RTH: AHC system just let go (out of the blue) (3 Viewers)
- Thread starter arbetrader
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- Thread starter
- #22
Thanks for the info. I believe the bad batch had come out in 2021 and was limited to about a year or a bit less. I ordered mine directly from the Toyota stealership in Washington state, and they ordered it from their central warehouse, I did ask them about that but they said it was newer stuff... Not sure??
It came out of the Japanese (kind of cool looking) 2.5L tins. I still have some leftover.
In any case, If replacing I'll be sure to use fresh (new) anyway. Thx for the input. I'll likely find out on Wednesday during the diag by the shop.
Who would ever think an unwashed 2009 LX had anything to do with my self worth? It’s a car my man. It’s no better than any other way to get from A to Z. Worse than some, better than others. I could have cared less which brand of 200 I bought. Didn’t care 6 years ago, and don’t care now. Don’t care what brand you bought either.
Car companies create brands to separate you from your money. They market the brands to different kinds of people. Since I bought mine used, I wasn’t marketed too. I just bought it from the guy who bought from the guy who got marketed to, and could afford to buy an $84000 car at the height of the Great Recession. Maybe that person cared that it was a Lexus.
I’m not sure if the pump plug is behind the fender fascia, I don’t have that fascia on anymore so I can see mine, . It is tight against the passenger rear inside rail, near to the trailer plug breakout. it is possible to jumper the pump with 12v directly. So you could try that. My pump has stopped working twice, both associated to that plug being a tad loose, once after a short term body lift, and once a year or so later for no reason. Both times simply making sure it was firmly seated restored function. I don’t think this is your roost cause though.
There are threads on here to get the FsM, so then you can find the plug pin out.
Another potential culprit is the AHC computer. Do you see the AhC section in the MID (the H normal L diagram)? That goes away when the AHc computer is MiA.
Have you checked the ahc fuses?
(Edit - don’t buy more globes, that is almost certainly not the issue)
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- Thread starter
- #26
What do you mean whether or not I see the AhC section in the MID (H normal L)? Are you asking whether or not I can see the AHC status in the driver's side display? Not sure that MID means (perhaps multi display or something?) I will check again, I'm pretty sure it just says "Check AHC system", and the icon shows it in Low mode. Are you saying that if that icon doesn't snow up, then it might be the AHC computer instead of the pump?
This is exactly what happened when my pump failed, there could be an ECU issue as well. Have you hooked up techstream and tried to reset the error?
Yes, if the Ahc portion of the driver display in the speedometer disappears that is a sign the Ahc ecu isn’t getting power or a fuse is blown for the ecu. Seems like since you have Ahc display that is not the case.
All sign point to a non working lump, either mechanical or electrical.
I’d suggest trying to get power to the pump, either by hardwiring at the plug or forcing it on via a obd2 dongle or tech stream. This can rule out mechanical failure, or rule it in.
I’d be hard pressed to think of someone who has contributed more to the understanding of this platform and freely shares that understanding on this forum than @grinchy. He’s also a pretty great person IRL. In fact I bet if we all met we’d get along great.
Not sure why this discussion went so sideways. The internet is a strange place.
The back-and-forth forum boy bitching is helping nothing at all.
Check if you are getting power to the pump.
Check all your wiring and fuse, check for rodent damage.
If you have power to the connector at the pump then you can use a 12V lead acid or 12V Milwaukee/tool battery (what I typically use at work) to apply power to the pump directly. It draws a fair bit of current, so just power it for a second or two to confirm whether it’s working or not.
Report back with your findings.
If the pump is deemed to have failed, replace it. Removing the pump/reservoir assembly is simple. There’s a single hard line (like a brake line), the electrical pigtail, and some fasteners.
Install a new pump. Fill the reservoir and bleed the system per TIS. You’ll need Techstream/GTS+ and a couple of cans of AHC fluid. And a full bottle of patience.
Check if you are getting power to the pump.
Check all your wiring and fuse, check for rodent damage.
If you have power to the connector at the pump then you can use a 12V lead acid or 12V Milwaukee/tool battery (what I typically use at work) to apply power to the pump directly. It draws a fair bit of current, so just power it for a second or two to confirm whether it’s working or not.
Report back with your findings.
If the pump is deemed to have failed, replace it. Removing the pump/reservoir assembly is simple. There’s a single hard line (like a brake line), the electrical pigtail, and some fasteners.
