Swap to standard suspension, rides so much better with OME.
AHC works, High light Doesn't
- Thread starter Gebo
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Today when I went to pull my running boards I went to put the truck into high mode and it seemed to lift as normal, rear first then the front but the "H" indicator went from flashing back to a solid "N". The truck did not lower to normal though.
Back story, I adjusted the height sensors and also cranked the TBs to reduce pressure (2 turns each side) about three weeks ago.
Only difference I noticed when lifting after the adjustment is that the front would raise a little bit after the rear, pause, then lift again. Now it doesn't do that second lift. If I shut the car off and restart it the "H" light is illuminated and the front end then lifts to where it should be. Sound like the same problem? Do I need to crank some more?
Back story, I adjusted the height sensors and also cranked the TBs to reduce pressure (2 turns each side) about three weeks ago.
Only difference I noticed when lifting after the adjustment is that the front would raise a little bit after the rear, pause, then lift again. Now it doesn't do that second lift. If I shut the car off and restart it the "H" light is illuminated and the front end then lifts to where it should be. Sound like the same problem? Do I need to crank some more?
Yes it does. Yes you do. You should get them adjusted to give the correct oil pressure at the Normal position though, rather than just crank the bolts a few more turns.
TBs will weaken over time, so your AHC may have been a bit over pressured before you fiddled . . . err . . . adjusted the sensors.
- Thread starter
- #44
Just crank them a couple of more turns and then check it out. It fixed mine.
FYI< I even called the 2 closest Lexus dealers and talked to service about getting my TB's adjusted and then checking the pressure in the AHC system. They did not know anything about checking the pressure and both said they had never done it before. I was willing to pay to get them adjusted per the manual. Go figure. One guy was nice enough to fax me the pages in the FSM so I could "DIY".
FYI< I even called the 2 closest Lexus dealers and talked to service about getting my TB's adjusted and then checking the pressure in the AHC system. They did not know anything about checking the pressure and both said they had never done it before. I was willing to pay to get them adjusted per the manual. Go figure. One guy was nice enough to fax me the pages in the FSM so I could "DIY".
Can you comment exactly on the process to achieve factory pressure? Is there a special pressure guage or something? Where do you hook it up to?
Just crank them a couple of more turns and then check it out. It fixed mine.
FYI< I even called the 2 closest Lexus dealers and talked to service about getting my TB's adjusted and then checking the pressure in the AHC system. They did not know anything about checking the pressure and both said they had never done it before. I was willing to pay to get them adjusted per the manual. Go figure. One guy was nice enough to fax me the pages in the FSM so I could "DIY".
I'm just going to play around with it I think, the service advisors at my dealer are complete idiots when it comes to anything mechanical, they didn't even know what AHC was when I called about fluid so I doubt they'll know about the pressures.
Rod, is there a specific process to this? I don't remember reading it within the thread but I may have over looked it.
Yes, there are two methods to do it described in the FSM. One is by measuring a voltage from the pressure sensor using the Lexus/Toyota hand-held tester, and the other is to put hydraulic pressure guages onto the bleed valves of the Hydraulic Actuators, which is what the spheres are attached to.
Since you have adjusted the height sensors I think you need to use one of those methods, although you could just keep cranking the TBs until the AHC seems to work correctly again. (Not advised.)
There is a little information in this thread: https://forum.ih8mud.com/100-series-cruisers/334173-ahc-height-sensors-question.html. Some more in https://forum.ih8mud.com/100-series-cruisers/363680-ahc-mini-lift.html.
Because I was replacing the Actuator Spheres with some custom pressure units from B&B Suspension, and compensating for the extra weight on my truck, I bought one of these pressure testing guage sets to test all pressures and adjust the front TBs: Waekon BEQ0397 ABS and Brake Pressure Testing Master Kit. It worked well.
To adjust the TBs, just make sure you have both front wheels off the ground first, so that you aren't lifting the vehicle as you tighten them, or worse, the AHC kicks in and lowers the vehicle while you are under it! Note that to compensate for the extra weight on my truck, and reduce the oil pressure in the AHC below the specification, I had to turn the TBs 14 full turns. I didn't make any changes to the height sensors.
Unfortunately I only have a paper copy of the FSM, and I don't have a working scanner at the moment, so I can't send you the pages. Perhaps Gebo could send you over a copy?
Hmm...I may try to call up my dealer and possibly talk to a tech to see how much work it'd be/cost to have it checked. It seems to go into high now ok but I should probably have the pressure checked out so I don't have the AHC fail any sooner.
Called the dealer, talked for 20 minutes, got nowhere. He kept saying I needed to just change the fluid and that would solve my problems since nothing goes bad with these systems. I told him probably the same thing 10 times but to no avail. He said it would cost at least 92 bucks to have it just drive it to the shop to have looked at. I think I'm gonna try other options, any ideas?
Well, the pressure guages I mentioned above. But they will cost you US$300, or a bit less if you search around. Maybe someone near you has a set you can borrow.
Or search around here for a way to use the elctrical measurement, without having the Lexus/Toyota hand-held tester. I'm pretty sure it can be done, just measuring a voltage on the correct pins in the diagnostic test plug, or something like that. I haven't research it though.
Other than those, or finding a new dealer, I guess you can just crank the TBs until the ride feels right, and it lifts and lowers properly, within the time specified in the FSM.
Low to Normal or Normal to High: 15 Seconds or less
Normal to Low or High to Normal: 10 Seconds or less
Wait at least 5 seconds between tests to let the AHC settle and lock into position.
I can't help much more until I get a scanner working to scan pages of the FSM. Even then, it just provides more information about the pressures to achieve, and a bit more methodology.
Or search around here for a way to use the elctrical measurement, without having the Lexus/Toyota hand-held tester. I'm pretty sure it can be done, just measuring a voltage on the correct pins in the diagnostic test plug, or something like that. I haven't research it though.
Other than those, or finding a new dealer, I guess you can just crank the TBs until the ride feels right, and it lifts and lowers properly, within the time specified in the FSM.
Low to Normal or Normal to High: 15 Seconds or less
Normal to Low or High to Normal: 10 Seconds or less
Wait at least 5 seconds between tests to let the AHC settle and lock into position.
I can't help much more until I get a scanner working to scan pages of the FSM. Even then, it just provides more information about the pressures to achieve, and a bit more methodology.
.OME.
wildsmith
SILVER Star
Toyota should do a recall to remove AHC and fit OME springs and Darrens Bilstein shocks
I got ahold of the FSM and here's what it says for anyone that'd wanna see this...I'm gonna try and take it to them and see what they can do otherwise I'm tackling this somehow
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