1990LS400

The battery in one or more of your TPMS sensors may have failed. An internet search indicates that the batteries last between 5 and 10 years. My understanding is that the batteries cannot be replaced and that it is necessary to purchase new sensors and reprogram the vehicle ECU with the ID codes.

I've used a mechanics stethoscope several times to track down interior noises. They are fairly cheap ... I see one online for about $12. Sometimes I've had someone else drive while I probed around the interior with my stethoscope. The sources of the noises have usually been something rattling around in the center console, glove compartment or door pocket. The source of a particularly nasty buzz turned out to be a loose setting in a ring on my right hand which was pretty funny - the buzz occurred only when my right hand was on the steering wheel. Another common source of buzzes are the little servo motors opening and closing flaps in the HVAC system to regulate the interior temperature. You can eliminate that possibility by turning your HVAC off and seeing of the buzzing stop. There's not much one can do to stop the buzzing from that since it's considered normal unless it is really loud.

The hydraulic hood support struts are worn out. A sign of wear is when they keep the hood up in warm weather but not in colder weather. Here are the OEM part numbers from https://www.toyodiy.com/ SUPPORT ASSY, HOOD, RH - 53440-0E020 SUPPORT ASSY, HOOD, LH - 53450-0E010 Googling the part numbers should find both OEM and aftermarket replacements. They are fairly easy to replace. I've replaced several sets

It has been 17 years since I sold my 1990 LS400 so my memory could be hazy. Can you essentially deactivate the tilt/telescope by moving the steering wheel to your preferred driving position and then setting the Auto button on the left side of the steering column to its "off" position? The "off" position for this button is when it is extended. The 1990 LS400 owners manual shows fuse #27 as being for the steering wheel and seat belt anchor but pulling it will also deactivate the power windows and sunroof. I don't know if the tilt/telescope can be deactivate through the diagnostic port. The 1990 LS400 didn't have an OBD2 port like the LS430 did. A lot of customizable features were added to the LS430 in 2001. The 2000 LS400 I owned was assembled several months after the 2001 LS430 went on sale in some countries but it didn't have nearly as many customizable features through the ODB2 port as the LS430.

It is usually necessary to pull audio system head units to access their antenna connections. If you are going to the trouble of pulling the head unit, consider installing a device that allows you to stream audio from your phone through an aux-in cord or wirelessly through Bluetooth which should provide far better sound quality than an FM modulator. VAIS Tech has been selling these interfaces probably longer than anyone else. Stores like Best Buy might have them too or just do an internet search. I see some on Amazon. Here is a link to the VAIS website: https://www.vaistech.com/ Here is a link to instructions on how to remove the head unit from a company that makes phone brackets: https://cdn.shopify.com/s/files/1/0263/3901/6785/files/MV-50-03-L-p1.pdf_Lexus_RX400_06-09.pdf?v=1602872653 It is usually pretty easy to pull a head unit if you have right tools and maybe some experience. Installing the type of interface I mentioned above would probably take no more than 30 minutes.

Summarizing the three methods for carrying bikes that have been mentioned in this thread: 1. Use a general purpose bike rack that attaches to the trunk/hatch door with straps. 2. Buy the UX cross bars and attachments for carrying bikes on the roof. 3. Have a custom receiver hitch fabricated and use a hitch mount bike rack. I can think of a forth option but it would likely be the most expensive one. Buy the European market hitch for the UX and the European market bike rack that can be mounted on it. I bought European market parts from a Lexus dealer in London in the early 1990's by phone before the Internet was viable. The London Lexus dealer appeared to have bypassed U.S. customs and I did not have to pay import duties. Regardless, that Lexus dealership no longer exists and has been replaced by a BMW dealership at the same address. Finding a U.K. or European Lexus dealer that ships to the U.S. might be difficult. If you really want to carry your bicycles on your UX, don't need a trailer hitch for anything else, and have the physical ability to lift your bicycles up to a roof rack, then why not carry them on a roof rack? As much as I dislike carrying bikes on roofs, I did it for 11 years on a mid-size Mercedes sedan using a La Prealpina roof rack that had attachments for both bikes and snow skis. The wind noise from the rack and bikes was unpleasant and worried that I might forget that the bikes were up there but that was the price of transporting our bikes. Have you investigated whether or not there are hitch fabricators near where you live? There's one within 10 miles of my home here in Kansas. At least I think they still fabricate hitches since they did 20 to 30 years ago. That business was started in the 1930's and is still run by the same family.

A suggestion is to read the previous posts in this thread and take action based on what others have found.

YO! I found them in the roof panel / back glass diagram! They aren't shown as a separate replaceable part which probably means that they are welded in place. You must really hate those suckers to want to remove them. There aren't many SC430's left on the road. I doubt if I see one a year and it's probably the same one I sometimes see at the Costco gas pump. Edit: OK, I found a photo showing the roll bars inside the head rest covers.