Install a new pump. Fill the reservoir and bleed the system per TIS. You’ll need Techstream/GTS+ and a couple of cans of AHC fluid. And a full bottle of patience.
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How much additional weight is on your LX570? Are you sensor lifted?
- Thread starter
- #33
Nope, not sensor lifted, nor do we put too much weight into it. Don't tow heavy either (have a diesel 1 ton for that job).
- Thread starter
- #34
UPDATE:
Took it to a local shop with good reputation that works on alot of Toyotas, because there's no lexus dealer within an hour drive. But they don't have Techstream, and neither do I. They spent 3 hours diagnosing, and didn't come up with a whole lot. They disconnected the wiring to the pump and added manual 12v power to it, and did hear it whir a bit, but it wouldn't properly auto-level. At one point, the mechanic did note that it did finally raise back up, (when it was up on the lift) but quickly came back down.
So, I now have to drive it (on the bump stops) out to Lexus in Vancouver tomorrow, so they can diagnose once again... Should just have done this as the first step. Live and learn. They lexus tech that I spoke to this morning is suspecting the pump, after I informed him the symptoms (and their stages), and error codes on the dash. Will confirm tomorrow.
The mechanic yesterday that looked at it also found a pesky coolant leak coming from the rear heater. Does anyone know if this is a common spot? he said it was in behind the paneling behind the third row seat. Photo for reference:
Took it to a local shop with good reputation that works on alot of Toyotas, because there's no lexus dealer within an hour drive. But they don't have Techstream, and neither do I. They spent 3 hours diagnosing, and didn't come up with a whole lot. They disconnected the wiring to the pump and added manual 12v power to it, and did hear it whir a bit, but it wouldn't properly auto-level. At one point, the mechanic did note that it did finally raise back up, (when it was up on the lift) but quickly came back down.
So, I now have to drive it (on the bump stops) out to Lexus in Vancouver tomorrow, so they can diagnose once again... Should just have done this as the first step. Live and learn. They lexus tech that I spoke to this morning is suspecting the pump, after I informed him the symptoms (and their stages), and error codes on the dash. Will confirm tomorrow.
The mechanic yesterday that looked at it also found a pesky coolant leak coming from the rear heater. Does anyone know if this is a common spot? he said it was in behind the paneling behind the third row seat. Photo for reference:
I'm really surprised how hard of a time you are having finding someone with techstream. You can get a questionably legal copy going on a VM in like 5 minutes with a cable you can buy on amazon:
forum.ih8mud.com
I'm using this on a VM on a macbook air and it works fine
How-To: TechStream In 5 Minutes
I've been searching for a solution else where for a week, found solution here on 1st page. I really appreciate getco for his brilliant idea to containerise the package in a virtual machine and sharing here. I just wanna share my set-up experience. Installed the VM and XP image with TS given on...
forum.ih8mud.com
I'm using this on a VM on a macbook air and it works fine
- Thread starter
- #36
I heard it was easy to download, but I searched a few threads previously and it sounded a fair bit technical to get it setup etc... Which for me is a bit over my head. I also don't have a reader atm. Anyway I'd rather someone that actually knows what they're doing look at it. (which isn't really me).I'm really surprised how hard of a time you are having finding someone with techstream. You can get a questionably legal copy going on a VM in like 5 minutes with a cable you can buy on amazon:
How-To: TechStream In 5 Minutes
I've been searching for a solution else where for a week, found solution here on 1st page. I really appreciate getco for his brilliant idea to containerise the package in a virtual machine and sharing here. I just wanna share my set-up experience. Installed the VM and XP image with TS given on...
I'm using this on a VM on a macbook air and it works fine
One question I have is, how bad is it on the bump stops to drive around for a bit like this? I have to drive 80kms (flat highway) one way (160km return if not fixed) the way it is. It's not a bad ride at all just smooth highway, but when you hit bumps then for sure you feel it more. Will it do significantly more damage if I do this? Is it worth the extra significant cost to tow it in? (it's a hefty bill to do that, so want to know for sure first)
you're fine to drive on the springs.
- Thread starter
- #38
UPDATE:
I'm writing this update, just in case anyone else has a similar issue - and for future cataloguing reasons.
Basically what happened was that the AHC system went out (it was on the AHC low/easy exit setting) and wouldn't rise upon starting in early December 2024.
After several attempts to diagnose, and my initial inclination, it was suspected (by the dealer and myself) that the pump went out.
