Disabling the AHC and AVS systems, no warning lights.

[paulunm]

So I went a head a disabled AHC on my 09 today, Here is what I did:

Here's a brief rundown of the steps I followed:

1. Disconnected the battery.
2. Pulled the AHC relay.
3. Pulled two AHC fuses on the passenger side.
4. Disconnected the two bottom cables from the AHC module behind the backseat cover and left the top one.
5. Reconnected the battery.

Everything seems to be functioning well with no errors on the dashboard. The AFS button appears to be operational, so I assume it's still functioning as intended.

Upon reading through this thread, I read that some members reinstalled the relay after disconnecting the AHC module. I'm curious to know if there's a specific reason for this and if I should also reinstall the relay in my LX.

Bonus Pic


View attachment 3461290

What’s the verdict on the ride?

 

[propernorf]

What’s the verdict on the ride?

Pretty solid and really good to me. The AHC system was in bad shape when I got the truck and needed lots of work so anything would've been an upgrade.

 

[orthopod]

What’s the verdict on the ride?

Does anyone have a picture of the of the ahc module and the exact cables to disconnect

 

[propernorf]

Does anyone have a picture of the of the ahc module and the exact cables to disconnect

Here is bad picture of the module, disconnected the other clip at the bottom both blue.

 

[AJLaz]

I’m in the midst of ahc delete and at the best part, the rear shock mounts. I cut down an offset wrench and am able to get it to grab nicely, unfortunately it appears the nut is just about completely seized. If I had it my way if change the forum name to ih8rust.
My plan B is to cut off the old strut entirely, any recommendations on an incision point? Given the clearance on top I figure I’ll remove the bottom bushing and cut through there, but it will still be pretty tight.

 

[jbyrd78]

I’m in the midst of ahc delete and at the best part, the rear shock mounts. I cut down an offset wrench and am able to get it to grab nicely, unfortunately it appears the nut is just about completely seized. If I had it my way if change the forum name to ih8rust.
My plan B is to cut off the old strut entirely, any recommendations on an incision point? Given the clearance on top I figure I’ll remove the bottom bushing and cut through there, but it will still be pretty tight

I ran into a similar situation when I swapped the shocks on my 2011 L.C. The top nuts on the shocks were seized on, and I had to cut them off with a sawzall. The best access you are going to get is from the wheel well with the tire off. You may also have to cut the top that goes from the AHC line to the shock off as well in order to have enough room to install the new shocks. Keep up posted.

 

[AJLaz]

I ran into a similar situation when I swapped the shocks on my 2011 L.C. The top nuts on the shocks were seized on, and I had to cut them off with a sawzall. The best access you are going to get is from the wheel well with the tire off. You may also have to cut the top that goes from the AHC line to the shock off as well in order to have enough room to install the new shocks. Keep up posted.

Good call I ended up cutting the top Mount off with a 9” metal sawzall blade. I was able to get the rusted bolts to the ahc line out with an easy out socket so that part wasn’t an issue. I’m 3/4 way done with the ahc delete, I’ll post a short write up on tools and parts I used when complete.

 

[agathos]

Back from the dead and enjoying catching up on what everyone has been doing with the 200 series, AHC, and alternative suspension options!

Just a quick question for anyone in general, but wondering if @turbo8 , @1UZJ80N60 , @TeCKis300 or anyone else have seen someone successfully delete, or at least temporarily disable, AHC on a 2016+ LX570.

I may or many not have ordered some long travel coilers for a non-AHC equipped LC200 that ended up having more rust than I want to deal with. In lieu of said rusty LC, I may have found a 2017 LX570 that would look lovely on said long travel set-up with coilovers, however, it would be nice to run those without a warning light on the dash.

