Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: PLANETNZ on 01 June 2013, 06:46:34

Title: Weird code 73 (low voltage MAF)
Post by: PLANETNZ on 01 June 2013, 06:46:34
Hi guys


my question is, with my car (99 2.5 fl) generally is a low voltage code 73 a stuffed maf of something else down the line?

The weird code 73 developed the other day after i had the car parked on a rather steep up-hill incline.
immediatly after starting and backing down the hill the car started running like a POS. managed to coast down the hill left it for a bit tried re-starting and still running like crap.
Dissconnected the MAF and away it went, ran heaps better and weird part was the MPG went down IE; much better! I figured at the time maybe some oil residue or something from being on the hill had contaminated it somehow
A few days latter I removed it (maf) and cleaned with circuit cleaner, blew it off (quitely) with compressed air. Plugged the obd into the laptop "code73" cleared it ran it again still there (after a couple of times)
The maf voltage is .11V and very little movement in the intake vacumme
Would the fact there is movement and voltage mean that the maf is Ok and its possibly something else??  I cant find and vacuum leaks etc.  Also, would the "improved" mpg shown on the computer be because the maf is now unhooked??

i have of course searched through here and still are but maybe someone has come accross this before!?

Cheers

boycey
Title: Re: Weird code 73 (low voltage MAF)
Post by: PLANETNZ on 01 June 2013, 07:30:06
..just on the mpg, the car generaly runs about 8.5 k/pl but occasionaly runs down to 7.1 (about 18mpg) this is general around town running avr speed is 22kph.
The car has has new / recent dis pack, leads, plugs, breathers icv cleaned etc etc. I kinda figured at the time one of the o2's was getting a bit lazy.
until 2 years ago the car was immaculate but after our roads here have turned into goat tracks after a couple of good earthquakes its kinda gone down hill a bit.
Since then the cats have also been removed after the exhaust system has had more hits than Elvis. 
Would a malfunctioning maf cause the poor mpg or do they just fail rather than play up?, could it (maf) have been doing this for a while??
open to ideas!
Title: Re: Weird code 73 (low voltage MAF)
Post by: noel on 01 June 2013, 08:34:27
i would say your maf needs replacing tbh,and as for cleaning it that's not always a good idea as they are very sensetive. :y
had a similar fault with mine changed maf for a genuine bosch one problem sorted :y
Title: Re: Weird code 73 (low voltage MAF)
Post by: symes on 01 June 2013, 09:00:25
mate I reckon you got same problem I had-MAF is failing  :'( Unfortunately would not recommend anything -except fitting another MAF-Bosch-not cheap pattern part as they last days only :(
Title: Re: Weird code 73 (low voltage MAF)
Post by: TheBoy on 01 June 2013, 10:32:12
Do you have the facilities to read the live data, as the ECU reports it?

If so, post up the idles kg/hr reading...
Title: Re: Weird code 73 (low voltage MAF)
Post by: dbug on 01 June 2013, 22:23:42
Replace the maf mate - cleaning it is usually the kiss of death for it mate ;)
Title: Re: Weird code 73 (low voltage MAF)
Post by: symes on 01 June 2013, 22:25:46
Replace the maf mate - cleaning it is usually the kiss of death for it mate ;)
+1 :y
Title: Re: Weird code 73 (low voltage MAF)
Post by: Kevin Wood on 03 June 2013, 13:54:12
Check for intake air leaks before changing anything. Remember, the code is telling you that the value from the MAF is lower than engine operating conditions suggest it should be - not that the MAF has failed!
Title: Re: Weird code 73 (low voltage MAF)
Post by: dbug on 03 June 2013, 14:04:59
Probably has failed now - op cleaned it ;)
Title: Re: Weird code 73 (low voltage MAF)
Post by: Kevin Wood on 03 June 2013, 14:06:45
Probably has failed now - op cleaned it ;)

Could well be. :y
Title: Re: Weird code 73 (low voltage MAF)
Post by: PLANETNZ on 04 June 2013, 03:09:37
yea yea i know..i cleaned it my fault!:)  so do these things just crap out or can they play up??. One of the reasons im asking is the fuel economy "seems" to be better now!

IE: was this a fault thats been there for a while and not shown until now??
Title: Re: Weird code 73 (low voltage MAF)
Post by: Kevin Wood on 04 June 2013, 13:31:50
They do tend to deteriorate over time. Eventually, the ECU has wound too much fuel trim on to compensate that it starts raising codes and that's when the symptoms start because it has reached the limit of fuel trim.

