Have a look at the doc I sent you on Jan 14 - layout is on the 5th page.
AHC, back really high (1 Viewer)
- Thread starter samwise
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Paddo, I know this is an old thread (and there are many other AHC threads), but my LX is having a few issues and you seem to be the AHC guru. I'm having an issue where the rear is making multiple very minor adjustments in park (like down just a little, and then immediately back up); everything else seems to be working fine (goes high and low). I'm wondering if the rear sensor (replaced 3 years ago) is going bad?
I thought I would simply replace just the sensor with the Dorman 924755 (as in the past and discussed above), however the price is now around $90. On the Amazon listing for the Dorman 924755, they also list several other part numbers including part number 89405-48020. When I search for this number, I get results in the $20-$30 range, and even less on ebay.
With my symptoms, do you think a rear sensor replacement is in order, and/or any reason to not try one of the cheaper ones (yes, I am cheap...)?
Lee
'04 LX470
'00 LC
Multiple minor leveling corrections isn’t normal, it should relevel and settle smoothly. Definitely a possibility you’ve found the limit of the aftermarket units durability, could be moisture ingress or a harness/connector problem too. I guess I’d inspect and clean the sensor, connectors and lever mechanism first and see if the leveling stuttering resolves. But I like experimenting with the system too.
Interesting that the price of the Dorman unit has almost doubled in the last couple of years and it also seems that there are more aftermarket manufacturers now at lower price points than Dorman. Worth a shot going with the cheaper options - possibly they all come out of the same factory. Who knows.
The Aisin complete units at ~$150 maybe a better option for some looking to repair/replace height sensors as you don’t have to graft the sensor on to the bracket and lever. Seems that despite posting caution warnings to do this easy operation with some care peeps are inadvertently over rotating the potentiometer wiper stub when tightening down the lever lock nut. This ruins the sensor and causes both random or consistent height feedback problems and muddies diagnosing a system that’s not behaving because people are convinced “it’s not the sensor because i just replaced it”. It’s nearly always a sensor.
Paddo, once again your wisdom looks spot on and much appreciated!!! THANK you again!
I wonder if I damaged the potentiometer on the one I installed 3 years ago and maybe shortened its lifespan??? Either way, I'm going to install a new sensor...
I did notice that on the Dorman the black rubber around the keyed bolt looks thicker and sticks out beyond the gray plastic case, and on the other less expensive aftermarket units it looks thinner and is even with the gray plastic case. Maybe this is just an older stock picture (I can't remember what the one I replaced 3 years ago looked like).
I was surprised to see that the Dorman has increased in price ($90), and that the Aisin complete assembly was now around $150. Regardless, I have ordered a $20 "Bapmic?" unit off of Amazon and will try it. I will post results when I get it installed.
Thanks again!
Lee
I wonder if I damaged the potentiometer on the one I installed 3 years ago and maybe shortened its lifespan??? Either way, I'm going to install a new sensor...
I did notice that on the Dorman the black rubber around the keyed bolt looks thicker and sticks out beyond the gray plastic case, and on the other less expensive aftermarket units it looks thinner and is even with the gray plastic case. Maybe this is just an older stock picture (I can't remember what the one I replaced 3 years ago looked like).
I was surprised to see that the Dorman has increased in price ($90), and that the Aisin complete assembly was now around $150. Regardless, I have ordered a $20 "Bapmic?" unit off of Amazon and will try it. I will post results when I get it installed.
Thanks again!
Lee
Update to AHC making multiple leveling corrections.... sensor replacement: I received the $23 sensor (part number 89405-48020) from Amazon, and it looked almost identical to the Dorman unit. The rubber grommet/washer around the keyed bolt was different, but other than that, exact fit.
The short story is that I replaced the sensor with the $23 unit from Amazon, and everything is working as expected. No more continuous slight adjustments, and everything is good! To quote Paddo, "It's nearly always a sensor..."
Because I had replaced this sensor about 3 years ago with the Dorman, I wanted to see if I could figure out the fault in the old Dorman sensor. The first thing I noticed on the 3 year old Dorman that I replaced was the broken rubber grommet/washer (grommet is probably not the right word), which was falling off once I removed the sensor. See pictures below of the old one (still in the bracket) on the right and the new $23 dollar one on the left:
Here is another picture of the the old Dorman out of the bracket with the rubber grommet which fell off:
Seeing the rubber grommet off, I assumed that maybe moisture or dirt got in and damaged the sensor. I opened the sensor, and didn't see anything that looked too out of place. The copper springs looked good, the contacts had some gunk on them but looked ok, and the traces had some grease on them (which seemed an odd color). Feel free to let me know if there is something there that I'm not seeing. See below:
I'm wondering if it was just some dirt or something small that was affecting one of the contacts. I probably could have cleaned it and put it back together and everything would be fine.
Regardless, I installed the new $23 sensor from Amazon and everything is working good now. I will keep the Dorman, and maybe clean it and keep it for a spare...
Bottom line is that the $23 sensor from Amazon is working fine for the time being... Time will tell.
