AHC Woes: 2013 LX (1 Viewer)

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Thanks @lx200inAR. I spent some time reading up on how to run Techstream on a Mac last night, and am going to dig into it this weekend. Between the Veepeak with the Toyota pack, as well as Techstream, I should be able to do just about anything I need to regarding both diagnostics and modifying different settings. I trust that Techstream is what the Lexus and Toyota technicians are using.

Regarding the AVS, my theory is that I simply don't have any power to the pump due to a wiring issue, at a minimum. The LX is in N mode currently. If there was a puncture in the system or leak of any kind, I wouldn't have enough pressure for the truck to stay in N mode, and would rather drop to Low and stay there due to lack of pressure in the system and the inability to to re-pressurize to raise again. Do I have this right?

Off to the dealer soon. For some strange reason, I feel better about the possibility of a rodent chewed wire that is causing this problem rather than something else like another failed pump. Fingers crossed.

Thanks all for the helpful responses!
 
I spent some time reading up on how to run Techstream on a Mac last night, and am going to dig into it this weekend. Between the Veepeak with the Toyota pack, as well as Techstream, I should be able to do just about anything I need to regarding both diagnostics and modifying different settings. I trust that Techstream is what the Lexus and Toyota technicians are using.
I've run Techstream on Macbooks both in Bootcamp and in Virtual machines. I use a VXDiag dongle to connect it to the OBD2 port on the 200. You can do pretty much anything you might need with it, and many things that other apps can't.

Yes, Techstream/TIS is what the dealer techs use.

I have OBD Fusion with the Toyota packs and an ELM 327 Wifi dongle, but haven't used it much. I've seen a bunch of people on here use it for monitoring dashboards. I'm sure it will come in handy someday...
 
Thanks @lx200inAR. I spent some time reading up on how to run Techstream on a Mac last night, and am going to dig into it this weekend. Between the Veepeak with the Toyota pack, as well as Techstream, I should be able to do just about anything I need to regarding both diagnostics and modifying different settings. I trust that Techstream is what the Lexus and Toyota technicians are using.

Regarding the AVS, my theory is that I simply don't have any power to the pump due to a wiring issue, at a minimum. The LX is in N mode currently. If there was a puncture in the system or leak of any kind, I wouldn't have enough pressure for the truck to stay in N mode, and would rather drop to Low and stay there due to lack of pressure in the system and the inability to to re-pressurize to raise again. Do I have this right?

Off to the dealer soon. For some strange reason, I feel better about the possibility of a rodent chewed wire that is causing this problem rather than something else like another failed pump. Fingers crossed.

Thanks all for the helpful responses!
So AVS doesn't really require the pump. It's basically a solenoid that allows 16 steps of different valving at the assembly near the globes (x4 one for each wheel). But there have been cases where there was a DTC triggered by a malfunctioning valve actuator that caused the system to basically stop doing any modulation.

As far as "if there was a leak". Your statement is only half right. You could have a leak anywhere between the pump reservoir (behind RR wheel) and the leveling valve (mounted to frame in front of LR wheel) and the system would remain pressurized. In fact, the most common leak that occurs is from the tube that runs over the axle near the muffler. I'm not saying i think you have a leak, just saying it's still possible even though the system is holding pressure. You're correct in that as long as nothing happens to release pressure, you should be able to drive at normal height fine. The only reason i mentioned AVS before, is that could be the reason for the rough ride, otherwise, there should be no difference.

This post in this thread has a link to the OBD Fusion dashboards i use. One of them is an AHC monitoring dashboard. I never do any maintenance on my AHC system without having either this or techstream monitoring activity.
 
I suppose I could do that. My only fear about rat poison is that they usually go someplace and die and the corpse rots someplace that you can’t find them. That’s why I went with traps baited with peanut butter.

