A4 quattro 3.0L driving cycle

[audi-owner]

completed repairs last weekend and am now driving the car trying to obtain ready status from all the OBD built-in tests so the car can pass state emissions.

according to the TOAD scanner, the only test that is not "complete" is the catalyst test.

does anyone know what the "driving cycle" is for the a4. In particular, which cycle phase will get the OBD to complete the catalyst test.

thanks....

[Furly]

You can try to force readiness with vcds. Or drive it for 100-200 miles with a good amount of highway driving. It took 200 miles for my B8 A4 to set readiness after clearing stored codes. The B6 i never had to smog it after clearing codes or disconnecting battery.

Did you replace the cats? If they are bad the readiness wont set.
Also what state are you in?

[old guy]

More than you ever wanted to know about readiness. Page three gives the drive cycle information to reset readiness. Follow it to the letter and it usually works. At least it does for me. Clicky click®

[audi-owner]

thanks O.G. I had already found that document but was concerned that it was too tied to snap-on to be applicable.
since you recommended it, I am not concerned any longer.

worked out good. did the 3 minute and 5 minute cycles as best I could with traffic and was able to get the OBD to complete the catalyst test.

now off to the test center to complete this activity.

regards...

[audi-owner]

It took 200 miles for my B8 A4 to set readiness after clearing stored codes.

shouldn't take that long. I would suggest you read the first 4 pages of the document O.G. referenced.

for some of the tests, it requires the car to perform a couple of run/stop cycles with adequate time for the engine to complete cool before restarting...

Did you replace the cats? If they are bad the readiness wont set.
Also what state are you in?

Catalytic converter was not replaced....
after using the drive cycle diagram in the document O.G. referenced, the catalyst test completed. It took about 10 minutes total drive time at 55 MPH.

state is IL

[imnuts]

The driving cycle should be the same for every car with OBDII, regardless of make/model. It is a standardized emissions test setup by the EPA that all manufacturers have to follow.

[ErikG]

Page 3 has the recommended routine, takes about 15 mins and will run every test. Verified a secondary air system code was fixed with this method.

-E

[pablolizarraga]

Page 3 has the recommended routine, takes about 15 mins and will run every test. Verified a secondary air system code was fixed with this method.

-E

Researching how to troubleshoot my SAI fault code. What was your fix?

I think I've narrowed mine down to solenoid or combi/EGR valve as being the problem.


Sent from my iPhone using Audizine mobile app

[ErikG]

Pablo, there is a guide on here for the replacement of all the vac lines and hoses. i looked at that to get my bearings about what and where the vac lines when. I found that someone had pretty much left some vac lines disconnected, and had no where to go. So i followed the guide to replace the vac lines with new ones following the schematic for check valves and 3 way tees and so on. That solved the problem.

So in other words, any vac leak will be the problem. One thing that i did was systematically take each connection, and suck on it. If it resists the vacuum you create, everything down stream from that is probably ok.

Link to the guide here: http://www.audizine.com/forum/showth...ne-replacement

I bought the car knowing it had some minor issues, this being one. The others were a dipped headlight issue and the other was it needing timing belt which i did myself a few weeks ago.

Does the air injection pump come on when the car is started? that was my problem. Item 12 in the second image in the post i linked to was not getting vacuum which is the vac switch to turn the air injection pump on.

[pablolizarraga]

Pablo, there is a guide on here for the replacement of all the vac lines and hoses. i looked at that to get my bearings about what and where the vac lines when. I found that someone had pretty much left some vac lines disconnected, and had no where to go. So i followed the guide to replace the vac lines with new ones following the schematic for check valves and 3 way tees and so on. That solved the problem.


Does the air injection pump come on when the car is started? that was my problem. Item 12 in the second image in the post i linked to was not getting vacuum which is the vac switch to turn the air injection pump on.

Thanks for the info Eric. That's the post that led me to looking into the functioning of the Changeover Valve (COV) on intake manifold. I've replaced the vacuum lines that had disintegrated. Last night I finally got around to doing some shadetree mechanic diagnostics.



Pump does turn on on cold start. I checked by pulling hose #6 from air box as I wanted to make sure that there was sufficient suction even though pump sounded like it was on. I've heard that air pump rivets can be responsible for leaks at pump. So pump is on and there is suction.

Then I basically did a lot of sucking. I replaced hose #20 leading to solenoid with an extra vacuum hose and sucked. Used another line as a stethoscope on each combi valve while I "artificially created a vacuum" to confirm that they clicked open. They did click.

I then tried creating vacuum on solenoid (#26 on diagram) but couldn't determine if they function because they also require electrical input. Then... I remembered that over the summer I had swapped the solenoid leading to the COV with the one above the manifold (#26)!!! I'm pretty sure the COV solenoid was responsible for non-functioning COV (even though it would click) and now it's been responsible for my SAI fault code.

