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**The_Jerbel** · 02-27-2010, 04:17 PM

Re: 11 Faults found. Now what??

You should boost leak test your system. That ABS code is nothing to worry about.

**vee_dubbin** · 02-28-2010, 03:15 AM

Re: 11 Faults found. Now what??

I would say you have a serious vacuum leak somewhere. Probably the PCV system if its a 1.8T. Misfires could also be related to fuel supply, and not just spark/ignition system. Sounds like you got a nightmare on your hands. I wish you all the luck...its an Audi...$$$!!

**aliencurv** · 03-01-2010, 12:12 PM

Re: 11 Faults found. Now what??

go for a drive with your vag-com hooked up . get onto a highway and put yourself into a high gear from a low rpm (so you're loading the car up). if you're going around around 40 km/hr in 4th or 5th gear is good. that'll put lots of load on the engine for a more accurate pull

do that and log measure block #15, #16, #115

the requested boost pressure at low rpm's under high load will be much higher then the actual; but once the turbo's catch up, they should be very close throughout the higher rpm. if they are considerably off, then that's a reason you could be misfiring <- boost leak

also, you can do the same run again with blocks #1, #115 & #31. #31 will tell you the afr with a simple calculation once you put the results in excel (afr = lambdadada * 14.7). if you are seeing high afr's while in boost, then you most likely have a dirty fuel filter. #1 will tell you the afr correction, that will tell you if it's an o2 sensor, confirm boost leak, or vacumn leak.

that should get you started, and give you a few ideas on how to diagnose future problems. you can post your log results and i can take a look at them for u also

PS, i should also add: everytime you are under the hood and beleive you fixed a boost/vacuuum leak; then reset your vag-com codes. that will clear your long and short term fuel trims for block #1. by clearing those values, over time you can see how off they are.

the long/short fuel trim is a way of correcting for failing sensors (o2/maf specifically), vacuuum leaks, clogged air filters and altititittude. the computer is programmed for a specific injector duty under various loads for ideal conditions of that engine. but, due to many uncontrollable reasons during closed loop (Regular drivin conditions) the afr will be slightly off. the computer recognizes this through the o2 sensors. it will create a "trend" correction percentage which is "long term trim". the short term trim is for immediate results that aids with gas milleage, engine reliability and pollution control.

the reason i'm typing this part is because if properly understood, you can recognize why "Gas saving devices and additives" are ****. the reason why is the final AFR is "demanded" and not negotiated. as an example, 3500 RPM, 80% load, 88% throttle, 40C IAT, 95F ECT, 3.3v MAF, etc etc has a final demanded AFR of 11.5:1.

the computer will do what ever it can to add more fuel, or remove fuel to see that AFR. unless the additive tricks the O2 sensor, you'll always use the same fuel ammount (Within accuracy of your o2 sensor). if the additive modified your afr (somehow magically) then you'll be runnin lean and good bye eengine

stoich for gasoline (most effecient burn) is 14.7 parts air to 1 part fuel. the lower the number, the richer it is. richness is used to "cool" combustion chambers under high load to prevent detonation and preignition, but steals horsepower. leanness is hot and powerful and adds horsepower but also adds heat and therefore is a cause of detonation and preignition.

stoich for E10 (mohawk's 94) is around 14.9 (i think). anyone with a chemical brain can tell me? all i know is, if i tune any of my cars on E10, then i can't ever run 91 gasoline under load/boost. anyway, you still see the final AFR on a gauge correctly, but your computer doesn't know it's E10 and therefore won't use it much. UNLESS the computer (on the highway) is monitoring the ignition timing, sometimes it'll keep playing with it to receive optimal results. in which case, you'll get a bit better milleage due to more aggressive timing (But same afr).

i guess i wrote that additional part because i was thinkin about afr when telling u how to diagnose the sensor and then i started thinking about ppl/hippies who tell me "gas milleage tricks". i tell them to shut up and go back to Hornby and play with linux and talk about how firefox protects our rights. damn hippies!

**Kordain** · 03-01-2010, 07:31 PM

Re: 11 Faults found. Now what??

id suggest having a passenger do the vag-com bit while your on the highway, you know, its much more.... social

**The Brice** · 03-01-2010, 09:36 PM

Re: 11 Faults found. Now what??

Originally posted by tactic12 View Post

10 Faults Found:
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 002 - Lower Limit Exceeded - Intermittent
17772 - Cylinder 4 Ignition Circuit: Open Circuit
P1364 - 004 - No Signal/Communication - Intermittent
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 002 - Lower Limit Exceeded - Intermittent
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 001 - Upper Limit Exceeded
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 001 - Upper Limit Exceeded
16685 - Cylinder 1: Misfire Detected
P0301 - 008 - Implausible Signal - Intermittent
16688 - Cylinder 4: Misfire Detected
P0304 - 001 - Upper Limit Exceeded
16686 - Cylinder 2: Misfire Detected
P0302 - 008 - Implausible Signal - Intermittent
16683 - Boost Pressure Regulation: Control Range Not Reached
P0299 - 002 - Lower Limit Exceeded - Intermittent
17743 - Engine Torque Monitor 2: Control Limit Exceeded
P1335 - 008 - Implausible Signal - Intermittent
Readiness: 0000 0000

************************************************** ****************************-
Address 03: ABS Brakes Labels: 8E0-614-517.lbl
Part No: 8E0 614 517 A
Component: ABS/ESP allrad 3429
Coding: 04275
Shop #: WSC 63351

1 Fault Found:
18256 - Please check DTC Memory of Engine Controller
P1848 - 35-10 - - - Intermittent

************************************************** ****************************-

I cleared the codes and will replace coilpacks in cylinders 1,2 and 4. Also, I've just replaced the MAF so I'd be surprised to see it again now that I cleared that code.