Definitely do not use poison on wood rats/tree rats. Irish Spring can work, but you need to shave it into small slivers and keep it in a mesh bag. You can also use moth balls but they are very caustic so don't drive with them in the truck or engine bay. You should also get some peppermint spray and spray everything once a week or so. You can buy commercial versions on Amazon. These aren't foolproof because some rats and mice are not as sensitive to it, but it does help.

The best option is to set a trap under your hood every night with some peanut butter and sunflower seeds. If a wood rat is around, it will go for that first every time. Also, I open my hood during the day and start the truck every day, and drive it at least once or twice a week.

But traps are the best option.
 
@1world1love thanks for the intel. I’m at the dealership now. Set traps under the truck in the driveway last night and found two empty (but still set) traps this morning.

I really like the trap under the hood with peanut butter and sunflower seeds idea.
 
I had 4 different Lexus dealerships refuse to do the flush, the one technician I spoke with who had been working at Lexus for 18 years told unless it’s broken don’t mess the system. He checked the fluid it was perfect and that was that.
 
I had 4 different Lexus dealerships refuse to do the flush, the one technician I spoke with who had been working at Lexus for 18 years told unless it’s broken don’t mess the system. He checked the fluid it was perfect and that was that.
Yikes!

When my issues are all said and done, I'm going to drop the spare tire, pull the access panel, and check things out in greater detail (when it warms up here, that is), including inspecting the AHC fluid. I'm really intrigued by this system after spending what feels like 100 or more hours researching it here on Mud.

Considering every fluid in our trucks breaks down over time, I figure it's only a matter of time before not doing a flush is going to cause a problem IMHO. I think this is why so many of us baseline our vehicles when we buy them used, because we never know when the last time any fluid was changed, or if it was done correctly. I've also seen photos of really nasty black hydraulic fluid that looked more like motor oil come out of some members' trucks. And I believe that the AHC fluid is pink when it's brand new!

YMMV, but after seeing the price tag of a new pump, globes, etc, I'd rather go the preventative maintenance route and sleep better at night. Just gotta find someone 100% qualified that you trust to do it if you aren't going to do it yourself.
 
Yikes!

When my issues are all said and done, I'm going to drop the spare tire, pull the access panel, and check things out in greater detail (when it warms up here, that is), including inspecting the AHC fluid. I'm really intrigued by this system after spending what feels like 100 or more hours researching it here on Mud.

Considering every fluid in our trucks breaks down over time, I figure it's only a matter of time before not doing a flush is going to cause a problem IMHO. I think this is why so many of us baseline our vehicles when we buy them used, because we never know when the last time any fluid was changed, or if it was done correctly. I've also seen photos of really nasty black hydraulic fluid that looked more like motor oil come out of some members' trucks. And I believe that the AHC fluid is pink when it's brand new!

YMMV, but after seeing the price tag of a new pump, globes, etc, I'd rather go the preventative maintenance route and sleep better at night. Just gotta find someone 100% qualified that you trust to do it if you aren't going to do it yourself.
If you have time and can make the trip down Lexus of Colorado Springs can do it.
 
Update:

Just heard from the dealership. They say I need a new harness that goes to the AHC pump. Apparently this harness is corroded.

Is it possible to save this harness, or do I need to proceed with the repair?

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Just off the phone with the service manager. The shop foreman was assigned the task of figuring out what the issue is. He apparently will clean corrosion when he can, but says he cannot this time. The part (I don't have the part #) is $309 and change.

I'm inclined to give them the go ahead to order the part and do the work, and move on with my life, unless somebody on the forum has done this and it's a 1 banana job.
 
If you could get the right pins it's possible you could repin that plug, but i'd be worried about the plug being water tight if it's got that much corrosion. Surely with an FSM you could attempt to find new plugs as well and repair it all. Wonder if they actually tested across the connector. That would make sense as to why you were having no issues sometimes and failures other times. Corrosion like that can do weird things with electron flow.

If it was me,

I think those pins get pretty brittle once they get corroded, but if they seemed solid, i'd try to clean up what's there and avoid any water crossings.
Or, if not salvageable, i'd have a temporary jumper with some aftermarket water-tight connectors bypass that connector and then in either case work on finding an OEM replacement connector and pins.
 
