so don’t think that’s the issue. Anyone have any idea what I need replacing to fix this? Thanks in advance

[g3org3y]

What make of MAF did you get? I hear the cheapo eBay specials are often problematic.

Any possible vacuum leaks?

[d_a_n1979]

LLC24 said:

Got a 325ci with the following codes coming up:
-44 activation solenoid valve, tank ventilation.
-E4 fuel trim bank 2 permissible range exceeded
-E3 fuel trim bank 1 permissible range exceeded
- 08 air mass flow sensor

I’ve had the mass air flow done so don’t think that’s the issue. Anyone have any idea what I need replacing to fix this? Thanks in advance

As George has said.

The MAFs need to be BMW ONLY, or the make of them (can’t remember who it is). Aftermarket ones are ste at best... So swap out the MAF again if it’s an aftermarket one and see how the car is thereafter

But check the air intake boot from MAF to throttle body and if any splits, replace as it’s letting air in after the MAF

Also check the DISA and CCV systems. Plenty of How To’s re these on Google/YouTube

Edited by d_a_n1979 on Monday 31st August 10:07

[LLC24]

d_a_n1979 said:

LLC24 said:

Got a 325ci with the following codes coming up:
-44 activation solenoid valve, tank ventilation.
-E4 fuel trim bank 2 permissible range exceeded
-E3 fuel trim bank 1 permissible range exceeded
- 08 air mass flow sensor

I’ve had the mass air flow done so don’t think that’s the issue. Anyone have any idea what I need replacing to fix this? Thanks in advance

As George has said.

The MAFs need to be BMW ONLY, or the make of them (Camt remember who it is). Aftermarket ones are ste at best... So swap out the MAF again if it’s an aftermarket one and see how the car is thereafter

But check the air intake boot from MAF auto throttle body and if any splits, replace as it’s letting air in after the MAF

Also check the DISA and CCV systems. Plenty of How To’s re these on Google/YouTube

Okay cheers guys, I don’t think it was a BMW one to be honest so I’ll do that and hopefully it sorts it.

[g3org3y]

IIRC the OEM item is a Siemens VDO.

[LLC24]

g3org3y said:

IIRC the OEM item is a Siemens VDO.

Do you know the part number by any chance?

[g3org3y]

LLC24 said:

g3org3y said:

IIRC the OEM item is a Siemens VDO.

Do you know the part number by any chance?

Check the BMW part number for the 325 in RealOEM and then you can use autodoc.co.uk to cross reference part numbers for VDO, Hella etc.

[sibriers]

Tank ventilation error might be causing the rest... Check fuel pressure at the fuel rail - might be low.

Easy to throw a lot of money at these issues - you really need to fix any vacuum leaks found with a smoke test. A decent OBD scanner / app will show if the fuel trims are + or - (likely 15% positive - run out of adjustment).
- Careful if that's the case - the engine might be running lean if it thinks it needs more fuel and can't add it.

Fuel pump and filter would be my next point of call if not looked at within 80k.

If you're not up for DIY, take it to a BMW specialist (not dealer) - they'll have seen this many times before!

[LLC24]

sibriers said:

Tank ventilation error might be causing the rest... Check fuel pressure at the fuel rail - might be low.

Easy to throw a lot of money at these issues - you really need to fix any vacuum leaks found with a smoke test. A decent OBD scanner / app will show if the fuel trims are + or - (likely 15% positive - run out of adjustment).
- Careful if that's the case - the engine might be running lean if it thinks it needs more fuel and can't add it.

Fuel pump and filter would be my next point of call if not looked at within 80k.

If you're not up for DIY, take it to a BMW specialist (not dealer) - they'll have seen this many times before!

I had a smoke test done and all vacuum leaks repaired already and although it’s not oem from bmw I did replace the mass air flow sensor quite recently and the fuel filter has been done too. The fuel pump might be a good shout... I’m not sure what the “activation solenoid” means to be honest. The car is on 141k miles at the moment & spent a fair bit to get it running right so wouldn’t want to keep throwing money replacing things that don’t need to be done yet as you say. Thanks for the help

[RUSSELLM]

Are you still getting a MAF sensor fault ?

If so, that’s a 1st point sensor, so that will need rectifying first. The only MAF sensor faults I’ve seen, where another item may be at fault is ‘correlation’ DTC’s, where it’s comparing a reading from one sensor against readings from another sensor.

[Shanksy87]

Throwing my 2 pence into this.

My suggestion is the first code could be as simple as replacing the tank vent valve. IIRC this vents vapours built up in the fuel tank to the inlet plenum.

The trim codes sound like a bi-product of the non-oem MAF. Fitting an OEM unit will likely clear up those 3 codes.

