Vehicle: 2010 Landrover LR4

Fault: Air Suspension Fault (Code U0421-68)

Description of Issue: I drove my landrover for over an hour yesterday without issue on the freeway. I noticed an "air suspension fault" on the screen when I got closer to home. I parked my vehicle and noticed that the rear suspension was lower than the front. I checked the 4x4 screen, which indicated that the rear tires were lower, and validated what I was seeing. I tried to raise and lower the suspension, but nothing would happen ( I am assuming because the air suspension fault is active, will not let it raise/lower?). I let it sit overnight and turned it on in the morning, drove it around, and still has the same issue--Rear of the vehicle seems to be at bump stops and super bumpy ride. It will not raise/lower and the "air suspension fault" comes on as soon as I start the vehicle. I do not hear the compressor at all turning on or off.

Current Diagnosis and corrective actions taken: I've been reading through these posts as I am the new owner of a used Landrover and am happy to be part of the group!

I went to AutoZone and they told me the specific error showing is U0421-68 (invalid data received from ride level control module) I checked the Rear Valve Block and found that the power was disconnected (see picture). I reconnected it and turned on the vehicle. I heard the compressor turn on (finally!) and I heard a short burst of hissing every minute or so. The screen asked me to select height. When I try to select the height, the "air suspension fault" comes back on. The rear is still sitting very low (bump stops) and will not inflate. The front looks good. Every time I turn on the vehicle now, the screen asks me to select the height, and when I do, it goes straight to "air suspension fault".

Any suggestions on what to do next? Your expertise would be appreciated! I have images for you to see what I am dealing with. : )

low rider : )

too close for comfort.

unplugged rear valve block

 

Try jacking the rear up first. you may have gotten your ride height sensors out of range. I have heard of this happening as others have gone through something similar.

 

Thanks Jeffh. Yesterday, I tried checking the rear valve block connection again and zip-tied it this time. I started the vehicle, moved it forward and back in the driveway and then I heard the compressor turn on and the back end raised. No more fault!.

Next issue found: What I found was a consistent air hissing on the back left side of the vehicle. I sprayed with water and soap next to see if it was the airbag (it wasn't!). I sprayed the rear valve block and bubbles started forming. It was down back on blocks within 5 minutes! My next step is to check the tightness of connections on rear valve block, but I am thinking it will need to get a new rear valve block since it is original(~$150 US).

 

i had this happen with the front block once upon a time. i found it unplugged so plugged it back in. suspension started to rise then it blew the plug off again. there was an internal pressure fault in the block that was causing pressure to bleed into the electronic section and blow the plug out. replaced the block and all was good

 

ugmw177--Great feedback! I appreciate it.

 

I replaced the Rear valve block and it is working like a charm. No air hissing or leaks. Thanks for the input.