Built4Sin

Popped a few suspension codes (02645 & 01577) over the last few weeks and doing some research I came to the conclusion it was my air compressor, running a bit weak in output (confirmed with VCDS).

Symptoms were after driving for a few minutes the yellow air suspension symbol would start flashing yellow (triggers when moving), followed by the TPMS light triggering and then staying lit. From there I would lose the ability to move the suspension anywhere but down from the current level. (Options gray out)

I then set the Q7 in in lift mode, set the tire change setting to lock the suspension and left it overnight. Next morning I checked to see if I had a low corner and thankfully it didn’t!

So it looked like I had an issue with the suspension maintaining pressure for its dynamic driving abilities. (Adjusting for road conditions)

First I changed the air compressor relay (4H0951252A), there is an new relay called for, that is built to better handle the voltage. It’s not too hard to reach, just remove the underside of the driver side dash and then the lower kneeboard. From there it’s in the upper right side, it’s a pain to reach one of the two clips that holds the relay tray in place, but it’s easy enough to accomplish with patience.

Unfortunately, no change.

Next step is the compressor. Just moving to AZ I don’t have access to my tools and all that Jazz, so I called up AZ Euros and had them change out the unit with a new one. The valve block connected to the air compressor was bench checked and found fine.

Bingo, good to go.

If you’re in Arizona I’d highly recommend these guys. They work with a lot of Q7s and do quality work. I also had them change out my Oil filter housing/ thermostat (059115389P), I found an intermittent code stored during VCDS scans during all of this about operating temperature not being met.

dreadlocks

This one is expected and normal, especially in high temps.. it will come back.. your other one tho indicates the valve block was having issues, your pump was likely fine.. Mine's been registering those faults since the day I bought it and I've never had any air suspension issues yet, knock on wood.. I usually trigger it a few times a summer and never in the winter.

here's the tsb on that fault:

Built4Sin

Correct, that code triggering is normal; especially if driving around in dynamic (which I do).

The valve block was checked and found fine (for now). At 125k miles, the pump was only outputting 10BAR, instead of the 12BAR (I believe it’s psi can’t remember the reading from VCDS off the top of my head). I have the old pump, figured I’d rebuild it for a spare.

I’ll update the thread if anything abnormal comes next.

emailpeter

Thanks for starting and contributing to this great thread. I do have similar issues with my 2013 Q7.
The overtemp error, I get this all the time, heard its normal, ignored it.

But the 02645 - Valves for Level Control System error, my mechanic says likely solenoid degrading.
After a week of not driving car, the yellow light comes on upon stepping brakes about 10 mins into driving.
After a few more days of vigourous driving in Auto mode, it goes off. Cycle repeats itself after a few weeks.

Q1-I don't think my relay is failing. Heard the 2013 models onwards have upgraded relay.
Q2-What is likely causing this yellow light / 02645 error ? Mechanic says could be the solenoid valve, but this thread seems to suggest compressor.

Let's keep sharing input, many others can learn from this common problem too.
Dreadlocks, you are one great guy, who helps lots of owners here. Kudos to your kind help and immense contributions.

dreadlocks

Q1: If you change the pump you must change the relay, most places wont warranty the pump if you dont also replace the relay.. If that relay fails its gonna surely kill the pump.
I figured if I ever need a new pump I'll buy it from FCPEuro and take advantage of their no hassle lifetime warranty since I plan on keeping this vehicle a very, very long time..

Q2: Valve Block is cheaper, might start with that and if no go then move onto the compressor.. its either the compressor or the valve block, but if I had to put a new compressor in I'd want a new valve block too since that covers most of the mechanics of the air suspension.

Built4Sin

150 mile update, the Q7 rides amazing. Better than I remember anytime in the last 45k miles of driving, the wife agrees. My guess is, the pump slowly dying, causes the suspension to be lazy and you just sort of get used to it, until it just can’t cope and codes start triggering. Dynamic used to feel like a low rider truck (built my first S10 lowrider in high school), now it’s just a perfectly firm sports car ride and not bouncy like it was previously. Auto feels like driving in comfort mode, but firm when needed (hence auto!), yet it never really felt like that prior.

Either way honestly feels like a new car, we’re both pretty shocked.

dreadlocks

What test did you do on the air suspension to measure its output?

Built4Sin

Go into level control 34, open the measuring blocks or advanced blocks (I think the basic setup looks cleaner) and watch valves, accumulator pressure and compressor pressure. Then go to output tests and activate the compressor. You’ll see your output.

emailpeter

Thanks to both Dreadlocks and Built4Sin for all input. Happy to hear you have solved it, while i get to learn from your experience.

Mine is still in good order, off and on clicking relay and compressor sound during driving, indicates all in still good order. Will lookout for constant relay on or excessive use, indicating compressor weakening, or some leak somewhere. I guess if the compressor is to be changed, best change the valve block and relay together at one go. Saves trouble/labour jacking up car to fix those again.

Q1. Threads never discuss air suspension degrading, they only speak of failure. Surely there is a gas absorber strut in there, does it degrade. Many only change the side where the rubber bag has burst or seals gone. Why not both sides at once ?

Q2. Here in my country, we have new units for air suspension, prices are coming down. Also some China made ones. Or whether some shops can recondition the original one with a kit. All input is welcome. We are all in this same boat, learning to prepare for eventualities.

Generally I find the Q7 rides a bit "floaty" in auto or comfort. Expected for air susp, and a huge heavy car that can bounce down (and up). For dynamic, the ride quality goes to bumpy and jarring for our bad local roads. But overall, it seems to be working well.

Built4Sin

1500 mile update, still perfect!

Did lose a tire Sunday night with a little night off-roading... 21’ DWS06 versus some sort of kryptonite rock, that punctured the side wall, just below the rim lip. I learned that a valuable lesson would be trying out the spare collapsible tire! Mine was filling up off center, of the rim. I ended up half filling it up, mounting it and driving a few circles, until it seated itself correctly, and then finished up the fill. Ended up getting the last DWS06 in Phoenix the following morning (essentially free with discount tire hazard certificates ($50 a tire)).

Awesome throwing the car into dynamic & lock for the change. Wish our Q7’s had the tire fill port connection, to use our onboard air compressor and tank, like the Touareg and Cayenne.