Hi,

I'm in process of building a 2016+ LX570 with 6.0L stroker kit (BC) and Harrop TVS2650 supercharger. Shocks are removed and replaced with King Off-road racing suspension from filthy motorsports - one thing I found out is that the headlights beam leveling piggyback on the AHC control unit's height sensor via lin-bus system to automatically level the beam - if you remove the AHC ECU you will get headlights system error message in the dash - if you plug in the AHC ECU with the relay pulled off, you will have the AHC error message pop-up in the dash. I'm in a bit of predicament so if there is anyone successful in removing the AHC ECU off the 2016+ MY please shed a light on it

 

[tbisaacs]

Hi,

I'm in process of building a 2016+ LX570 with 6.0L stroker kit (BC) and Harrop TVS2650 supercharger. Shocks are removed and replaced with King Off-road racing suspension from filthy motorsports - one thing I found out is that the headlights beam leveling piggyback on the AHC control unit's height sensor via lin-bus system to automatically level the beam - if you remove the AHC ECU you will get headlights system error message in the dash - if you plug in the AHC ECU with the relay pulled off, you will have the AHC error message pop-up in the dash. I'm in a bit of predicament so if there is anyone successful in removing the AHC ECU off the 2016+ MY please shed a light on it

View attachment 3474425

can't wait to see more. It might be different with 2016+ but folks have kept AFS by keeping the height control sensor on the UCAs. Have you tried that? Sorry if I missed it.

 

[agathos]

can't wait to see more. It might be different with 2016+ but folks have kept AFS by keeping the height control sensor on the UCAs. Have you tried that? Sorry if I missed it.

Interestingly the 2016 does not have an AFS fuse, and the height sensors are also wired in the control unit through 2 sockets as opposed to 1. The ECU communicates the height sensor to other control units via can-bus network, including the headlight leveling system. so the choice right now that can figure out is that:

1. unplug AHC and have the headlight error pop-up in the dash with beam leveling not working; or
2. plug the AHC and have the beam leveling work-ish but have an error for AHC pop-up

I'll do some more experiment and share it here.

here is the screenshot of the headlights control unit system RH and LH

here is the screen shot of the AHC system socket and sensor pin-out

the 200 on the Left is a supercharged 2UZ-FE and on the Right is 6.0L supercharged LX570 2016 MY

 

[AJLaz]

Appreciate the responses. In an attempt to put all these fragments into something a dummy like me can understand, I'm going to take a stab at a comprehensive parts list for deleting AHC and setting up stock LC suspension. For me at least, understanding the cost/effort of getting a baseline conventional suspension setup is useful to know. I like AHC and want it to last forever, but I also like to know my options.

As for ride quality and application: the goal is achieve as close to a stock LC ride as possible. Obviously there's no KDSS. This also assumes stock tire sizes, keeping the front sway bar installed, etc. If your goal is to cram more meat in the wheel well, this ain't your list.

I definitely didn't get this right the first time. Please chime in with notes and I will make adjustments to the chart. Once this gets refined, I might create a new thread for easy searching/visibility.


AHC Delete to Stock LC Suspension Parts List

Item​	OEM Part Number​	Qty	Notes
Front LH Spring	48131-60C81	1
Front RH Spring	48131-60D21	1
Front Shocks	48510-69405	2	I believe this comes with the necessary nut 94188-01401
Front Shock Support Sub-Assy	48609-60070	2
Front Shock Cushion	90948-01096	2
Front Shock Cushion Retainer	48597-60120	2
Nut for Front Shock Absorber	94188-01401	2
Bolt/Flange	90105-16088	2	Maybe this can be re-used from AHC?
Nut for Bolt/Flange	94151-21601	2	Maybe this can be re-used from AHC?
Rear LH Spring	48231-60E20	1
Rear RH Spring	48231-60F31	1
Rear Shocks	48530-69445	2
Retainer for Cushion No. 1	90948-02173	4	2 of these go on each shock
Rear Shock Cushion (No. 1 and No. 2)	90948-01064	4	2 of these go on each shock No. 1 and No. 2 cushions are the same part number
Retainer for Cushion No. 3	90948-02170	2
Retainer for Cushion No. 2	90948-02184	2
Nut Lock (top of shock)	90177-14003	2
Bolt w/ Washer (bottom of shock)	90901-19052	2

The next chart is for existing parts that can stay on the LX. I don't know much about sway bars, KDSS, UCAs, LCAs, etc. If one of these parts are viable, but not optimal, I think it's worth calling out so people can make their own judgement calls.