[Olivergt]

OP, don't forget, you can run with the MAF disconnected if you want, it will use a default map, this will prevent lean running if you are worried.

I use OBD Fusion (Android) and a Carista bluetooth OBD2 bluetooth adapter for reading codes and real time data.

Carista:
https://caristaapp.com

Note: you don't need any of the Carista apps, and I have had a couple of cheaper adapaters which both failed.

Just found this video on how to test the Fuel valve for the 44 error.

https://www.youtube.com/watch?v=-Q5h1lBbH_s

Edited by Olivergt on Tuesday 15th September 17:52

[LLC24]

Olivergt said:

OP, don't forget, you can run with the MAF disconnected if you want, it will use a default map, this will prevent lean running if you are worried.

I use OBD Fusion (Android) and a Carista bluetooth OBD2 bluetooth adapter for reading codes and real time data.

Carista:
https://caristaapp.com

Note: you don't need any of the Carista apps, and I have had a couple of cheaper adapaters which both failed.

Just found this video on how to test the Fuel valve for the 44 error.

https://www.youtube.com/watch?v=-Q5h1lBbH_s

Edited by Olivergt on Tuesday 15th September 17:52

Cheers for that, the video was helpful, I’m at work now and so will use one of our multimeters to check that to see if that’s one of the issues.

[LLC24]

Shanksy87 said:

Throwing my 2 pence into this.

My suggestion is the first code could be as simple as replacing the tank vent valve. IIRC this vents vapours built up in the fuel tank to the inlet plenum.

The trim codes sound like a bi-product of the non-oem MAF. Fitting an OEM unit will likely clear up those 3 codes.

Okay I will check that. Do you know a good place to get an oem maf sensor other than bmw? £355 their parts department told me. I’ve had a little look and found the Siemens VDO for £280. I will spend it if I have too but I’d rather not if there’s a cheaper place you or anyone else may knows of?

[anonymous-user]

I bought a second hand genuine MAF from a breaker on ebay and works fine.
Think it was about 20 quid? Be cheaper to keep replacing them every few years with a second hand one than to buy a new one.

[Olivergt]

eezeh said:

I bought a second hand genuine MAF from a breaker on ebay and works fine.
Think it was about 20 quid? Be cheaper to keep replacing them every few years with a second hand one than to buy a new one.

I did the same for mine and it was/is fine.

OP, keep us posted on progress, people do check back every so often.

In general these are fantastic cars, there are a few weak spots, but I have found that they are normally quite easy to fix and there is a huge amount of help here on the web. (I have to admit though, some of the issues can be a complete bd to diagnose, but then when the culprit is found, generally easy to fix).

[LLC24]

Olivergt said:

eezeh said:

I bought a second hand genuine MAF from a breaker on ebay and works fine.
Think it was about 20 quid? Be cheaper to keep replacing them every few years with a second hand one than to buy a new one.

I did the same for mine and it was/is fine.

OP, keep us posted on progress, people do check back every so often.

In general these are fantastic cars, there are a few weak spots, but I have found that they are normally quite easy to fix and there is a huge amount of help here on the web. (I have to admit though, some of the issues can be a complete bd to diagnose, but then when the culprit is found, generally easy to fix).

Checked the valve as shown in the video you suggested but the resistance was 26 ohms which is pretty close to the value he had for the working part so I’m guessing it’s fine on my car too. Thanks for the suggestion though as I can now rule that out for the moment

[Olivergt]

Have you checked both the DISA Valve and the Idle control valve as well? These can throw lean codes from what i remember.

Let me know if you haven't and I'll send on more details on how to check/clean etc.

The DISA o-ring failure should have shown with the smoke test though.

[LLC24]

Olivergt said:

Have you checked both the DISA Valve and the Idle control valve as well? These can throw lean codes from what i remember.

Let me know if you haven't and I'll send on more details on how to check/clean etc.

The DISA o-ring failure should have shown with the smoke test though.

No I’ve not checked those although it does occasionally have a rough idle upon starting up but this always stops even after a very short drive. The idle tends to be worse upon start up the less I’m using the car as well. I may replace the DISA valve as a precaution at some point just becuase I don’t know whether it has been done or not. I have no clue where I’d find the idle control valve though. Thanks again for the help.

[Shanksy87]

LLC24 said:

Okay I will check that. Do you know a good place to get an oem maf sensor other than bmw? £355 their parts department told me. I’ve had a little look and found the Siemens VDO for £280. I will spend it if I have too but I’d rather not if there’s a cheaper place you or anyone else may knows of?

Elliot Cutter at Kirkcaldy BMW is my go to for OEM parts, give him a call: 01592 657842