Afs Sensor Replacement/repair

[Crowtree 6]

Hi Guys after being quoted all but £500 for a replacement sensor by Lexus Norwich have any of you corrected the flashing " AFS Light " on the dash, I have seen posts about adjusting the linkage ? have anybody attempted this and did it work ? Its on a RX400h 2005

Thanks

[bluecraigy 0]

its sgs engineering in Derby who can fabricate the linkage for £55 if its broken there otherwise it is a whole new assembly

[RX400h2005 2]

Hi there. Same car, same problem for me - 2005 RX400h SE-L, flashing AFS light. Found a YouTube video showing the linkage on a different Lexus model, but haven't yet tried to find it on mine. Useful info on the Derby company - thanks!

[lurch 37]

Hi there have you given ian a ring at Roys motor company in norwich? He may be able to help, I know they had a similar issue with a lexus sc430 which they sorted. I always go there for my servicing etc they are excellent and have been looking after lexus and toyota for over 25 plus years, may be worth a call be fraction of cost of lexus.

[steve2006 1,289]

If any one needs one of the linkages PM me as I have some made up.

This is just the linkage not the whole sensor assembly which does cost ££££s

Link below shows the part.

http://evansweb.info/2009/11/23/ls400-ride-height-sensor-repair

[Boxbrownie 53]

Not sure of the size you require but very easy to make your own, you can buy various size ball joints and threaded rod from places like RAPID, RS Components or FARNELL.......similar to this

http://www.rapidonline.com/Mechanical-Fastenings-Fixings/Swivel-Head-Ball-Joint-M5-Steel-523780

[RX400h2005 2]

Can anyone tell me exactly where this sensor and linkage would be on my RX400h 2005? I'm getting a couple of new tyres fitted later and would like to take a look under the car at the same time. Thanks all.

[Crowtree 6]

Can anyone tell me exactly where this sensor and linkage would be on my RX400h 2005? I'm getting a couple of new tyres fitted later and would like to take a look under the car at the same time. Thanks all.

[Crowtree 6]

Off side rear suspension linkage mate. If you take of the wheel you can see it.

[RX400h2005 2]

Great stuff - cheers John

[billygarrett 1]

If any one needs one of the linkages PM me as I have some made up.

This is just the linkage not the whole sensor assembly which does cost ££££s

Link below shows the part.

http://evansweb.info/2009/11/23/ls400-ride-height-sensor-repair

Hi

I would like to obtain a linkage for my RX400h. Is the one you have the same?

I can't see how to PM you, so perhaps you would please tell me how or send me a PM?

Many thanls

Billy

[Boxbrownie 53]

It appears all you need is two ball joints and a section of M5 threaded rodding, as above go to "rapidonline" the two joints and half a metre of threaded brass rod will cost about £6..............or tell me the length between locating holes and I'll sell you one for £50 :winky:

[billygarrett 1]

Thanks for that Boxbrownie!

I should be able to get the brass rod in B& Q and I might be able to salvage the joints. I don't know the part code for rapid online!

It is not urgent as my local garage did a "repair" a while ago for the MOT, but I don't know how long it wil last.

I had previously joined the 2 parts of the broken rod with a piece of electrial type shrink wrap rubber.

That went through 2 MOT's without being spotted, but on the 3rd year he spotted it and passed it provided I had it fixed properly :)

Amazingly the headlamps had stayed in alignment all that time while the rubber did the flexing and the top ball joint was seized up!

This is not to be recommended :)

[Boxbrownie 53]

Rapid Online

51-1692 M5 Steel Ball Joint @ £1.96p each (2 off)

50-8911 M5 Threaded Brass Rod 500mm @ £2.20p each (1 off)

There you go.......well worth having a go with these first, unless upon inspecting the original component you feel 5mm is too small, then there is always the option of using larger balljoints/rodding, but for moving a linear switch I would think these will do fine.

[billygarrett 1]

I have now ordered those items...as well as a couple of waterproof enclosures I need fora broadband customer.

I wasn't aware of that company. It is like Aladin's cave in there!!

