Looking for recommendations.
We were on a group ride yesterday and the AHC system on my 13 LX decided to go into low height and not come out. Leaving the vehicle off for 5 minutes seemed to get the pump working again and it returned to normal height. Picture above is with the rig in normal height.
I purchased this truck in early spring 2020 with 112K miles. Truck was in fine shape but definitely wasn't babied - figured it was the perfect candidate for a New England overland style build. In the process of reading about these trucks on this forum I found that many folks saw great improvement with both an AHC fluid flush and globe replacement. Was able to do both before the Slees got installed and the ride was indeed much better.
Flash forward a month and I mounted a set of RW with 34" Ridge Grapplers. Naturally I wanted to see the truck in its highest suspension setting. Move the switch up and the rear raises first and then the front raises - cool. I get out of the vehicle to take a look and sure enough the front looks like it's in normal height and the rear looks like it's in high. Weird. So window open and door closed I cycle the system again this time using a broom handle from outside the truck so i can see it raise in real time. Sure enough the truck raises from N to H but once it reaches its max height in the front it dips back down to N height while the rear remains in the H setting. FWIW I did a sensor lift on the vehicle on the recommendation of many of you here. No errors on dash.
First place I look is the AHC tank (behind the RR fender liner for those who don't know) to see if there was fluid. It was low so I added some more and bled the system. No change. Couple of weeks later same issue going into High decided to bleed the system again, lots of air bubbles come out, then clean pink fluid - no change.
At this point my thought process is:
The truck stays in normal just fine and with the sensor lift there is no rubbing with the 34" Nittos. Combine that with the rad AL Dissent bumper and my approach angle is probably good enough for anything I'd do towing our trailer. This is an overlanding rig and not a crawler so let's file this one away for a later date and address the numerous other ongoing life fires.
Yesterday we got the entire family (2 Ridgebacks, one excited wife and 4yo little savage) loaded into to the truck for a group ride. Point man indicates over GMRS to engage 4LO when we get to the base of a gnarly uphill. 4LO engaged the LX starts to raise up to H and sure enough I see the front fall back to normal after it reached the peak. Whatever, I've got plenty of clearance and tire, I thought. Start making it uphill and I notice the vehicle is now indicating L height - WTF! Make it to the top and get out to take a look and see the truck is indeed in the low setting front and rear. Pressing the lever up doesn't do anything. So I let the vehicle sit for a few minutes with the engine off. Upon start up the vehicle gets back to Normal height setting. Rather than risk holding everyone up we decide to bail on the ride before getting to some more difficult sections which require 4LO. Get out to the trail head and notice the rig is in the Low height setting again, let the vehicle sit for a couple of minutes no change. Get the truck to the gas station to fuel and air up and let it sit for a while. Truck eventually returns to Normal height.
Once we get home I break out my Jolly Roger copy of techstream for the first time and connect the vehicle to try to see what's going on. Codes below are what showed up - notice nothing current and nothing pending. Only time I saw the AHC light on the dash was when I flushed the fluid and did the globes and it went away quickly so I'm wondering if those are the stored codes? The real kick in the balls is the software kept crashing when I attempted to run the various AHC tests - I guess you get what you pay for haha.
Where I'm at now:
As of writing this I am at somewhat of a loss of what to do. I am tempted to delete the system and install an OME, KING or ICON coilover kit and electrical tape the AHC warning light but I don't want to give up on the AHC just yet. On a whim I purchased an OEM pump module ($900) with the intention of installing it but I don't want to be in a position where I'm just throwing expensive parts at the truck and praying it works. The last thing I want to do is bring it to my local Lexus dealer as they never even touched the AHC system, even forgoing the recommended 60K flush. I do have a customer who is the GM of a Lexus dealership. Maybe he could lead me to the AHC guru if there is such a person? Does anyone know of an indy shop with experience working on AHC?