LX Components that work for Stock LC Setup

Item	Note
Rear Sway Bar	Example note: may want to upgrade to thicker sway bar [insert OEM part number]
Front Sway Bar	Example note: can be removed to optimize off-road travel (Is this true? I dunno)
Lower Control Arm	Same part number as LC
Upper Control Arm	Same part number as LC

Lastly, here are the partsouq schematics I referenced.

• Front Shock Schematic
• Rear Shock Schematic

View attachment 3436102
View attachment 3436103

Ok, fire away with feedback. Or ignore if I've totally wasted my time

I recently completed AHC Delete on my 2010 LX, and can help clarify a minimum viable configuration for successful deleting. This may vary depending on the desired height of lift, year of lx, and brand of suspension purchased. I personally went with a ~2" lift from a Bilstein Kit which is designed to utilize stock UCA.
I'll list out the parts I purchased, as well as the tools I used and mark them either required or recommended.

Parts Used:

Part	Description	Price Paid (USD)	Required?
47-31145	B8 6112 - Suspension Kit (front L+R)	$655​	Yes
53-292018	B12 -Rear Coil Spring Set	$193​	Yes
25-311419 or 25-285529	B8 5160 Rear Right Shock Absorber	$295​	Yes
25-311402 or 25-291810	B8 5160 Rear Left Shock Absorber	$295​	Yes
4860960070​	SUPPORT SUB-ASSY, FRONT SUSPENSION, RH/LH (x2) (Land Cruiser Part)	$95​	Yes
48302-60090	Rear Bumper Spring Febest TD-200R (Pair)	$90​	Recommended (appears to be same as LX part)
48810-60051 & 48820-60071	Front Sway Bar End Links (Ebay Price)	$32​	Recommended
48815-60271	Front Sway Bar Bushings (Ebay Price)	$36​	Recommended
9415121001​	Front Strut Top Nuts (x8)	$8​	Recommended
9010516088​	Front Strut Bottom Bolt (x2)	$10​	Recommended
9415121601​	NUT(FOR FRONT SUSPENSION LOWER ARM),RH/LH	$2​	Recommended
9011914079​	Sway Bar endlink Bolt (x2)	$5​	Recommended
9090119052​	Rear Strut Bolt (x2)	$10​	Recommended
	Total Required	$1,533​
	Total Required+ Recommended	$1,726​

Note: With the hardware Supplied with the Bilstein kit, no additional Land Cruiser specific nuts or bolts are needed, however it is recommended to replace these, especially if there is rust. It is important to buy the land cruiser front suspension Spring perch.


Tools :

Tool	Purpose	Required?
Spring compression Kit (can be rented for free from autozone)	To compress and assemble front springs	Yes
Circlip Pliers	To adjust circlip/ ride height setting	No
12mm, 14mm, 21mm ratcheting flex head box wrenches	to improve mental sanity when wrenching in tight areas/ Tightening Rear bolt	No
Milwakee low profile square sided 22mm socket	Can be used in combination with an adjustable wrench to get out the rear bolts in place of special tool	No
8mm Long reach open end wrench >10 inches if possible	To hold the rear strut to prevent from spinning when tightening	Kinda
Bolt extractor Sockets (12mm, 14mm, & 22mm)	Because Rust Happens	No
Sawzall & 9 Inch Metal Blade	If you need to cut off the rear top bolt	No
High Torque Impact	Removing Bolts (Alternatively Big Muscles & a Breaker)	No
8-25mm Socket Set	various Bolts, every size may not be used	Yes

Overall I had a successful Delete with 0 lights on the dash and functioning AFS. Truck was able to be aligned and rides great with a slightly stiffer ride at low speeds (similar to the old high mode) but with improved steering feel and handling on the highway.