How much labor is in the quote? It can be done cheaper diy but a few $hundreds may not be a big deal over the entire length of ownership to do it right.
 
I'd probably attempt to clean it up using electric parts cleaner, a toothbrush, and then coat with dielectric grease. If that works, I'd source part from the cheapest spot I could, in case it happens again, and replace it myself at that point. Either way, $300 is not a huge deal, compared to a new pump. Electric corrosion like this can creep inside the cables, so long term, a wiring harness replacement may be the best bet.

Wishing you a happy resolution to the situation.
 
Thanks everyone. I went ahead and gave the dealership the go-ahead to order the part and do the work. I really appreciate everyone chiming in on this, and hopefully this thread helps someone else in the future should they experience what I have.

I'll start a build thread when my build fund is replenished :)
 
Yikes!

When my issues are all said and done, I'm going to drop the spare tire, pull the access panel, and check things out in greater detail (when it warms up here, that is), including inspecting the AHC fluid. I'm really intrigued by this system after spending what feels like 100 or more hours researching it here on Mud.

Considering every fluid in our trucks breaks down over time, I figure it's only a matter of time before not doing a flush is going to cause a problem IMHO. I think this is why so many of us baseline our vehicles when we buy them used, because we never know when the last time any fluid was changed, or if it was done correctly. I've also seen photos of really nasty black hydraulic fluid that looked more like motor oil come out of some members' trucks. And I believe that the AHC fluid is pink when it's brand new!

YMMV, but after seeing the price tag of a new pump, globes, etc, I'd rather go the preventative maintenance route and sleep better at night. Just gotta find someone 100% qualified that you trust to do it if you aren't going to do it yourself.
I could be wrong, but. In the years 2016 and forward didnt they take the fluid flush off the required maintenance schedule?
 
I could be wrong, but. In the years 2016 and forward didnt they take the fluid flush off the required maintenance schedule?
I'm not sure. I've got a 2013. Maybe someone with a 2016+ with knowledge of the maintenance schedule will chime in.
 
Update:

I got the ScanGuage II out of my 80 series and plugged it into the LX. It said there are no codes. Seems crazy considering there is an AHC warning on the dash.

So I ran to the local auto parts store, thinking maybe my old ScanGuage II couldn't read from a newer vehicle. The guy plugged in his scanner, and same result... no codes.

My bet is that this rodent got back in there and chewed something else. I put a bar of Irish Spring under the hood as a deterrent the other day, and I also set two more rat traps and put them under the LX just now.

I did kill a tree rat in a trap in my driveway two nights after I took the LX in to get the wiring harness replaced last time...

Who knows, maybe the rat I killed isn't the rat bastard who did the damage last time around.

Besides a bar of Irish Spring under the hood (I was advised to do this by the Lexus dealership), and setting traps of course, does anybody have any sage advice to keeping rodents away from my truck? Unfortunately, I do NOT have a garage to park it in. I also don't want to put poison out as there are some free roaming neighbor cats in the neighborhood, and I would hate to inadvertently kill one of them (although they certainly aren't doing their job very well at the moment).
A rat or squirrel got in my 21 LC and ate some wires causing it to go into limp mode. Cold night and warm engine are not a good combination--$50 harness portion and 5 hours labor. Put large and small kill traps and one Havahart live trap. I live in congested suburbs so I can't shoot the buggers. Gonna be in big trouble when may Ferrari gets back if these insulation eaters aren't gone.
 
I'm not sure. I've got a 2013. Maybe someone with a 2016+ with knowledge of the maintenance schedule will chime in.
Just up the way from you in Niwot, CO. I have a 2017 lx570 and the maintenance manual shows 60k ach flush. Just had my 60k done at Stevinson of Lexus in Fredrick. After seeing some of the pricing for service, pleasantly surprised on the cost.
 

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