Lee
2000 LC
2004 LX (with new rear AHC sensor)
The short story is that I replaced the sensor with the $23 unit from Amazon, and everything is working as expected. No more continuous slight adjustments, and everything is good! To quote Paddo, "It's nearly always a sensor..."
Because I had replaced this sensor about 3 years ago with the Dorman, I wanted to see if I could figure out the fault in the old Dorman sensor. The first thing I noticed on the 3 year old Dorman that I replaced was the broken rubber grommet/washer (grommet is probably not the right word), which was falling off once I removed the sensor. See pictures below of the old one (still in the bracket) on the right and the new $23 dollar one on the left:
Here is another picture of the the old Dorman out of the bracket with the rubber grommet which fell off:
Seeing the rubber grommet off, I assumed that maybe moisture or dirt got in and damaged the sensor. I opened the sensor, and didn't see anything that looked too out of place. The copper springs looked good, the contacts had some gunk on them but looked ok, and the traces had some grease on them (which seemed an odd color). Feel free to let me know if there is something there that I'm not seeing. See below:
I'm wondering if it was just some dirt or something small that was affecting one of the contacts. I probably could have cleaned it and put it back together and everything would be fine.
Regardless, I installed the new $23 sensor from Amazon and everything is working good now. I will keep the Dorman, and maybe clean it and keep it for a spare...
Bottom line is that the $23 sensor from Amazon is working fine for the time being... Time will tell.
Lee
2000 LC
2004 LX (with new rear AHC sensor)
Is the sensor hard to change and were is it located ? .
@Dannyboy lx470, It is really pretty easy (note I have only done the rear sensor). It only took me about 20 -30 minutes, and that is going slow. I'll try to describe in detail below for the rear sensor, but the details makes it seem a lot harder than it is.
I put the rear wheels on ramps (highly recommended (ramps are great, just back up on the ramps), I guess a lift would be better), and then jack stands on rear axle in case ramps fail; that way I could easily slide under the rear axle and get to everything.
The rear sensor is located above and slightly in front of the rear axle on the left hand side of the vehicle. The AHC linkage attaches to the sensor on the keyed bolt on the sensor. The sensor is held in place by a bracket that attaches to the frame with two bolts. Here is a picture that I stole from another post by @RayW (this picture is in front of rear axle, looking towards the rear of the vehicle):
Hope the picture helps.
1. I unplugged the wiring connector on the sensor (pinch tab and pull). Note that there is a plastic clip holding the wires in place on top of the bracket, I removed this clip by pushing it out of the hole in the bracket (might be easier to do this once the bracket is unbolted in step 3 below).
2. Then I removed nut on the keyed bolt (part of the sensor), leaving the AHC linkage (assuming you don't need to adjust - adjustment can be made at the other end of the linkage).
3. If I remember correctly, there are two bolts holding the bracket to the frame (10mm or 12mm, can't remember). I removed these two bolts.
The I removed bracket and sensor, see picture below (note that the hole in the top of the bracket is for the plastic clip mentioned in step 1 that holds the connector wiring up and out of the way):
4. I removed the three philips screws holding the sensor in the bracket.
5. I installed new sensor into bracket using the 3 screws (there are some plastic pins in the sensor to align it and I believe it will only go in one way).
6. I re-attached the bracket (and sensor) to frame using the 2 bolts.
7. I re-attached the AHC linkage to keyed bolt on sensor. It can be a little wierd figuring out how the linkage goes, but the first picture in this post should help. Also, this keyed bolt is attached to the contacts inside the sensor, be careful tightening the nut on this bolt (or over rotating the keyed bolt) as I presume you could damage the contacts in the sensor (as Paddo mentions in a post above).
7. I reconnected wiring connector and plastic clip in bracket that holds wiring out of the way.
Done. Its really not as complicated as the steps above sounds. If I had to do it again, I think I could do it in about 15 minutes.
Hope this helps.
Lee
I put the rear wheels on ramps (highly recommended (ramps are great, just back up on the ramps), I guess a lift would be better), and then jack stands on rear axle in case ramps fail; that way I could easily slide under the rear axle and get to everything.
The rear sensor is located above and slightly in front of the rear axle on the left hand side of the vehicle. The AHC linkage attaches to the sensor on the keyed bolt on the sensor. The sensor is held in place by a bracket that attaches to the frame with two bolts. Here is a picture that I stole from another post by @RayW (this picture is in front of rear axle, looking towards the rear of the vehicle):
Hope the picture helps.
1. I unplugged the wiring connector on the sensor (pinch tab and pull). Note that there is a plastic clip holding the wires in place on top of the bracket, I removed this clip by pushing it out of the hole in the bracket (might be easier to do this once the bracket is unbolted in step 3 below).
2. Then I removed nut on the keyed bolt (part of the sensor), leaving the AHC linkage (assuming you don't need to adjust - adjustment can be made at the other end of the linkage).
3. If I remember correctly, there are two bolts holding the bracket to the frame (10mm or 12mm, can't remember). I removed these two bolts.
The I removed bracket and sensor, see picture below (note that the hole in the top of the bracket is for the plastic clip mentioned in step 1 that holds the connector wiring up and out of the way):
4. I removed the three philips screws holding the sensor in the bracket.
5. I installed new sensor into bracket using the 3 screws (there are some plastic pins in the sensor to align it and I believe it will only go in one way).