**The only issue with the install is that the design of the rear shocks do not work properly with the rear sway bar, and I am currently looking for a drop kit, which only appear to be available in Australia (Rear drop kit example) the rear sway bar does not contact, but it it a bit close for comfort. I deleted it temporarily and the vehicle handles fine for now

Helpful Video Links:
LX570 Suspension Disassembly (non-english)
Watch this if you expect Rusty Nuts
Short Install Video
AHC Disable

Cheers!
AJ

 

[trudd]

I recently completed AHC Delete on my 2010 LX, and can help clarify a minimum viable configuration for successful deleting. This may vary depending on the desired height of lift, year of lx, and brand of suspension purchased. I personally went with a ~2" lift from a Bilstein Kit which is designed to utilize stock UCA.
I'll list out the parts I purchased, as well as the tools I used and mark them either required or recommended.

Parts Used:

Part	Description	Price Paid (USD)	Required?
47-31145	B8 6112 - Suspension Kit (front L+R)	$655​	Yes
53-292018	B12 -Rear Coil Spring Set	$193​	Yes
25-311419 or 25-285529	B8 5160 Rear Right Shock Absorber	$295​	Yes
25-311402 or 25-291810	B8 5160 Rear Left Shock Absorber	$295​	Yes
4860960070​	SUPPORT SUB-ASSY, FRONT SUSPENSION, RH/LH (x2) (Land Cruiser Part)	$95​	Yes
48302-60090	Rear Bumper Spring Febest TD-200R (Pair)	$90​	Recommended (appears to be same as LX part)
48810-60051 & 48820-60071	Front Sway Bar End Links (Ebay Price)	$32​	Recommended
48815-60271	Front Sway Bar Bushings (Ebay Price)	$36​	Recommended
9415121001​	Front Strut Top Nuts (x8)	$8​	Recommended
9010516088​	Front Strut Bottom Bolt (x2)	$10​	Recommended
9415121601​	NUT(FOR FRONT SUSPENSION LOWER ARM),RH/LH	$2​	Recommended
9011914079​	Sway Bar endlink Bolt (x2)	$5​	Recommended
9090119052​	Rear Strut Bolt (x2)	$10​	Recommended
	Total Required	$1,533​
	Total Required+ Recommended	$1,726​

Note: With the hardware Supplied with the Bilstein kit, no additional Land Cruiser specific nuts or bolts are needed, however it is recommended to replace these, especially if there is rust. It is important to buy the land cruiser front suspension Spring perch.


Tools :

Tool	Purpose	Required?
Spring compression Kit (can be rented for free from autozone)	To compress and assemble front springs	Yes
Circlip Pliers	To adjust circlip/ ride height setting	No
12mm, 14mm, 21mm ratcheting flex head box wrenches	to improve mental sanity when wrenching in tight areas/ Tightening Rear bolt	No
Milwakee low profile square sided 22mm socket	Can be used in combination with an adjustable wrench to get out the rear bolts in place of special tool	No
8mm Long reach open end wrench >10 inches if possible	To hold the rear strut to prevent from spinning when tightening	Kinda
Bolt extractor Sockets (12mm, 14mm, & 22mm)	Because Rust Happens	No
Sawzall & 9 Inch Metal Blade	If you need to cut off the rear top bolt	No
High Torque Impact	Removing Bolts (Alternatively Big Muscles & a Breaker)	No
8-25mm Socket Set	various Bolts, every size may not be used	Yes

Overall I had a successful Delete with 0 lights on the dash and functioning AFS. Truck was able to be aligned and rides great with a slightly stiffer ride at low speeds (similar to the old high mode) but with improved steering feel and handling on the highway.

**The only issue with the install is that the design of the rear shocks do not work properly with the rear sway bar, and I am currently looking for a drop kit, which only appear to be available in Australia (Rear drop kit example) the rear sway bar does not contact, but it it a bit close for comfort. I deleted it temporarily and the vehicle handles fine for now

Helpful Video Links:
LX570 Suspension Disassembly (non-english)
Watch this if you expect Rusty Nuts
Short Install Video
AHC Disable

Cheers!
AJ

This is an incredible resource - thank you!

 

[agathos]

As an update, I've contacted AGT Engineering in Australia (CANBUS AUTOMOTIVE SOLUTIONS | AGT Engineering - https://www.agtengineering.com.au/canbus-automotive-solutions) and sent them the 2016 speedometer along with the AHC ECU for them to make me a canbus emulator for the AHC ECU so that no error lights pops-up. I'm waiting for the can-bus module to arrive. once installed and successful, I'll post it here.

