Suspension dump, CEL, VSC lights on! Help needed.

[RuffinIt]

I’m out on he trail and notice my LX470 is riding rougher than it should. I look down and the suspension has dropped to “Lo” and didn’t want to raise back to normal height.
Eventually, I was able to “get it up”, but it dropped back down periodically with the same hesitation on returning to normal ride height. After a few runs on this, the check engine light and the VSC Trac as well as the VSC off lights came on. ATRAC, however, would NOT come on when I went into low-range.
I’m at a loss. Any ideas or there?

Thank you in advance!

 

[Trunk Monkey]

Read the CEL code for starters.

 

[FxFormat]

Your accumulators (globes) are about to crap out on you. As for the truck not getting into Lo I have no clue.

 

[RuffinIt]

Sorry, I should have been more clear. It will go into low range, the suspension just keeps lowering itself.

 

[FxFormat]

How many miles do you have on the truck, the AHC system usually fails at 120K-150K, some fail before, some fail after but the majority of the failure rate is between those miles. Look under the truck to see if there's any leaks, check the AHC fluid to see if it's dirty, check the leveling sensors to make sure you didn't hit anything and damaged them.

 

[RuffinIt]

174,000. I replace the rear globes a while ago. It still rides well though. When my rears went out, it rode like a shopping cart. It doesn’t feel like the globes to me, but I could totally be wrong.
When my tears went out, I don’t recall any dash lights though. Do they typical go off when the globes go?

 

[FxFormat]

I didn't get any check engine light/VSC lights go on the dash when mine went out, it just rode like pogo stick. Have the OBDII scanned and see what's causing all those lights.

 

[PADDO]

Damper accumulators aka globes have nothing to do with dropping to Low or failing to maintain N height, nothing to do with CEL or dash lights either. You're getting BS AHC "alternate facts" here regarding globes so don't waste your time on this path.

 

[Julian Stead]

I just had this after a trip off road. Check for leaks. What is the fluid level like in the reservoir? I had a pipe go at the union, I thought it must be rust related but it wasn't, just age I suppose. Not sure if it is the same in the US but on my 98 land cruiser, the rear pipes where modified in 1999 to a larger diameter, so instead of just changing the pipe I had to change the shock absorber(RAM) as well as Toyota don't sell the older smaller diameter pipe anymore, not comfortable with having a imbalance of pipes on a single axle I changed the other side as well. So one split pipe became considerably more.

 

[RuffinIt]

I didn’t find any leaked. Fluid levels are where they were prior to the trip (250-300 miles). I’m thinking electrical. Is there a ground or a sensor connection that could throw all these issues?
I can’t find my code reader, so I don’t have them. I’ll post up again when I get them.
Strangely, all symptoms went away on the road trip home.

 

[RuffinIt]

Found my code reader. P505, but it seemed to be idiling ok. I found a post on club Lexus from someone who had the VSC and CEL both on and was able to fix the issue by cleaning wore connections.
The trail was pretty dusty and I was running tail gunner; I’m hoping it was just dirty connectors and some time with some cleaner will keep it from coming back.
I’ll update when I have time to spend doing it.

Thank you everyone for the suggestions and please let me know if there are any other ideas.

 

[Julian Stead]

To me it sounds like two seperate issues, I cant see why dropping to low would have any link to p505. Is your ahc light blinking? Check your battery voltage for a start just to confirm it is ok. How much weight are you carrying, that can cause your ahc to drop, also are you able to read your pressures in your AHC system, maybe it just needs a good service and bring back to spec. Check rear springs just incase one has snapped and also your torsion bars, make sure they look secure, also the front lower arms where the torsion bar attaches cracks so have a good look. It sounds like the system is overloaded to me, that is if you don't have any leaks.

 

[RuffinIt]

An overload is possible. I was wondering about that. It was packed for a camping trip with a stuffed cooler, three big guys and a big dogs on a rough track. It did clear out on the way home when two of the other guys were no longer in the vehicle.
Maybe it’s time to switch to OME?

 

[Julian Stead]

You might just need to crank your torsion bars and add spring spacers to the rear, there are loads of threads about this. It just depends on whether you want to keep The AHC. I would recommend new springs for the rear though as they are only very light duty and don't last that long.