The old pump WAS still working, but it was weak, it wasn't strong enough to fully lift the vehicle. What ended up happening is that after installing the new AHC pump, the dealer found a pinhole leak in one of the lines, that started spraying AHC fluid out as soon as the new (and much stronger) pump was installed. The dealer installed several new lines (at least 2 or 3) due to corrosion (I live in Canada). Likely the old pump was working so hard it caused it to go out (given the pre-existing small pinhole leak).
Anyway, fast forward a few weeks after waiting for parts/availability etc - the system is running Oh so smooth now. Holy Cow, what a difference, it's so much smoother than when I even purchased it 2.5yrs ago. Man.
Anyway, it was expensive, but totally worth it. I will likely coat all the lines annually with fluid film or something like that just to protect it.
There was much back/forth and a few times ordering new parts etc, so the dealer (Regency Lexus Vancouver, BC) cut their repair hours in half which was a MASSIVE help. It lowered the cost substantially. I ordered the part myself from Japan and saved thousands too. So the total fix was likely less than replacing with a Dobinsons kit.
Man it drives so smooth now. And to have future AHC use for the stuff we use it for is a huge bonus. I'm floored at how nice it rides and am tickled pink how it turned out in the end.
That's it.
I'm writing this update, just in case anyone else has a similar issue - and for future cataloguing reasons.
Basically what happened was that the AHC system went out (it was on the AHC low/easy exit setting) and wouldn't rise upon starting in early December 2024.
After several attempts to diagnose, and my initial inclination, it was suspected (by the dealer and myself) that the pump went out.
The old pump WAS still working, but it was weak, it wasn't strong enough to fully lift the vehicle. What ended up happening is that after installing the new AHC pump, the dealer found a pinhole leak in one of the lines, that started spraying AHC fluid out as soon as the new (and much stronger) pump was installed. The dealer installed several new lines (at least 2 or 3) due to corrosion (I live in Canada). Likely the old pump was working so hard it caused it to go out (given the pre-existing small pinhole leak).
Anyway, fast forward a few weeks after waiting for parts/availability etc - the system is running Oh so smooth now. Holy Cow, what a difference, it's so much smoother than when I even purchased it 2.5yrs ago. Man.
Anyway, it was expensive, but totally worth it. I will likely coat all the lines annually with fluid film or something like that just to protect it.
There was much back/forth and a few times ordering new parts etc, so the dealer (Regency Lexus Vancouver, BC) cut their repair hours in half which was a MASSIVE help. It lowered the cost substantially. I ordered the part myself from Japan and saved thousands too. So the total fix was likely less than replacing with a Dobinsons kit.
Man it drives so smooth now. And to have future AHC use for the stuff we use it for is a huge bonus. I'm floored at how nice it rides and am tickled pink how it turned out in the end.
That's it.
How was your impression of Regency Lexus Vancouver? Did you get to talk with the tech that worked on your car, and do they seem knowledgeable and experienced with the AHC system? Or was this their first project with the AHC system? Sry for all the questions, I'm asking because I'm looking for a reliable place in the Lower Mainland to service my AHC system too. There aren't that many 200 series around our area.
Also, I'm assuming the labour bill is still in the thousands even after they cut their hours in half? Pls don't feel obligated to share if you don't want too!
- Thread starter
- #40
Regency went out of their way to really help me, likely just for my circumstance given there was much corrosion and the job started ballooning far beyond what they had quoted me. They even provided a free loaner car for a few days (2025 NX). Yes, it cost well into the thousands, but that being said most of the lines are all new (at least all the rear lines) - I might look into the front lines and new globes in 4 years time when the next fluid flush will be due.
Their service was excellent. I can't say enough good about it. The young mechanic that worked on it seemed pretty well versed in this. I had some reservations much like you at the beginning, but not anymore.
By the way, one of the service advisors (I believe it's David - I hope it's okay mentioning his name, he's a board member here too) understands these systems well because he has an LX470, built-out super nice as an adventure rig. He said that their dealership does these LX570 pumps quite often, a few every month from what I recall him saying. He said for some reason they seem to go out on them more than even the LX470s, my hunch is the rearward location making them subject to more corrosion as they age. The 470's reservoir/pump is under the hood which is a better location.
I wouldn't hesitate to take it there again in the future. They'll be doing any AHC work for me in the future but hopefully it won't be necessary.