Cheers

 

[okcfunky]

I recently completed AHC Delete on my 2010 LX, and can help clarify a minimum viable configuration for successful deleting. This may vary depending on the desired height of lift, year of lx, and brand of suspension purchased. I personally went with a ~2" lift from a Bilstein Kit which is designed to utilize stock UCA.
I'll list out the parts I purchased, as well as the tools I used and mark them either required or recommended.

Parts Used:

Part	Description	Price Paid (USD)	Required?
47-31145	B8 6112 - Suspension Kit (front L+R)	$655​	Yes
53-292018	B12 -Rear Coil Spring Set	$193​	Yes
25-311419 or 25-285529	B8 5160 Rear Right Shock Absorber	$295​	Yes
25-311402 or 25-291810	B8 5160 Rear Left Shock Absorber	$295​	Yes
4860960070​	SUPPORT SUB-ASSY, FRONT SUSPENSION, RH/LH (x2) (Land Cruiser Part)	$95​	Yes
48302-60090	Rear Bumper Spring Febest TD-200R (Pair)	$90​	Recommended (appears to be same as LX part)
48810-60051 & 48820-60071	Front Sway Bar End Links (Ebay Price)	$32​	Recommended
48815-60271	Front Sway Bar Bushings (Ebay Price)	$36​	Recommended
9415121001​	Front Strut Top Nuts (x8)	$8​	Recommended
9010516088​	Front Strut Bottom Bolt (x2)	$10​	Recommended
9415121601​	NUT(FOR FRONT SUSPENSION LOWER ARM),RH/LH	$2​	Recommended
9011914079​	Sway Bar endlink Bolt (x2)	$5​	Recommended
9090119052​	Rear Strut Bolt (x2)	$10​	Recommended
	Total Required	$1,533​
	Total Required+ Recommended	$1,726​

Note: With the hardware Supplied with the Bilstein kit, no additional Land Cruiser specific nuts or bolts are needed, however it is recommended to replace these, especially if there is rust. It is important to buy the land cruiser front suspension Spring perch.


Tools :

Tool	Purpose	Required?
Spring compression Kit (can be rented for free from autozone)	To compress and assemble front springs	Yes
Circlip Pliers	To adjust circlip/ ride height setting	No
12mm, 14mm, 21mm ratcheting flex head box wrenches	to improve mental sanity when wrenching in tight areas/ Tightening Rear bolt	No
Milwakee low profile square sided 22mm socket	Can be used in combination with an adjustable wrench to get out the rear bolts in place of special tool	No
8mm Long reach open end wrench >10 inches if possible	To hold the rear strut to prevent from spinning when tightening	Kinda
Bolt extractor Sockets (12mm, 14mm, & 22mm)	Because Rust Happens	No
Sawzall & 9 Inch Metal Blade	If you need to cut off the rear top bolt	No
High Torque Impact	Removing Bolts (Alternatively Big Muscles & a Breaker)	No
8-25mm Socket Set	various Bolts, every size may not be used	Yes

Overall I had a successful Delete with 0 lights on the dash and functioning AFS. Truck was able to be aligned and rides great with a slightly stiffer ride at low speeds (similar to the old high mode) but with improved steering feel and handling on the highway.

**The only issue with the install is that the design of the rear shocks do not work properly with the rear sway bar, and I am currently looking for a drop kit, which only appear to be available in Australia (Rear drop kit example) the rear sway bar does not contact, but it it a bit close for comfort. I deleted it temporarily and the vehicle handles fine for now

Helpful Video Links:
LX570 Suspension Disassembly (non-english)
Watch this if you expect Rusty Nuts
Short Install Video
AHC Disable

Cheers!
AJ

AJ, *Thank you* for this post. Similarly, thank you to Trudd as well!

I'm compiling a parts list for a full-on baseline, AHC delete, + coil conversion. Your post is supremely helpful.

I'd been waffling between trading my 165K mi 2015 in for a GX, but for the price differential to a decent newish GX being ~15K, this really opens up some options. I put the miles on my LX, and there's a world of difference in feel between it, a 2022 GX (wife's car) and the GX550 (Crawled over one at the dealership last weekend).

