RX300 Air Suspension stuck in high position on one side

trousers1000 · January 27, 2017

Hi guys

sesriously need some help.

i've a RX300 SEL which I've had for 7 years. Low is hard mileage and been a great reliable motor.

recently the air suspension just started playing up.

i will try to explain.

The drivers side of car is in the highest position on both front and rear. Even if i use the height selector the drivers side won't move.

The front near side seems low...but im not sure if this is symptomatic of the high drivers side.

If i select High on the switch i can hear the compressor pump kicking in....but the near side only sometimes will go to high position.

when i select the high position or even Low position, the LED sometimes flashes and sometimes not.

sometimes it will only allow me to select Normal and High (ie not the Low position).

The local garage has connected the computer thingy to it and there are no error logs at all.

I'm not bothered about having the functionality of the height adjustment, so i would be happy to settle for simply being able to get the drivers side lowered to Normal height.

we have had the car on the ramps in the garage and the cant see any visible damage or anything like that.

it's not of a value that is worth justifiying putting the car into the dealership.

Would just like to get it drivable again.

i hope i have explained everything so it makes sense.

please help chaps.

SLACKBLADDER · January 27, 2017

Have you tried disconnecting the Battery just to see if it resets the system

PCM · January 28, 2017

Is there a local Jap/Lexus independent near you who could take a look?

trousers1000 · January 28, 2017

Hi guys

no I haven't disconnected the Battery. If i do so will it affect anything else?

does it really reset by doing this?

SLACKBLADDER · January 28, 2017

I am not sure but most ecu's hold info when Battery has been disconnected but if that bothers you remove the fuse or relay for the suspension and see what that does . Have you recently had the car jacked up with ignition on cuz that can cause suspension problems

PCM · January 29, 2017

Have you also had a really good trawl of this forum?

There might be an existing thread on your same issue?

Haylands · January 29, 2017

First thing I would look at is the height sensors, these are basic hall effect sensors and won't last forever, it should be fairly easy to remove the arm that comes from them to the suspension arm, move the arm as if the car goes down and see what the system does, it could help to diagnose...

Someone with the correct diagnostics should be able to read live values from the sensors to determine if they are faulty or not.

Not sure how many sensors your model has, some have one each side and link the front and back together hence both wheels are running at high height...

I'd say just buy a sensor and try it out but they appear to cost a fortune so it may work out cheaper paying for diagnostics on it...

Most garages can tell you if there is a fault logged but an issue like this is the sensor giving an incorrect reading so you have to have access to, and understand, the live values from the car to diagnose.

Good luck

trousers1000 · January 29, 2017

Slack - yes. Before the suspension started playing up, it had been up on ramps having a power steering pipe replaced. It was one of those ramps which lift from the chassis so in effect the wheels are left free dangling. Hope that makes sense.

What problems can this cause?

SLACKBLADDER · January 29, 2017

If the ignition is on and the car is jacked there is a possibility that if there is adjusters in place at each wheel the compressor will try to make the wheels touch a surface unless the air has been switched off. I've just purchased a 53 rx300 sel and had to replace tyres so kwikfit put the air suspension at max hight before lift then switchedoff ign so no problems I've now found the switch to the air system it's under steering column down near the bonnet release run fingers along the edge from release to centre of car push off push on button.with ign on it shows off at the basement of dash display. With all that in mind that could be the cause of your problems that's if you have height adjustment at each wheel

PCM · January 29, 2017

The-Acre · January 29, 2017

Certainly having the car jacked up with the engine running can cause problems with air suspension, and as suggested disconnecting the Battery should reset it. If not my money would be on the other suggestion which is a height sensor.

trousers1000 · January 29, 2017

Currently sitting on drive with Battery disconnected......watch this space as to the outcome.

i must admit, it is a coincidence that all this suspension hassle started straight after it had been on the ramps for the power steering pipe replacement.

left me thinking either something was disturbed or some other trigger (as suggested by you Slack).

i had a look at it underneath and it looks like there are height sensors in all four corners. Must admit i thought there would have just been a left and right. Doh!

The garage had the computer connected and there are no error logs at all.

the compressor does kick in and i can increase the height of the near side. This makes me think the compressor is fine.

the over riding factors are:

1. The drivers side will not adjust at all.

2. The driver side is stuck in the High position.

report back shortly after a tea break/15 minutes of not Battery connections

trousers1000 · January 29, 2017

Mhmm....

i now have a car that not only has the air suspension problem....but since disconnecting the Battery the engine idling is now a bag of spanners!!