Swapped solenoids and sure enough my COV doesn't work. So now I have the functioning solenoid at #26. I tried drive cycle to test if SAI now functions properly but didn't get to complete it. However, after the incomplete drive cycle, I went from this



to this


I'll be buying a new solenoid but I'm just hoping that A) more driving will clear the remaining readiness monitors and that B) driving since summer with a non-functioning SAI solenoid didn't do damage. My research has led me to horror stories about the price and the PITA it is to replace CATs. Crossing my fingers.





Sent from my iPhone using Audizine mobile app

[ErikG]

Pablo, good luck. It seems you are on the right path. Unfortunately i dont know what else to suggest. As far as damage is concerned, the SAI is only there to heat your cats up on a cold start. There shouldnt be too much damage done there. But thats me making a few assumptions. If you follow the driving cycle, that will run through all tests. I had cleared a code a while back and drove it for a few days (70-85 miles) with no returned codes, thought i was in the clear. Took it for a smog and it failed due to all readiness tests had not yet been run. By following the driving cycle, i passed all readiness tests in ~10 miles and 15 or minutes.

-Erik

[pablolizarraga]

Thanks for the info Eric. So you can have a repaired and fully functioning SAI but if you don't do the drive cycle to clear the codes before the smog, it won't pass?

I did another readiness scan this morning after 45min street driving and now I'm down to 2 failed readiness tests; Oxygen Sensor and Secondary Air Injection. Strange thing though, I'm not getting any engine fault codes for O2 sensor or SAI. Still crossing my fingers that maybe more driving will clear these last two codes. Thanks again for your input. Much appreciated.



Sent from my iPhone using Audizine mobile app

[SJorge3442]

Thanks for the info Eric. So you can have a repaired and fully functioning SAI but if you don't do the drive cycle to clear the codes before the smog, it won't pass?

I did another readiness scan this morning after 45min street driving and now I'm down to 2 failed readiness tests; Oxygen Sensor and Secondary Air Injection. Strange thing though, I'm not getting any engine fault codes for O2 sensor or SAI. Still crossing my fingers that maybe more driving will clear these last two codes. Thanks again for your input. Much appreciated.



Sent from my iPhone using Audizine mobile app

Its not that they are failed, they are just incomplete. I notice you're in LA. The SAI test I believe likes colder ambient temps to run the test as a FYI. Have you tried forcing readiness in VCDS? Its something the full program is capable of. I did it two years ago to get my car through inspection.

[pablolizarraga]

I only have VCDS-Lite but after paying $45 to an independent shop to run output tests (e.g. Pump, relay, fuse) I could've paid about $50 more to get my VCDS-lite registered and done the output test myself.

I feel like I should get some kind of "SAI Certificate of Interwebs Knowledge" with all I've researched and learned. You guys have been very helpful.


Sent from my iPhone using Audizine mobile app

[pablolizarraga]

The SAI test I believe likes colder ambient temps to run the test as a FYI.

Not sure if cooler temps helped, but...



I'll probably create a thread w/ a link to compile the resources (including this one) I used to understand and troubleshoot this SAI. I think what made the difference for me was that I had cleared the Fan Control Module fault I've had for a while the night before so that I had a better chance to start the drive cycle the next morning with no fault codes.

In the morning, i followed drive cycle. While idling (in drive position), I verified FCM code was not present. I then switched to readiness screen and followed procedure. I didn't even get to complete the 55mph for 3 min. because all readiness monitors had passed!

What I learned;
1) Although I was passing more readiness monitors after a day's driving, I would clear my FCM fault every day when I'd also check to see if I had passed more readiness monitors. Doing so was a mistake. After more research I realized that clearing codes would put me back square 1 with the same failed readiness monitors I originally started.

2) Follow cycle instructions to the "T". There's fine print in the graph w/ additional instructions that aren't in text that specify a) Idle in DRIVE, b) Rear defroster ON

I'm hoping that readiness maintains when I'll have it smogged tomorrow.

This forum has saved me once again!



Sent from my iPhone using Audizine mobile app

[ErikG]

Good work on figuring everything out. And yes, if the readiness tests have not been completed the smog will fail. The first time i had it checked, the tech said he wouldnt charge me for the smog since all he did was plug into the odb2 port and found the readiness tests hadnt been completed and gave me a copy of that driving cycle guide. And yes, follow it to a T.

good on ya!
-Erik

[pablolizarraga]

Thanks Erik. Couldn't have done it without this forum or...

this info...
https://youtu.be/Zj-_bAiPq9Y

this walkthrough...
https://youtu.be/Hfh1wK0UlKo

or, this guy.
https://youtu.be/rantuJlJtdc


Sent from my iPhone using Audizine mobile app

[abcxyzzz]

Resurrecting an old thread...

I'm trying to do the drive-cycle to pass the smog test in 2004 A4 Quattro 3.0L avant All monitors are passed except for CAT.