How many hours would you say is involved in your AHC delete & conversion? Could it be a Fri night to Sunday morning sort of outlay?

 

[Cruiserhead05]

As an update, I've contacted AGT Engineering in Australia (CANBUS AUTOMOTIVE SOLUTIONS | AGT Engineering - https://www.agtengineering.com.au/canbus-automotive-solutions) and sent them the 2016 speedometer along with the AHC ECU for them to make me a canbus emulator for the AHC ECU so that no error lights pops-up. I'm waiting for the can-bus module to arrive. once installed and successful, I'll post it here.

Cheers

Maybe try to contact Land Cruiser heaven in Maryland. They removed AHC from the owners 2016 and installed OME if memory serves me correct. They may be able to lend a hand.

 

[AJLaz]

AJ, *Thank you* for this post. Similarly, thank you to Trudd as well!

I'm compiling a parts list for a full-on baseline, AHC delete, + coil conversion. Your post is supremely helpful.

I'd been waffling between trading my 165K mi 2015 in for a GX, but for the price differential to a decent newish GX being ~15K, this really opens up some options. I put the miles on my LX, and there's a world of difference in feel between it, a 2022 GX (wife's car) and the GX550 (Crawled over one at the dealership last weekend).

How many hours would you say is involved in your AHC delete & conversion? Could it be a Fri night to Sunday morning sort of outlay?

I think time to completion will depend on condition of the truck, experience level, and tools available. On a brand new truck with no rust and on a lift it could easily be done in a single day. In a truck with tons of rust where every bolt is a fight, it can prove to be a real pain in the ass, especially if unprepared.

In my case it was about 6-8 hours total on the front and probably 10-15 on the rear. My example is likely on the extreme end due to rust troubles and my novice mechanic skills.

The biggest timing risk associated with this job would be not having the right tool or part and getting stuck midway through

 

[Wafflroo]

Going to pick up my kings from filthy Motorsports today. Excited to rip apart my lx and be done with ahc. I’ve enjoyed ahc since I bought my lx just over 4 years ago. Never felt like it was as good as it could be if Lexus had optimized it for off-road use. I think it’s meant for street use mostly. Not trying to stir the ahc pot, I know people have very strong opinions on the subject.

I bought lc kings for mine, so nothing crazy with extended travel or swapping the front end to tundra control arms and coilovers. Has everyone who swapped to lc parts kept their brake lines stock length? Or am I going to need to address the length of the lines (swap to some extended lines)?

 

[propernorf]

Going to pick up my kings from filthy Motorsports today. Excited to rip apart my lx and be done with ahc. I’ve enjoyed ahc since I bought my lx just over 4 years ago. Never felt like it was as good as it could be if Lexus had optimized it for off-road use. I think it’s meant for street use mostly. Not trying to stir the ahc pot, I know people have very strong opinions on the subject.

I bought lc kings for mine, so nothing crazy with extended travel or swapping the front end to tundra control arms and coilovers. Has everyone who swapped to lc parts kept their brake lines stock length? Or am I going to need to address the length of the lines (swap to some extended lines)?

Congrats on your purchase I also removed AHC on my LX for a Ironman Foam Cell Pro kit w/ UCA and I didn't need to replace the brake lines.

 

[jbyrd78]

Congrats on your purchase I also removed AHC on my LX for a Ironman Foam Cell Pro kit w/ UCA and I didn't need to replace the brake lines.

How are you liking the Ironman Suspension on your 570 vs the stock AHC setup? Did you go for a lift, or did you stay at stock height?

 

[bloc]

Has everyone who swapped to lc parts kept their brake lines stock length? Or am I going to need to address the length of the lines (swap to some extended lines)?

I had kings on my LC which I assume had the same lines as your LX, everything worked great.

You probably will have to do quite a bit of grinding to one of the two bump stops for each LCA though, so make sure you have an angle grinder and soft disk. And if you don’t have comp adjusters the fender skirt trimming in the instructions is overzealous.. you can just notch them instead of cutting 3” off the back edge. It’ll make more sense when you see it in person