Does any of this have to do with my EPC light coming on and the car powering down until I turn off and restart the car? (Only if I've been using cruise control.)

Time for a new diverter valve?

And what's up with the ABS? I've had an issue twice where the brake lights came on, and one time it felt like the vacuum assist actuated a little bit.

Cheers!

Couple different issues for sure, I recently threw the same MAF fault as you have here on my A4 and was having identical misc. random misfires pop up from time to time as well. I was sure the MAF was the issue here as well so I too replaced it only to find the code continued to pop up.

So I ran some logs on the car and found my fuel trims were way out to lunch, STFT's ~+15 and LTFT's maxed out at +25, very lean! So upon snooping around my vacuum lines I found most of the connections under the intake were very loose and the lines were getting quite brittle so I replaced a couple of the lines and all of the clamps then voila good as new and no more MAF code. Like Vee Dubbin says sounds like a good vacuum leak(s) could be a good possibility in your case. Log Block 32 to see how your fuel trims are looking and go from there. Some issues will be related so hold off on replacing the coilpacks until you make sure you have no leaks in your system, good luck!

**PRY4SNO** · 05-02-2010, 03:25 PM

Re: 11 Faults found. Now what??

Update

I replaced all four coilpacks with Rev.D and noticed immediately a crisper start, smoother idle, and strong power in high gear, low rpm situations.

Been willing my cruise issue into nonexistence. Have Samco kit to install will get the bulk hoses and clamps from stealership when I go for my fob to get cut and install it all at the same time. Sourcing a new DV as well.

Finally got some logs, props to Colin.

https://spreadsheets.google.com/ccc?...5MGtWbEE&hl=en

https://spreadsheets.google.com/ccc?...MZmxRMVE&hl=en

**Pshrynk** · 05-02-2010, 03:32 PM

Re: 11 Faults found. Now what??

Get a second job?

**PRY4SNO** · 05-03-2010, 04:54 PM

Re: 11 Faults found. Now what??

Bump for help with logs...

**The_Jerbel** · 05-03-2010, 07:34 PM

Re: 11 Faults found. Now what??

Looks like your boost behaviour is a little out to lunch. I would start by testing 3 things- the boost/vacuum system with a boost leak test, the WG air line, the N75 valve (see if somebody you know has a known working one and swap it in for a couple of logs). Then I would also test your DV, and if it's a piston-style valve, clean and lube it.

**aliencurv** · 05-03-2010, 07:43 PM

Re: 11 Faults found. Now what??

your first log file looks like you had a higih load.. so maybe high gear? oh and i see you logged load too, so you can see how high it is. you probably didn't have boost because of the load. it looks like it took you 9 seconds to accelerate from 4k to 64k .. so i suspect high gear and that is why your boost levels are low

on your second log file, you have a misfire or you tapped the throttle at 6560 rpm, but your boost looks great compared to actual.

are you still throwing codes?

**The_Jerbel** · 05-03-2010, 08:14 PM

Re: 11 Faults found. Now what??

I think the boost looks wacky on both logs. Even under extremely high engine load, the actual boost should gradually ramp up to meet desired. The logs show very erratic boost behaviour.

**Disturbo** · 05-03-2010, 11:16 PM

Re: 11 Faults found. Now what??

EPC light coming on is a bad TB. Seen this lots

**PRY4SNO** · 05-04-2010, 11:03 AM

Re: 11 Faults found. Now what??

Originally posted by The_Jerbel View Post

I think the boost looks wacky on both logs. Even under extremely high engine load, the actual boost should gradually ramp up to meet desired. The logs show very erratic boost behaviour.

That's what it looked like to me, but I'm posting here for help because I'm no expert...

And thanks guys, the insight means a lot to me... even if I have to take it to someone for repair at least I know if I'm getting hosed and can help reduce diagnostic time.

I did some high load runs and some 4k-redline(ish) runs in 3rd gear.

So I need to test the boost/vac lines and N75, and my DV is an OEM Bosch 710N. I'm in the process of lining up a replacement (Samco, and Forge if I can't find one soon-ish). Boost gauge (dual function VEI with oil temp and boost/vac) will be installed... once I figure out how to get the oil temperature sender into the block and wire everything. That should help a bit.

Haven't thrown new codes since I cleared them a week or two ago.

Can I clean and realign my TB or do I need a new one? BTW, I've been using the cruise here and there -- willing it to work -- and it has been fine thus far.

**The_Jerbel** · 05-04-2010, 11:15 AM

Re: 11 Faults found. Now what??

EPC light can be a lack of communication between the TB and the ECU, or it can be a bad connection between the ECU and the gauge cluster (typically caused by a faulty ECU chip or bad software on the ECU).

You're on the right track with your testing procedure. You can clean and align the TB if you want, it never hurts, but if the ECU cannot communicate with it, the alignment and cleanliness won't affect that.

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11 Faults found. Now what??

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