AHC can of worms have attacked my LX. Seeking advice :)

BigV

New Member
I am in australia
Sep 20, 2019
5
3
3
(may not be related to the AHC issue but I am also getting an ABS, VSC off and check engine light going off constantly even though the car runs fine)

Alright gents im having an issue with the AHC system of my LX470. Car goes down in to low mode and comes back to neutral position no problems but Wont go into high mode at all. When switch is pressed AHC position indicator light blinks twice but returns to "N". Upon checking error codes, c1340 and o2 sensors are the only codes I am seeing so a bit confused would be an understatement. My old man bled the AHC fluid about a week ago and that didnt fix the issue either. Can someone else more knowledgable and experience drop their 2c on what this annoying issue might be?
 

IvanD

Active Member
I am in bulgaria
Dec 11, 2018
69
32
18
Without further information, my bet is that the torsion bars have never been adjusted and your neutral pressures are super high. Might be low on fluid too, although unless there is corrosion and a leak, it is not a consumable.
 

BigV

New Member
I am in australia
Sep 20, 2019
5
3
3
Upon checking techstream data my neutral pressures for front and rears are 7.4 and 7.9. That doesnt seem all to high compared to FSM levels which from what I gathered ranges from 5.5 to 6.9 front and back. This has become a really annoying issue with an otherwise great car lol. Will have a look at adjusting TBs next and see how it goes.
 
Don't like the adverts? Remove them by becoming a supporting member.   Click here

t1pper

Well-Known Member
I am in uk
Aug 7, 2014
337
48
28
I have had a problem like this before where high level was difficult to get, turned out to be a front sensor
It was not a faulty sensor but the linkage was loose and slipping on the spindle part where it connects up to the sensor, linkage moving but did not move the sensor
Also I have had broken links too, my understanding is that if the height sensors do not match with each other within reason the light flashes but no movement.
Carefully check the two sensors on the front suspension and on on the rear axle in the centre making sure everything is in order.
If the lower and neutral positions work it would be reasonable to assume that major components are working,
Only time my car has ever refused to lift was when I had a very heavy cargo of building materials but it would not lift from the lower setting so don't feel your car is struggling as it lifts from low to neutral.
May be weak springs and torsion bars plus the pressures are a bit high but it should work up and down fully with an empty car.
Lastly my own 100 has approximately 250K miles used as a work tool and the AHC has been reliable and the original spheres still seem to have plenty of life left in them only maintenance has been to swap the fluid (special Toyota only) every couple of years as is does work quite hard.
 
  • Like
Reactions: BigV

BigV

New Member
I am in australia
Sep 20, 2019
5
3
3
Noted. Ill have a look at the height sensors and potential discrepancies. Appreciate the help!
 
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock    No Thanks