Vag codes: doesn't seem good

[pit viper]

I've seen the first two pop up now and then. The rest are news to me.

Address 01 -------------------------------------------------------
Controller: 8D0 907 551 A
Component: 2.7l V6/5VT G02 0003
Coding: 06611
Shop #: WSC 06325
10 Faults Found:
17947 - Clutch Pedal Switch (F36): Implausible Signal
P1539 - 35-00 - -
17521 - Oxygen (Lambda) Sensor: B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent
17833 - EVAP Purge Valve (N80): Short to Ground
P1425 - 35-10 - - - Intermittent
17880 - EVAP Leak Detection Pump: Short Circuit to Ground
P1472 - 35-10 - - - Intermittent
17938 - Camshshaft Timing Adjustment: Short to Ground
P1530 - 35-10 - - - Intermittent
17955 - Boost Pressure Regulation Valve (N75): Short to Ground
P1547 - 35-10 - - - Intermittent
17697 - Boost Pressure Control Valve (N249): Short to Ground
P1289 - 35-10 - - - Intermittent
17529 - Oxygen (Lambda) Sensor Heating Circuit: B2 S2: Short to Ground
P1121 - 35-10 - - - Intermittent
17525 - Oxygen (Lambda) Sensor Heating Circuit: B1 S2: Short to Ground
P1117 - 35-10 - - - Intermittent
17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-00

[Rated S]

So what it looks like, though I could be wrong is:

EVAP is leaking - I think an untightened gas cap can do that.
Your 02 sensors are crapping out.
Your CAM Sensor is shitting the bed.
As well as your N75 valve.

[Unispeed]

Positive deviation man! You are probably getting throttle cut because of overboosting... change that n75 and pressure test at least.

[Boosted-S4]

got the same code for the o2 sensor!!! change both of them!!! also, ecs tuning has the N75 race valve for only 86 bucks!!! look into it!

[pit viper]

I've got a full set of replacement O2 sensors, I'll swap them out and see how that goes.
Where is the N75 located on this car? I've only had to hunt it down on a Beetle before.

[Unispeed]

Dont tell him to get the N75 race valve... if he as a picky tune like apr or abt you will get about 2psi boost deviation plus your spike at wich point you will get throttle cut. Also beware of ECS as they like to send out A4 N75 valves to S4 customers. You will notice that the valve body is black instead of bronze color.. if you order for them get the code right off the valve and make sure they send you that one... dont settle for anything else.

got the same code for the o2 sensor!!! change both of them!!! also, ecs tuning has the N75 race valve for only 86 bucks!!! look into it!

[BastardS4]

fuel pump relay.

[Rated S]

I've got a full set of replacement O2 sensors, I'll swap them out and see how that goes.
Where is the N75 located on this car? I've only had to hunt it down on a Beetle before.

#4 circle.

Thank AudiSportB5S4 for the pic.

[pit viper]

First off, I have a GIAC chip.

Ok, I cleared all the codes, swapped N75's with the one on my spare motor, and then went for another quick "jaunt" around the block. The car feels a little better, but at best like stock. I pulled the codes again after my drive, and only got

17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-00

It may be that others haven't had a chance to set yet, I don't know.
Anyway, what else should I check?

[Rated S]

First off, I have a GIAC chip.

Ok, I cleared all the codes, swapped N75's with the one on my spare motor, and then went for another quick "jaunt" around the block. The car feels a little better, but at best like stock. I pulled the codes again after my drive, and only got

17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-00

It may be that others haven't had a chance to set yet, I don't know.
Anyway, what else should I check?

Do you know how much you are boosting? Gauge or Vag-COM? That will tell if you're in limp mode, or have a boost/vacuum leak.

[pit viper]

since I am just getting used to the vag, how do I go about checking the boost with it?

[00s4slvr]

I have the race N75 in with my Giac x and im stage 1 and i have no throttle cut or nothing. Boost holds 15-17 spikes to 18-19 then back down to 15-17.

[Rated S]

since I am just getting used to the vag, how do I go about checking the boost with it?

Haven't logged with Vag-Com in a while but iirc it is block 115 to log boost. Log a couple pulls with that and then post them up.

[pit viper]

Ok, I screwed up the "make it to a graph" part, but you'll get the idea. The Y-axis is actually boost pressure in millibars, the X-axis is just time. I logged 2 quick pulls.

[zmw]

you need to flip that graph, the way it's laid out doesn't give us any idea about the actual values being requested versus actual...