In the drive cycle instructions on page 2 and 3 of this document https://www1.snapon.com/Files/Diagno...CodeCharts.pdf the step for CAT is stage 7 which is to cruise steady state for 55 - 60 mph for 5 mins. Can i just do this step 7 without all the prior steps in the sequence listed? Also there was a note that says:


NOTE: If the CAT is marginal and the battery was disconnected prior to
the Drive Cycle, it may take up to five separate Drive Cycles in
order to determine the state of the CAT.

which presumably means I have to do multiple "cruise steady state for 55 to 60mph for 5 mins" up to 5 times.

Please advise.
Thanks!


Stage 1: Cold Start—The ECM determines the presence of a cold start
by comparing the engine coolant temperature to the ambient air
temperature during startup. The engine is considered cold when:
• Engine coolant temperature is below 122°F (50°C).
• Engine coolant and intake air temperatures are within 11°F (6°C) of
each other at startup.

Stage 2: Idle 2½ Minutes—Turn the air conditioning (A/C) and
headlights on to help the misfire monitor—the additional electrical loads
help even out combustion pulses. During this period, the O2S heater,
AIR, EVAP, misfire, and possibly fuel system (if operating in closed loop)
monitors run.

Stage 3: Accelerate—Prior to accelerating, turn off the A/C and
headlights (if possible). Open the throttle halfway until you reach
55 MPH (89 KPH). During acceleration, the misfire, fuel system, and
EVAP monitors run.

Stage 4: Steady State Cruise—During this portion of the cycle, the
O2S, AIR, EGR, EVAP, misfire, and fuel system monitors run.

Stage 5: Decelerate—Gradually coast down without applying the
brakes. Also, on manual transmission vehicles, remain in high gear and
do not press the clutch. During this period, the EGR, EVAP, and fuel
system monitors run.

Stage 6: Accelerate—Apply ¾ throttle until reaching 60 MPH (97 KPH).
During acceleration, the misfire, fuel system, and EVAP monitors run.
Stage 7: Steady State Cruise—During this period, the CAT, O2S, AIR,
EGR, EVAP, misfire, and fuel system monitors run.

Stage 7: Steady State Cruise—During this period, the CAT, O2S, AIR,
EGR, EVAP, misfire, and fuel system monitors run.

Stage 8: Decelerate—Gradually coast down without applying the
brakes. Also, on manual transmission vehicles, remain in high gear and
do not press the clutch. During this portion of the Drive Cycle, the EGR,
EVAP, and fuel system monitors run.

[abcxyzzz]

Anyone have a response to whether I can just step 7 to complete the Cat monitor test, or do I have to go in order from 1 to 8? Thanks.

[road_tripper]

I'm pretty sure all the tests are performed independently and there's no order.

With VCDS you can just choose each subsystem independently and run the test.

My 3.0's cats are on their way out; they take a looong time to fail (sometimes 100s of miles). If your cats are marginal, and they are the only emission component that is pending, you might need to do more 'steady state cruise' then you can imagine!

My state allows 1 emission subsystem to be 'pending', so I still can pass smog :)

EDIT:

this note:

"NOTE: If the CAT is marginal and the battery was disconnected prior to
the Drive Cycle, it may take up to five separate Drive Cycles in
order to determine the state of the CAT."

You might need to do do the step 7 several times, but you probably only need to let the car cool down a few hours before doing your next 5 minute drive at 55. Also pretty sure you can be going faster than 55, as there are no roads here in Las Vegas where you could drive 55 for 5 minutes and not be a road hazard or breaking the law

[Turbo510]

It could be bad O2 sensors. My '05 had CAT efficiency below threshold codes for a long time until I changed those sensors, and found all four to be originals, stamped 04. That was probably more than a year ago, and no such codes since, despite the CATs being that much older now, with 242K miles. The rear O2 sensors are comparatively accessible, the fronts were a challenge. I had the intake manifold off to deal with a coolant leak, and you could at least see them. And if all that work wasn't enough, the four sensors cost me somewhere around $400~$500.

[SJorge3442]

FWIW, I could NEVER get my 3.0 to go through the drive cycle in the 10+ times I've tried. Also echoing what others are saying about the o2 sensors. These could be failing/on their way out and causing the codes.

[abcxyzzz]

Thanks for the replies.
Yesterday I did get step 7 to complete, by driving 55 to 60mph for 5 mins or so, it's dangerous, all the cars are passing me on the freeway, I was trying to follow a truck. anyway, right when the monitor completed, the check light came on. sucks.

I don't know how to do o2 sensor repairs but that's pretty pricey to replace all 4. I guess a lot cheaper than replacing the cat. Perhaps by the sounds of it, i may only need to change one O2 sensor? I can do easy repairs, does anyone know which O2 sensor i would have to change? It's a 2004 A4 3.0L quattro avant.

I read something about spacers too, but you have to drill the metal to make it fit or something? anything i can just screw in without having to do drilling and such?

[DJHoro]

You can always get a tune. Idk how close smog stations look at that now but I've passed with bad cats and a tune before. Been years though and if u do decide to do the tune don't blame me if it doesn't pass inspection so ymmv. Also the tune would be a bandaid and I would suggest you eventually did fix the real problem or it can lead to other problems down the road.