6. I re-attached the bracket (and sensor) to frame using the 2 bolts.
7. I re-attached the AHC linkage to keyed bolt on sensor. It can be a little wierd figuring out how the linkage goes, but the first picture in this post should help. Also, this keyed bolt is attached to the contacts inside the sensor, be careful tightening the nut on this bolt (or over rotating the keyed bolt) as I presume you could damage the contacts in the sensor (as Paddo mentions in a post above).
7. I reconnected wiring connector and plastic clip in bracket that holds wiring out of the way.
Done. Its really not as complicated as the steps above sounds. If I had to do it again, I think I could do it in about 15 minutes.
Hope this helps.
Lee
Just wondering if you guys need to do something to reset values from techstream. I installed all new senors but one side is reading 30 mm and the other side is -33 mm??? Is there a right side dorman vs a left side dorman that I should have installed?
Nvm I found my answer in the ABCs of ahc
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Nice work! Very nice looking LX.
Beware those aftermarket height sensors seem to have a near 0% success rate long term. Let us know how it does for you over the next few months.
Hmm, but it might make it so that I can change out my other two sensors as well and see if that fixes my AHC problem. I didn't think we even had cheaper options.
Heck Amazon has free returns...
If you don't mind the time and effort then sure. If your free time is worth $50/hr and you burn two 2-hour sessions futzing with an aftermarket R and R then you're probably better off just buying OEM.
Is that the same sensor across the two front and the back ?
My AHC has been acting funny last weekend. Deciding to stop working after a 2 month hibernation. Next day normal service was resumed but I decided to change the 3 sensors and the AHC pump to ensure reliable service.
Also what the final verdict on Dorman ? Is that considered a quality product or shall I go for Aisin (the original OEM product). In the UK the dorman is 100 gbp vs chinese part at 23 gbp (not very keen on that one). Is there a way to purchase only the Aisin sensor (the existing metal frame and arm are good) ?
My AHC has been acting funny last weekend. Deciding to stop working after a 2 month hibernation. Next day normal service was resumed but I decided to change the 3 sensors and the AHC pump to ensure reliable service.
Also what the final verdict on Dorman ? Is that considered a quality product or shall I go for Aisin (the original OEM product). In the UK the dorman is 100 gbp vs chinese part at 23 gbp (not very keen on that one). Is there a way to purchase only the Aisin sensor (the existing metal frame and arm are good) ?
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I've never seen a single person successfully use the Dorman sensors. 100% failure rate from what I've read. Aisin or better yet genuine OEM. I've had plenty of Aisin parts fail shortly after install. Never had a single genuine Toyota/Lexus part fail. They are not the same thing, even if Aisin is/was the supplier for Toyota.
Good warning by @suprarx7nut -- reminds of a warning about fake AISIN parts brought to attention by @cruiseroutfit :
Possible fake AISIN water pumps in AISIN timing belt kits - https://forum.ih8mud.com/threads/possible-fake-aisin-water-pumps-in-aisin-timing-belt-kits.1290877/#post-14908785
Suggest be careful -- stay with known reliable suppliers with good reputations on IH8MUD, especially when OEM parts are required.
In my case, new Height Control Sensors were ordered using the relevant Toyota Part Numbers from Partsouq -- about whom I have never had cause for doubts about reliable OEM Toyota/Lexus supply -- but would be interested to know if others have had different experiences?
See new replacement Front Sensors out of the box from Partsouq and on the vehicle being adjusted in July 2020 as shown below -- no problems with these so far -- but it is early days in the life of a Sensor. These were marked "TOYOTA AISIN" on the Front Sensors, and "AISIN TOYOTA" on the Rear Sensor (zoom in to see). The original factory-fitted Sensors taken off this 2006 LC100 with AHC had the same markings stamped in the metal in exactly the same way.
Given the cross-shareholdings Toyota has with some of its major component suppliers -- AISIN, DENSO, KYB, others -- and their shareholdings in Toyota, this comes as no great surprise -- but what is marked on a nice-looking box may not be the Real Deal, so suggest be suspicious of unproven sources of supply. If there is a deal advertised on AHC Height Control Sensors which looks too good to be true, then maybe it ain't true!!
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how am i only just now finding this thread... this seems to address all of my ahc problems. the rear sensor is now almost $500, which is absolutely insane to me. i think the dorman might be worth a shot, especially considering I value my time at $0/hr.
89407-60010 TOYOTA , 8940760010 New parts search — IMPEX JAPAN
en.impex-jp.com
Yes -- USD259 + shipping is a lot to pay for a Rear Height Control Sensor but worth it for OEM reliability and longevity.
since you're awake and i'm stressing out about it, do you think it's ok that i drove my truck for 5ish minutes going 70mph+ fully on the bumpstops?89407-60010 TOYOTA , 8940760010 New parts search — IMPEX JAPAN
Yes -- USD259 + shipping is a lot to pay for a Rear Height Control Sensor but worth it for OEM reliability and longevity.
