DTC P0103-001 and P1074-001 "Mass Air Flow Sensor : Signal too High"

[42TT]

Hi,

Would appreciate input as to what could cause the following errors:

16487 - Mass Air Flow Sensor (G70): Signal too High
P0103 - 001 - Upper Limit Exceeded - Intermittent

17482 - Mass Air Flow Sensor 2 (G246): Signal too High
P1074 - 001 - Upper Limit Exceeded - Intermittent

Thanks
42tt

[skiwi]

given that it is both maf's normally you would check for leaks. have you been working on them?

intermittent errors usually should be cleared and checked periodically

[42TT]

Skiwi - Yes i have done some work on the car and the MAF's are brand new. I also still have the MAF variance which I cant seem to fix once and for all

42tt

[skiwi]

ok - clear the codes and see if they re-occur, chances are that they won't...

[42TT]

Skiwi - One step ahead in that regard cleared the codes and the DTC's come back, the ESP light comes on in the upper RPM's and stay on until the rev's drop.

42tt

[skiwi]

the esp light???

self test completes (light on then off on engine start)
light off until high revs then on?

very strange.....

[42TT]

Skiwi - Yeah it is as if the engine is ecu is telling me that the MAF's are reading too high with the ESP light.

Doesnt matter how many times I reset the codes they keep coming back with enthusiastic use of the throttle of course ;)

42tt

[RS6Driver]

Not very good advertisement for your 'cooling upgrades' you posted in another thread...

[42TT]

RS6Driver- Why do you say that? I have had the MAF variance issue for quite some time besides im asking for input into a problem has nothing to do with my car overheating.

Skiwi - I think i have worked it out well sort of. I have removed the crank case breather system and blocking off the t connections at either side of the throttle body aswell as the rear connections where the airflow meters sit in.

The MAF's now read dead on. The car runs smokey which is to be expected i think this could also be causing the MAF error will keep you posted

Thanks
42tt

42tt

[O.CT USA]

Sometimes when MAF code and ESP all come up it could be the MAF that is faulty. Log block 003

[42TT]

OCT USA - I wish it was that simple. Both MAF's are brand new and the error is being logged for both MAF's.

I know that if you leave the MAF's unplugged the ESP light stays on, I assume the ESP light coming up is when the MAF's voltage is exceeding their limit.

Like i said earlier i have traced my MAF variance problem to the crankcase breather system, by removing it from the engine and blocking the connections the MAF's read nearly identical, just a shame that i cant leave it like this.

What is the name for the part that sit at the front of the engine near each rocker cover that looks like valves of some sort they are part number 034 129 101 c?

What info will MB003 give?

Thanks
42tt

[skiwi]

very strange, some sort of eletrical interaction must be at work - there are "esp on" faults casued by electrical issues.

check for loose connections and re-seat connectors at the rear of the engine is all i can think of....

[42TT]

Skiwi - Can you explain to me how the crankcase breather system works?

There are two T-junctions at the front of the engine either side of the TB one seems to have vacum/suction (right side) while the other releases blow-by (left side).

And on either side of the engine there is some sort of valve what do they do?

I have circled the t-junctions and valves in the pictures below.

I have narrowed done my MAF variance to this area as I have by-passed it and the MAF's read perfectly the same but the car runs rough and I find the crakcase is building up pressure.

42tt

[skiwi]

the areas you have circled are the 2 pressure limiting valves (1st image) and the non-return valve (2nd image)...

the crankcase breather comprises 2 pressure limiting valves, and a non-return valve with their associated hoses. unlike with the 2.7tt, there is no distributor piece, the 4.2tt makes do with hose connections.

the oil vapours and “blow-by“ gases from the cylinder heads and the crankcase converge at the non-return valve and through that to the pressure limiting valves. the pressure limiting valves and the non-return valve control the return of these vapours and gases to the engine, depending on the intake manifold pressure. <o>

1) </o>vacuum in intake manifold: the oil vapours and “blow-by“ gases return via the non-return valve to the intake manifold. <o>

2) </o>charge pressure in intake manifold: the oil vapours and “blow-by“ gases return via the pressure limiting valves. <o>

</o>the pressure limiting valves limit the vacuum in the crankcase. if the vacuum in the crankcase exceeds a defined value, the diaphragm is drawn over the connection against the force of the spring and closes the connection. the valve is designed in such a way that it allows a small quantity to pass through when closed. this prevents the engine oil being drawn into the intake tract . <o></o>

[42TT]

Skiwi - Okay, there is a very strong vacum at the non-return valve at idle which by your explanation is normal. So somewhere between the non-return valve and the limiting valves is the leak.

Can this system be by-passed so i can log the car without it burning oil?

42tt

[skiwi]

i wouldn't bypass it, easier to fix it in reality...

are the maf values off only at idle or also at higher rpm? reason is that the non-return valve at idle pulls the vapour into the manifold, but with boost, the pressure limiting valves are the key component and take the fumes and feed them in upstream of the compressor.

you might have a leak in the valve causing bypass when there shouldn't be any or between the centre of the pressure limiting valve (the return circuit) and the upstream turbo connection. any leak in that circuit could be a tear pretty hard to detect. if you have access to an air compressor, easy enough to check with engine off...