Having said that, the non-DBW MAFs tend to be moe reliable.
Title: Re: Weird code 73 (low voltage MAF)
Post by: PLANETNZ on 15 June 2013, 21:31:09
Cheers guys, im going to plug the laptop back into it today and see if any of thereadings make any sence but with a cracked screen and and now this its about to get parked up as the cost to repair isnt worth it.
 Im thinking about (seriously) coming over and chucking a couple of Mercs / bmw's into a container and shipping them back here as they are half the price in the UK at the moment!
one question, has anyone posted or thought about posting a set list of "normal" parameters rather than just in individual topics?
Cheers
Title: Re: Weird code 73 (low voltage MAF)
Post by: TheBoy on 16 June 2013, 09:48:33
As Kevin Wood implies, 2.5/3.0 MAFs tend to be pretty robust, far more so than the 2.6/3.2 ones.

The fact you've cleaned it, it probably does need a mew MAF now anyway, but that might not be the root cause of the problem.
Title: Re: Weird code 73 (low voltage MAF)
Post by: symes on 16 June 2013, 10:47:12
Check plug on EGR-this can cause your code problem-if you change MAF and still same ;)
Title: Re: Weird code 73 (low voltage MAF)
Post by: PLANETNZ on 26 July 2013, 07:37:33
Received a cheap new Chinese MAF today: about 30UK pound plugged in and all good, actually the bloody car has never run so good!  One thing i did notice though and im not to sure was that the old Bosch unit doesnt have the "Hot wire" screen in it? not to sure...  Very weird how the fault originally happened bu all good now!
Title: Re: Weird code 73 (low voltage MAF)
Post by: Marks DTM Calib on 26 July 2013, 08:20:02
My advice would be avoid the cheap pattern items.

The 2.5/3.0 MAF's are mega reliable and only generaly fail when they have been psised with, consequentaly there cheap second hand and will last much better than the clones.

Whats more, they are used on many different engines to.

Title: Re: Weird code 73 (low voltage MAF)
Post by: PLANETNZ on 27 July 2013, 06:27:05
Ok, a new twist!. This might actually be worth reading!
After finally "clicking" that I was trying to use a Vag-com emulator instead of my "My Naff Code Reader"  (major brain / beer fade) i managed to bring up the same 73 code on "My Naff Code Reader" but noticed reading the blocks that the new MAF was still measuring?.
I cleared the codes..still same problem(s) wont run more than 5 sec. checked the codes again, nothing, all clear. so just out of interest cleared them again and F me the friggin thing fired into life(Car) and is back working again like a new one!!  WTF!?

So going back to all the member's who have replaced MAF's that have been replaced again and again because of this, something is up..

OK, with all these research and reading here the one thing that comes up more often than not is a second hand MAF "seems" to work on more occasions than a new one, either clone or original Bosch (sorry if im boring im trying to figure this out now in my own head as well!)
OK, when i originally plugged in my new "clone" direct from China the car ran like a dream, the fuel figures have never been better and a totally changed animal;
then it just didnt work; after trying to start next morning, nothing  back to square one. Confused.

OK Q: how adaptive are the ECU's in these cars???  is it possible when we put in a new MAFand because of the "much improved figures" with a brand new MAFthat the ECU is getting all kinds of confused comparing the new figures to the old and thinking "F this, to hard..shut down!?" are the "old ones working more often than not because the trim figures are closer to what they were originally?  Fuzzy logic??

I dont know these systems at all so I am just guessing. I have no doubt this fault is going to happen again if not tomorrow the next day so i will record the "My Naff Code Reader" readings and compare. but i bet my ass that these faults will slowly disappear!

Thoughts??

Title: Re: Weird code 73 (low voltage MAF)
Post by: PLANETNZ on 27 July 2013, 06:28:28
(why is this site changing my "My Naff Code Reader" to naff!???)  mines an original version!
Title: Re: Weird code 73 (low voltage MAF)
Post by: henryd on 27 July 2013, 10:28:07
(why is this site changing my "My Naff Code Reader" to naff!???)  mines an original version!

Most of them aren't hence the world filter cuts in as no discussion of the clones is allowed here :y
Title: Re: Weird code 73 (low voltage MAF)
Post by: Andy H on 27 July 2013, 10:43:54
(why is this site changing my "My Naff Code Reader" to naff!???)  mines an original version!

Most of them aren't hence the world filter cuts in as no discussion of the clones is allowed here :y
I think the original developer "Autom3" has a distribution agreement with UK suppliers to distribute the same software as Vaux-Com in the UK.

http://www.ilexa.co.uk/diagnostic-tools/vaux-com.html (http://www.ilexa.co.uk/diagnostic-tools/vaux-com.html)