Manny thanks

Billy

[RX400h2005 2]

Hi all, still trying to get rid of my flashing AFS light. Most folk seem to be talking about a broken rear linkage - mine seems to be fine. My lights move left & right and up & down when I start the car, so no problems at that end. I've belled out the AFS switch - fine. I suppose the potentiometer itself might be knackered or I guess the linkage might need an adjustment, but it looks nicely centralised...anyone aware of anything else I can try?

[johnmac1956 9]

Hi

Thought I would add a note to this old thread.

My AFS light started flashing recently. Inspection showed that the linkage on the rear sensor switch was in place ,so I removed the switch stripped it and all looked to be in good condition. It is easy to remove 5 mins. I replaced the switch,the AFS light was still flashing. I then started to think that maybe it was another part of the AFS system,which was causing the fault to occur.

I took my car in for a essential care service(another story behind this!!!!) and asked them to quote me for repair of the AFS system.

I was told that 99% of the time the rear height sensor switch is the cause of the AFS light flashing. It was also the same in my case. I was quoted £560 for the supply and installation of a new rear height sensor switch.

Now knowing that it was definitely the rear height sensor which was the cause of the issue. I again removed the switch opened it by removing the 4 screws. Again all looked in good condition. It was very clean with minimal signs of wear or contamination.(80K miles). The electrical contact inside the switch is performed by 3 independent coil springs. I tested the resistance(avo) between the individual springs and the plug connections. I found that although the springs and spring base were in good clean condition. The electrical connection was intermittent.

Basically what was happening is that wear must have taken place around the outer circumference of the copper base where the coil spring sits.This was causing an intermittent electrical connection.

To cure this I bent the last wire of the coil spring so that it went across the middle of the coil spring. Doing so made a good electrical connection between the coil spring and the base of the copper pin connection. Did this on all 3 springs,replaced cover and 4 screws.

Refitted to car (RX 400) and no more flashing AFS light. The whole job took me approx 30 mins. You can access and remove the switch without jacking up the car. But be careful. Handbrake,Keys not in ignition and ideally chock your wheels.

So £560 saved to spend elsewhere.

Hope this may help others.

John

[ChrisKaye 316]

Hi John,

Great job! I cleaned my sensors up a few months back, so know what your talking about.

I've attached a couple of pictures that someone else here kindly put together when they last did this - it has the resistance values to check with your multimeter if you look closely on the paper that the sensor is resting on.

Hopefully this will save anyone hunting further if looking to fix themselves!

Chris.

[johnmac1956 9]

Nice photos Chris.

My sensor switch was in much better condition than that shown in your photos and was still showing a fault. I wonder how many easily repairable switches are thrown away each year by Lexus dealers!!!!

John

[ChrisKaye 316]

At the price they are new individually, it's a crime!

[Clive-D 9]

Read somewhere on a different thread about replacing the O ring at the same time you sort the switch and they gave a supplier link. Anyone seen it please? Just picked up an ‘08 400h with the issue, otherwise super happy with it. Thanks guys. 

[johnmac1956 9]

Do not have link to replacement O ring. I just used silicone sealant to improve the water seal when repairing the AFS sensor switch.

I repaired the it 2 or 3 times before installing a replacement sensor switch. 

https://www.dormanproducts.com/p-72313-924-755.aspx

I think it was this one I purchased but just check it fits your car before purchasing if you do so. The Dorman is not built to the same quality as the Lexus replacement but you can pick them up at a very reasonable price.

[Clive-D 9]

The Dorman is not built to the same quality as the Lexus replacement but you can pick them up at a very reasonable price.

Haha, the Lexus one seems to fail often so doesn’t offer much hope for my namesakes one!!
I was thinking of using sealant but if there was an easy source for the o ring I’d have got one. I’ll give it a try as soon as the weather permits. Will check ball joints not seized too. Thanks for the info - is there a uk stockist?


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[welland 31]

Just found this thread, which looks relevant to my problem, on which I've posted already in another thread.  

The handbook for my rx400h says that The levelling system has a separate warning system if it malfunctions.  This other warning is not triggered for me.  Did any of you who had a problem with this ride height sensor also have the levelling warning on the dash?

[RX400h2005 2]

Yes, flashing AFS light in the R/H clock on the dash. Stopped flashing when I replaced the sensor with a second hand one for about £80 off eBay.