[Rated S]

Yeah, boost should be on the Y (up/down) axis and change it to RPM, put on the X (left/right).

[pit viper]

Yeah, boost should be on the Y (up/down) axis and change it to RPM, put on the X (left/right).

It is, I just typed the labels in backwards. The Y axis is displaying boost in millibars (sorry, wasn't sure how to swap to psi), and the X axis is just over time, since I did more than one pull.

[Rated S]

Hope this picture helps.


You have a giant boost leak somewhere or something is going on (blown DVs/faulty n75/etc)

So you are requesting x amount of boost, but not getting ANY and it's cutting throttle. Check Throttle Body Boot, IC pipes, pressure test, and find that gremlin.




And I hope you're chipped, guessing your cities baro. pressure, you are hitting 17.5 psi (healthy GIAC chip, for example) so your requested boost is fine, something (or things) is hindering your actual boost.

[pit viper]

That's actually not throttle cut, that was me letting off the gas, slowing down, then doing another pull. But I understand the requested vs. actual boost part. And yes, I have a GIAC chip.

I swapped the N75, which got rid of some codes, but didn't greatly increase boost, so there must be another issue as well. The tbb and upper intercooler hoses are on, I'll have to jack up the car and check the lower's. Is there an easy way to tell if one or both of the dv's is broken?

[CONTROL ONE]

Well, have you done a boost leak test yet?

Seems as though you have a massive leak somewhere.

[Rated S]

That's actually not throttle cut, that was me letting off the gas. Is there an easy way to tell if one or both of the dv's is broken?

Oh thank god, that looked like horrible throttle cut. Lucky I guess it isn't.


yeah, you see the top vaccum hose (the smallest one?) Get one of those, pull of the one from the car and put your new one on. Take the other end and suck on it. If you can 'break' the seal with only your mouth then they are more or less likely bad. Also if/when you shift they sound like BOVs, they are bad./ But seeing as how little boost you have, you might not be able to detect it that way.

is your TBB stock or samco/bipipe?

[Rated S]

I just took a closer look at your log, and guessing your BAR reading is about 900 mbar and you hold steady at about 1250 mbar (roughly). That equals 350mbar (atmosphere pressure=900 subracted from your "boost" = 1250 = 350). And 350 mbar is about 5 psi, which would be limp mode.

[pit viper]

Is there a way to pull it out of limp mode without disconnecting the battery?

*edit* If it was in a limp mode, then the requested boost would show as low, correct?

The TBB is stock, but I pulled it off and checked it for any cracks or holes, and it's ok.

[Rated S]

You are correct =p.

[Daft]

Pit viper,

I just read this thread after commenting in the one you posted in the A6 forum. I thought that all the same codes came back.

Anyhow, since it's only positive deviation, it's certainly a leak.

You are going WOT and the boost map in the GIAC program is requesting full boost but, no matter how much duty cycle the N75 applies, the turbos cannot create the specified boost.

You definitely have a serious boost leak. As the boost rises in the IC piping, the leak opens and the boost levels stop climbing.

#1. You need to fix this ASAP. This is how turbos are ruined via overspin.
#2. You need to build and intake leak tester and get busy.

Go to Home Depot, buy a rubber plumbing coupler and a matching PVC cap to go on one end. Drill a hole for either a shrader valve or quick-disconnect chuck for an air line. Buy a 3/4" vacuum cap and shave the inside until it's about 7/8" ID. Then remove the PCV valve from the large silve Y-pipe on the top of the motor. Remove the MAF accordion from the Y-pipe and place your leak tester on that spot and clamp it down. Clamp the 7/8" ID rubber cap on the barb where the PCV was attached.

Loosen your oil cap. Set your compressor's regulator to 15Psi and pressurize the system. It is best to have the car on jackstands and have the belly pan off. Search around for escaping air and you should be able to locate the leak. Since you are dropping roughly 1000mbars of pressure it, is a sizeable leak. I think you'll locate it easily. Check the rubber IC pipes, the TBB, the hoses and clamps around the diverter valves. Vacuum lines are suspect too. You may only have a 1/2 tear in a hose and all that pressure is shooting right out.

The N75 appears to be working properly at this point.

[Rated S]

http://awe-tuning.com/pages/shared/p...ssure%20tester

To give you an idea what a pressure tester looks like for our Y-pipe.

[00s4slvr]

just buy the one form Vast performance its like $30 and start pressure testing!! or take it to a shop...