Check Engine + Vag codes - Too Lean/Implausable

[ulfilias]

Hi Guys,

I have a few engine codes left from vagcom, which i guess are keeping my check engine light on (I regularly look under the bonet and yep. Its still there)

17549 - Load Calculation Cross Check : Implausable Value
17536 - Fuel Trim: Bank 1 (Mult): System too lean
17538 - Fuel Trim: Bank 2 (Mult): System too lean

Doing some searching i found this http://www.tyresmoke.net/forum/audi-...ror-codes.html with our very own Tony....But no solution

In other checks cleaning the MAF sensor comes up and i've did that the other day, not that it looked that bad. I guess it may be worth testing the performance of the MAF, VAGCOM ??? but i'm not sure what i'm looking for and searching on 3 letters is tricky !

Any ideas, hints pointers ???

Ta,
Lee

[Just_Ben]

Sounds like a failed air mass meter or air leak on the inlet ,manifold.

Check the air mass meter on live data (measured value blocks) on VAGcom. Look for the set of results displayed in g/s. With the car stationary, rev the engine, briefly with full throttle, allowing atleast 5000rpm. You should be seeing an output of atleast 190g/s. It will prob be about 45-50g/s at idle.

If the figure is higher no worries but if less than this you need an air mass!

Check the inlet manifold bolts as they come loose but also they are prone to breather pipes and the Suction Jet Pump can fail and allow the ingress of unmetered air.

ANy ofthese faults give the issue you have but it MUST be sorted as this can shag the 'box! The gearbox ECU uses air mass signal to calculate torque input so it must be corrected fairly quickly mate

[ulfilias]

Hi There,

Vagcom, Engine. Measure block. Group 003

RPM 760 , Mas flow 6.39 g/s , load 2.4
rpm 5000, Mas flow 30 gs, load 12

This is in park.

Seems exceedingly low ???, but does mimic the rpm

ta,
Lee

[ulfilias]

Hi There,

Looking at replacing the MAF.

VAG no. 077 133 471 K
Bosh 0280218067

There are new ones on ebay -http://cgi.ebay.co.uk/Mass-Air-Flow-Meter-AUDI-S8-4-2-Quattro-00-02-AVP-MAF-/180355028943?cmd=ViewItem&pt=UK_CarsParts_Vehicles _CarParts_SM&hash=item29fdff57cf For about £140 delivered for the complete unit.

However when i had mine out to clean i photographed the component parts and there is a bosch number f00c2G2047 on the actual air sensor itself.

Which comes in at £54 on ebay - http://cgi.ebay.co.uk/NEW-Air-Flow-M...item3ef7eaebb0

So i think i'm going to head down that route

[ulfilias]

Ok. I love EBAY. That £54 sensor had a best offer or BIN buttons, i thought i'd be cheeky and say £40 and it could always be pushed up. But no. Instant acceptance. *WOO*

[Conan_the_Librarian]

That's a result. I replaced mine recently and it cost a small child. If it is indeed a Bosch part please post deatils.

[ulfilias]

Hi Conan,

Alas the replacement sensor part at £40 is not Bosch. Shame but it will give me a chance to test if it is the MAF that is causing me a problem. The full unit at £140 does indeed claim to be a Genuine Bosch one.

The non bosch sensor part does come with the anti-tamper torq bit which i thought was a nice touch and is sealed. But definatly a white box type item.

Will see what performance figures i get later when i swap it out and if we clear some of the codes.

Cya,
Lee

[Architex_mA8tey]

Hi Lee
FYI the MAF I just replaced in mine was a genuine VAG one through TPS and it was something like £111 + VAT so check around for a few more prices
Cheers

[ulfilias]

Originally Posted by ulfilias

Hi There,

Vagcom, Engine. Measure block. Group 003

RPM 760 , Mas flow 6.39 g/s , load 2.4
rpm 5000, Mas flow 30 gs, load 12

This is in park.

Seems exceedingly low ???, but does mimic the rpm

ta,
Lee

New maf sensor :

RPM 760 , Mas flow 7.20g/s , load 2.4
rpm 5000, Mas flow 45gs

Hmmm....still seems low.

[Architex_mA8tey]

could possibly be a duff new one Lee - it has been known