Hello!

I have a problem with Audi Q7 2013 model.

Air suspension

When i start the car its no problem, suspension works fine, no codes. I can put it in all steps.

When start driving over 50 km/h TPMS light comes on and i get code 01772.

As long as the suspension works, if I change between comfort and dynamic when driving i get no code.

The code comes after it stays in correct level.

I have tried change the Block Valve for a new aftermarket but doesnt help.

The connector for Block Valve looks good.

Thanks if I can have som help with this.

 

And a big HELLO to you in Sweden! On this car you really need to have a VAG-compatible scantool to get anywhere. The Ross-Tech VCDS is the best for managing this car, as it can simply do a lot more than most other compatible diagnostic scantools. That said, here's where your code leads us:

Error code 01772 - Signal from Level Control Pressure Sensor (G291): Short-Circuit to Ground (GND)

From the Ross-Tech Wiki (Google search results):

Possible Causes

• Wiring issue between G291 sensor and J197 Control Module
• Faulty G291 sensor
• Faulty J197 Control Module
• Air leak in system

Possible Solutions

• Inspect and repair wiring harness
• Inspect for leaks with soapy water

Additional Notes

• When found in the VW Touareg, see Technical Bulletin V4305XX or the newer version of that: 43-05-02 | TPI 2010801
• When found in the following Audi vehicles check TSB 43-08-16 | TPI 2018765
  • https://static.nhtsa.gov/odi/tsbs/20...23920-9999.pdf NHTSA
    • 2006-2009 (4F) A6
    • 2013-2013 (4G) S6
    • 2013-2013 (4G) S7
    • 2004-2010 (4E) A8
    • 2011-2013 (4H) A8
    • 2007-2012 (4L) Q7
• May be stored in conjunction with 00453, 01583, 01770, 01772, 02645 and/or 02646.

 

One of the things you definitely want to do is replace the relay for the air compressor if you haven't already done so. They changed out the part# on the original to a more robust relay to keep it from failing in the on position, which then leads to compressor overheat cycling, and eventual failure of compressor. I just replaced the compressor and valve block along with the compressor relay on our '15 at 105k miles . Some of the symptoms of a worn-out and/or saturated dessicant media on a compressor is poor flow/poor performance/overheating constantly. You can see the trouble codes in the car if you have a VAG-compatible scantool for the overheating, etc. Basically if your will move between levels, but seems as though it takes a really, really long time to reach the next level up, then your compressor likely needs service or replacing. Multiple videos out there on how to diagnose and resolve issues with this air suspension.

Don't forget the simple stuff like the squirt bottle with water and dish soap mixed in to find any leaks (test static and with compressor running), but you really want to scan the car with the compatible VAG-type scantool if you are not already using one like OBD-Eleven, Ross Tech VCDS, etc. Otherwise you aren't seeing the full array of trouble codes the car has stored inside it.

 

I have a scantool that works good.

But the only code the comes upp is the 01772.

I have also tried with VCDS and its the same code.

The blockvalve is replaced.

The connector and wire to blockvalve looks fine.

The code come at the same time after start driving and come over 50.

I have try diffrerent metods when driving and if i let the compressor works all the time and change level it want come any code.

 

If i work with the button up and down like many times I will get the code 01577 also when try put in Lift position.

 

Important to realize the compressor is not able to run all the time regardless of it's age due to the heat build-up...it's air cooled, so your constantly changing the ride height multiple times is completely artificial...it'll heat up and it's cylinder temp sensor will shut it down. If the compressor is on it's way out, then the car will be very slow to change height settings, and to go all the way up to the top level, or Lift position places an extra strain on a compressor that could be getting weaker from a worn piston ring and water build-up in the dessicant beads/dryer unit attached to the pump, which blocks airflow and causes it to overheat quicker. I'd focus on that first error code that you are seeing pop all by itself.

Here's the Ross-Tech Wiki data on the compressor code BTW...it is not likely relevant as your actions were the cause of the shut-down/protective action, although you should look to see if this code is recurring (has other historical instances), or if the counter on it shows it has not been presented prior.

01577 - Turn-Off due to Over-Temp: Upper Limit Exceeded

Possible Symptoms

• Air Ride Suspension bleeds down

Possible Causes

• Air leak in Air Ride Suspension System

Possible Solutions

• Locate and repair air leak

Special Notes

• On vehicles with Air Ride Suspension, a leak in the system will cause the Air Compressor Motor to run too long and flag this code.

When I first encountered this code, it was from normal driving operation in the AUTO setting for ride height/suspension management. The car did not exhibit any corners dropping overnight, so the issue was isolated to the compressor itself going out. In replacing the compressor, I removed the air lines and then when reinstalled, pump ran great but the air lines didn't seal up tight, so the car drooped on one side after sitting for a bit. Replaced with new valve block with modern style push/pull connectors...issue solved. The relay was also replaced, as that is a known failure point and recommended service for air suspension cars. I list my experience with this shut-down from overheat sensed trouble code so you can see how it typically presents itself to the owner during normal operation of the vehicle.

 

So, the pressure sensor G291 is inside the valve-block: https://www.manualslib.com/manual/80...3.html?page=22
If you bought a knock-off valve block, you may be creating your own headaches, or just didn't resolve the issue.

Here's from another write-up of this issue, and I'd follow this one, as you may have overlooked checking the height sensors on the car, and the required re-leveling calibration you have to do on air suspension cars when replacing the height sensors or valve block, etc.

Special note :

When found in Audi Q7 or Audi A6,Before changing level control module pressure sensor G291. Check for the reading or all height level sensor. If found any fluctuations in level sensor then repair or replace them first. That will solve the problem . If it does not solve the problem then go for checking leak pipe, failure of level control module, or damage wiring harness of level control pressure sensor g291.

 

Must a calibration of the system be done after replace the block valve?

 

Audi, who made the car think so.....

 

Think so? Does that mean the it must be done otherwise I will have the code after replcement?