Thread: Air suspension wont vent

Look into why the compressor continues to run as the system certainly won't vent if the compressor is running.

Have you picked up an IID yet? You can watch what it all does in real time which will point to exactly what is going on.

The iid tool should arrive next week, the compressor keeps running because the car doesnt seem to know what height it should be in,it thinks it's on an obstacle then tries to raise, then I get the message that once clear of the obstruction reset suspension.
It seems related to the rear as i reckon the rear is continue to raise higher than the front . Hawkeye tells me RR has a totally different offset to the rest of the car but that has been like it before this issue. I removed the exhaust pipe from the compressor and when i drop to access height it vents no problem, but upon start up the car should vent then set its height , well that doesnt happen , the compressor starts and continues to run.
I'm not getting ride height faults, just the fail to vent fault. I actually dont think it's a compressor fault but I will change it just to see as I have a spare. I'm thinking it's a height sensor issue or maybe just a suspension reset as a start.
Cheers Bulletman

So I just started the car and dropped it to access height then got out and watched what happened, the car dropped then the rear started to pump up and the front stayed down , hence this keeps the compressor running, then I put it into normal height and it gives a warning on dash suspension raising slowly even tho the rear is close to normal height the front remains low.
Something is causing the rear to pump up so whether I have a blockage and it cant vent the rear or the rear valve block has an issue I am not sure

Cheers Bulletman

When you get the IID, on top of being able to watch it do its thing, you'll be able to manually activate each valve so you can test each element.
Without being able to read the complete fault codes and watch the variables you're kinda flying blind.

If the front is all the way down, and the back is all the way up it'll look like my brothers Prado after the GVM upgrade. At least you won't be flashing other drivers.

I can lock the suspension in access height the car will go down and then the rear will pump up for whatever reason even tho its supposed to be locked in access height.
The fact that the car doest vent makes me think it's related. I can get the car to what looks like normal height and pull the relay to stop the compressor so the car is drivable but it's not right. A new relay doesnt change things .
Cheers Bulletman

The first thing it does on fire up is try and adjust the height if required. It then closes front and rear valves and continues to run until the reservoir hits its setpoint. So if the rear valve block was jammed open, then it would continue to run while pushing the back of the car up. The compressor would stop on overheat prior to it reaching setpoint.

If it was stuck open, then the car would attempt to lower and it should lower to the correct height. It'll then try to top up the reservoir which will then push the back of the car all the way up.

Looking at the inside of the valves, I'd be surprised if they both jammed open. The easy way to test would be to put axle stands under the chassis and pull off one of the gallery lines from the center valve block (either front, back or compressor). If the rear valve is stuck it'll dump the back of the car on its arse as all the pressure will dump.

Thinking about it, easiest would be the high pressure line on the compressor that runs to the center valve block.

It sounds as though a rear height sensor is faulty, indicating that the corner is too low. In the absence of diagnostic equipment I would unplug the RR sensor connector expecting the system to use the remaining 3 height sensors, which it will do but without making fine adjustments.