[rmedy23]

what was the update to this error?
what caused the error code?

[snoopra]

what was the update to this error?
what caused the error code?
This dude was banned for scamming forum members.

[SensoRS6]

I'm having the same problems now, anyone got any ideas for me?

[Kgnast]

SensoRS6.... are you chipped? I've seen this before, and I see it on my car. Under full WOT throttle, at upper RPM range, the ESP light comes on. Drops off when rpms lower. Happens like clock work every time I stand on it to red line. Apparently, the chipped cars are flowing/sucking more air, and the upper limits of the MAFs are exceeded. This has been discussed many times here at RS6.com. It has something to do with how MAF's measure air flow by putting through a certain voltage to heat the MAF wire filament. As more air flows and the wire-filament cools, more voltage is needed to keep it at a certain temperature. The amount of voltage needed tells the ECU how much air is flowing. At some point, the car does not have the ability to send enough voltage to warm the filament, thus throwing the DTC.

Am I way off base here? Anyone else want to chime in?

[SensoRS6]

I am chipped, so that does make sense. Don't care about the light, I just tell everyone that I have so much power that traction control can't handle, lol. That part that worries me is a slight hesitation in the power, like a loss of fuel, something like that. But I just cleared the faults and haven't felt the hesitation again. I don't want to push it while there might be something wrong, but we are getting somewhere. Thanks!

[lswing]

I am chipped, so that does make sense. Don't care about the light, I just tell everyone that I have so much power that traction control can't handle, lol. That part that worries me is a slight hesitation in the power, like a loss of fuel, something like that. But I just cleared the faults and haven't felt the hesitation again. I don't want to push it while there might be something wrong, but we are getting somewhere. Thanks!

I had a hesitation issue with power, I would call them bumps along the way to redline, or hickups. The car was running lean and pulling timing every 500rpms, and pulling boost/power at the same time. If you're getting to much air in maybe it's causing the same thing? What do you data logs say? Do a log a get timing, boost, maf...you have ross-tech vagcom right?

Maybe after you clear the faults it takes the ecu time to adjust to the lean condition and eventually starts to prevent knock...

[SensoRS6]

I only have a friends generic cord, not the actual VAGCOM. But I can try to do a log, where is it in the software? Thanks for the help.

[lswing]

Hopefully it works, the VCDS software is invaluable...

Always start by going to Options, Test, Save.

Select Control Module, then Engine, then Measuring Blocks. A few other details with saving to a log file, location.

Use 3-timing, 112-egt, 115-boost, for starters. 31-lambda can be added in another time, reads the front O2 for fueling.

To upload a log here, trim out all the extra tables. Save as webpage from excel. Open in a browser and select with cursor, then paste into a post here.

[10SecS4]

No, you're forgetting again that he had the hesitation and cylinder #8 misfire before he got the car tuned.

SensoRS6, I would replace your spark plugs and see if the misfire goes away. I'd also do a pressure or smoke test to check for boost leaks. These are the two most common problems which would cause an intermittent hesitation.


I had a hesitation issue with power, I would call them bumps along the way to redline, or hickups. The car was running lean and pulling timing every 500rpms, and pulling boost/power at the same time. If you're getting to much air in maybe it's causing the same thing? What do you data logs say? Do a log a get timing, boost, maf...you have ross-tech vagcom right?

Maybe after you clear the faults it takes the ecu time to adjust to the lean condition and eventually starts to prevent knock...

[SensoRS6]

Code hasn't come back since I changed the Coil to Cylinder 7. I did blow off the boosted side of the intake, hose right after the intercooler. I made sure that is nice and tight now. I think it might have been a couple of things, the coil pack and the boost leak. I will run a log tonight and see what shows. Thanks again for everything.

[lswing]

No, you're forgetting again that he had the hesitation and cylinder #8 misfire before he got the car tuned.

SensoRS6, I would replace your spark plugs and see if the misfire goes away. I'd also do a pressure or smoke test to check for boost leaks. These are the two most common problems which would cause an intermittent hesitation.

Not saying it's the tune, just thinking there is an air leak causing the disturbance if it's not the plugs or packs. +1 on the smoke test, cheap, easy, and works well. Still think it would be good to see what's going on with some of the engine settings.

[lswing]

Any luck? This would be well worth it when you get a chance. http://www.ross-tech.com/

[SensoRS6]

Any luck? This would be well worth it when you get a chance. http://www.ross-tech.com/

Went to do it last night, and the laptop died right as we took off. Might try this weekend. When I input these, 3-timing, 112-egt, 115-boost, do I press go after I input, then start? and then drive normal? hard run? how long should I go?

[lswing]

Went to do it last night, and the laptop died right as we took off. Might try this weekend. When I input these, 3-timing, 112-egt, 115-boost, do I press go after I input, then start? and then drive normal? hard run? how long should I go?

On that same input screen, make sure to click the turbo button up top, logs much more data. You could also try logging MAF, you'll find it there. Go to set, then start, and it will ask you to pick or name a new log file. Once it's working you can click stop, then resume, to get multiple logs in one data sheet. Use tip, 3rd gear preferred, 2,500 up to redline if you can, foot all the way in...don't hit the kickdown switch.