SLACKBLADDER · January 29, 2017

All the ecu's have to educate themselves so it might take a minute or two of driving to re-educate

trousers1000 · January 29, 2017

Slack - honest.....will they....I'm seriously in a low place right now......spanner in hand ready to launch at this motor and bog off to my locall

had this motor for years and loved it...now it's like a wife i want to divorce

SLACKBLADDER · January 29, 2017

Over years of driving lexus and toyota/lexus soarer with air and other fault8ive gone through heartache and I do what your doing asking others now lots of forum members read all they can about thier problems and make a judgement so try driving it around a while but if there are other faults with your car they could become apparent hopefully not

Haylands · January 29, 2017

Yeah, don't worry about the rough running that will sort itself out...

I still say it's a height sensor, when you had it jacked up the sensor will have gone to a place it doesn't go often, when they get a bit long in the tooth they don't like being messed around. As I said you can get this checked by someone using a diagnostic tool that will read the live values from the sensor... Not just fault codes....

trousers1000 · January 29, 2017

Thanks Slack.

is there a safe method for me to simply lower the side which is currently high?

Haylands · January 29, 2017

I imagine there are various ways of bodging the problem, as it's a suspension issue and one that affects other road users if you have a failure, and coupled to the fact that you have published on an open forum that you have a problem with your suspension then I hate to think of the ramifications if you injure someone because you have bodged a temporary fix. I image your insurance will decline any liability and you will be prosecuted...

Your car is not roadworthy unless the suspension is working as intended by the manufacturer....

Take it to a good independant or the dealer and get it fixed properly...

SLACKBLADDER · January 29, 2017

ok I'm not saying go do this but maybe drop car to lowest susp height turn off the compressor locate air feed to the struts slack of let air out retighten turnon air then adjust ride height see what happens. or go to lexus and ask for a diagnostic check I take it the engine has settled down now

trousers1000 · January 29, 2017

Idling has now normalised......and so has my blood pressure io think. Lol

thanks for input guys.

i'm not wanting to bodge it in an unsafe manner or anything like that. My logic is simply to in effect manually adjust the suspension to level as it is not doing it automatically.

PCM · January 29, 2017

We all disconnect batteries at some point. Should not be a problem. Glad your RX is happily relearning ...

Is your little switch in the correct position now?

Still think a good independent is the way to go...

Good luck!

trousers1000 · January 30, 2017

i have determined that it is definately only the drivers side that the issue is with.

i read on the forum that if the computer detects something is not right, then it disables the compressor and then only re-enables it after every three car journeys - ie 3 x cycles of turn ignition on, drive car and then turn ignition off.

This concurs with what is happening....so lastnight go on three journeys and then park up outside my house with engine running. I select the HIGH position and guess what.....the nearside rises so it matches the height of te "stuck on high" drivers side.

I get out and albeit the car is high, it is all level. I turn engine off and leave it overnight.

This morning it is all still high and level - this tells me that there is no leaks. agree?

I then drive off this morning and as soon as i get over circa 10mph the nearside automatically lowers to Normal height (as one would expect), but the drivers side remains in High position.

So no fix as yet, but i know i have no leaks, and i know the nearside is fine. I also know the compressor is fine too.

So....what i am thinking is how do i drain the air out of the drivers side safely. I really could do with some detailed instructions on how to do this.

I can then start her up and see if she then rises to Normal or not.

Is there a paricular connection somewhere that if i slacken it off, it will allow air to drain out?

SLACKBLADDER · January 30, 2017

Why not try the same as what you just done but do it at the normal position if that doesn't work do it at the low position the other thing is if there is a fault code apparent in the brain the car might revert back to the problem until the code is removed first if that makes sense

trousers1000 · January 30, 2017

Hi Slack

tried it in other positions. the car adjusts on the passenger side, but won't on the drivers side - stuck in high.

where does it actually vent from? it obviously has to vent from somewhere in order to lower and presumably there is a vent for each strutt/side?

i wonder if the vent(s) for the drivers side are not working.

Also, because the drivers side is currently stuck in high position, at the moment i don't know whether the drivers side is completely dead or would inflate/readjust if it was at a lower height.

No fault codes showing when the diagnostics machine thingy is plugged in.

hence I would like to drain the drivers side and see if it either 1) stays at the height it is drained to - i would expect this to happen if the entire drivers side is simply non functional at the moment., 2) upon ignition and height selection, then repumps the drivers side back to whatever height is selected be it Norm or High.

unless there is good reason not to do so, for me the next step would be to deflate the drivers side to say "about normal" height and then see if it allows me to select High and see what it does.

If i can see what does/does not function from there......so really am after some learned advice on how to drain the system of air safely.