C1A18-64 (2E) "Pressure increases too rapid when filling reservoir - Algorithm based failure - signal plausibility"

Hey Guys, so I'm getting this error, intermittently. Not quite sure how to troubleshoot it. From the forums, looks like it's either the compressor or the central valve block?

Few notes:

- Sometimes shows up when I start up, every few days, sometimes doesnt show up for a month
- Doesnt seem to effect suspension performance, raising and lowering from road height to off-road to park, still work fine
- Havent tried raising to off-road and pulling fuse and leaving overnight
- Havent tried spray bottle and soapy water on suspension struts
- Have checked on-road height, on level surface, and all four corners are at proper height (no sag)

Secondly, there are no LR dealerships near me or mechanics that understand air suspensions (that I've found). I'm going to troubleshoot this myself, so any advice would be awesome. I'm ok with a wrench, not epic. I stay away from most things under the hood.
any advice would be awesome on how to properly troubleshoot this thing.

thanks in advance.

 

I had this happen. I checked the central valve block, and the wiring harness was loose! That is the first thing I'd check if I were you....

 

I think houm_wa is on the right track. Your center valve block could be trying to quit.

Here’s what the book says:

C1A18 - 64 Pressure Increase Too Rapid When Filling Reservoir

• Reservoir valve stuck closed
• Reservoir pipe blocked/damaged
• Reservoir port blocked/restricted
• Pressure sensor fault

Refer to the guided diagnostic routine for this code on the approved diagnostic system.

 

I did the overnight sag test last night.

I raised the rig to off-road height and took measurements from wheel well to floor and then pulled the fuse. And in the morning took measurements again, +/- 3% user error (measured first set at night fumbling measuring tape, cellphone light, note paper and pen :

Before / After
Front Driver: 87.2cm / 86.6cm
Front Passenger: 86cm / 85.3cm
Rear Driver: 89.8cm / 89.8cm
Rear Passenger: 89.8cm / 89.6cm

 

hey sorry I'm not sure what this means. Could you elaborate?

 

Not sure why your quote cut out the important part of my post.

The book is pointing to your center valve block, like houm mentioned. This block controls air into the reservoir. If your center block is stuck just intermittently, you’ll still air up the reservoir intermittently and not have a bad suspension problem. When the center block is stuck permanently, you’ll no longer get air into it.

The fact that you’re not losing height overnight confirms you’re leak tight and your front/rear blocks are good. It has nothing to do with your center.

You might easily confirm the bad center by unplugging it. You’ll gain a pressure sensor code, but your other code probably won’t change. Clear codes first, then unplug.

There are far better suspension experts on here than me, so please set us straight if I’ve misstated anything.