Here is a link to a old thread on the Club Lexus forum about it: https://www.clublexus.com/forums/sc430-2nd-gen-2001-2010/133149-roll-over-protection.html There seems to be a dispute in the thread about whether or not these things are roll bars. One person said that Lexus corporate said they weren't and another quoted a brochure that says they are. Roll bars are not shown in the parts diagram for the 2002 SC430 - at least in the rear seat diagram. Were they available in a later model year? If so, could a prior owner have adapted them from a newer model? Could your roll bars be aftermarket? I've seen a bunch of nice looking roll bar kits over the years. Got a photo of them? I'll continue to look through the parts diagrams. The diagrams that show the rear seat headrests don't show them but maybe someplace in a structural diagram shows them.

The SC430 does not have roll bars. The covers behind the rear headrests are only that - cosmetic covers. Looking at the parts diagrams, it appears that the covers behind the headrests are held in place by screws or bolts.

You could probably have a receiver hitch fabricated without going to Arizona to have it done. Some full service trailer supply companies fabricate receiver hitches. There's one near me here in the Kansas City area and you might find one or more where you live if you check around.

A number of component problems can cause limp mode. The only time it happened on my similar 2000 LS400 was when either the pedal position sensor (PPS) or throttle position sensor (TPS) started to fail. There are instructions in the repair manuals on how to test these sensors. The sensors are rather expensive so you don't want to replace them blindly without confirming that they are defective. It my case, one of the sensors was intermittently failing (I forgot which sensor) and the other shown signs of weakness when tested. I went ahead and had both sensors replaced by an independent repair shop that specialized in Lexus vehicles.

Your mechanic "guessed"? Maybe you need a technician with diagnostic skills ... perhaps a Lexus dealership.

Having owned a similar 1990 LS400 from new until 2003, I would suspect that your performance issue is in the induction system and most likely in the throttle body. The throttle body is easily damaged. This is something best left to a professional technician. Your speedometer problem is is most likely in the speedometer itself. it is extremely common for the needle to stick, occasionally operate and be inaccurate. These guys should be able to help you: https://www.taninautoelectronix.com/

Are the bulbs in good condition? Bulbs can deteriorate over time with the glass globes becoming brownish and inhibiting light. You could add one or more additional backup light units - perhaps attached to the bumper cover. Google "backup lights" and you should find aftermarket units. The attached photo shows rear fog lights that I installed on two vehicles. The same seller on eBay Germany has backup lights that look identical. I had to fabricate "L" brackets to install them. You would have to tap into the backup light circuit on your RX.

I drove LS sedans for 24 straight years - a 1990 purchased new and an off lease 2000 that I bought at 38,000 miles in 2003. I owned the 1990 until a few months after I bought the 2000 LS which I drove until 2014. I spent at least $1,000/year on maintenance and repairs on each vehicle during the final several years I owned them. Lexus LS are wonderful vehicles but they are expensive to maintain if you keep everything working properly. I probably "over maintained" these cars. Synthetic oil and filter changes every 5,000 miles and transmission and differential fluid changes every 30,000 miles. But they both ran perfectly and didn't use a drop of engine oil between changes when I both cars when they reached about 180,000 miles. During all this, I never had a single maintenance procedure performed that was not specified in the maintenance manual except for more frequent transmission and differential fluid changes. The local Lexus dealership would try to pressure me into buying some pretty bizarre unnecessary maintenance procedures but I just said NO. I never had brake pads replaced until the wear sensors triggered warnings. I had most of the maintenance and repairs after the warranties expired done at two independent repair shops owned by former Lexus dealership service writers - prices were a little less and there were no attempts to upsell service. Control arms and other suspension components seem to be the Achilles Heal of the LS460 but earlier LS generations had their share of suspension problems too. I would think that Toyota should be able to design more robust suspension components but maybe that's not compatible with nice ride characteristics. My wife complained for years about Lexus maintenance costs but she misses the plush ride. So, yeah, these cars are expensive maintain but not nearly as expensive to maintain as European luxury sedans such as Mercedes and BMW. The last Mercedes I owned, purchased new, was on its third engine when I dumped that P.O.S. after 10 years and 225,000 miles. That should make your LS460 sound pretty good! You might want to look for an independent Lexus repair facility if you are using the Lexus dealership. $300/hour for labor is ridiculous.

I can't tell you where the problem is but only that the ABS system has been one of the causes mentioned n past threads on the Club Lexus forum. Maybe a Lexus dealership tech can diagnose the problem - it's beyond my skills.

Well ... it can take a lot of cash to keep these cars going as they age. I spent around $1,000 per year on repairs and maintenance in the last several years I owned the 1990 LS400 that I bought new and sold in 2003. Maybe advertise it on Craigslist. There are people out there who value these cars.

The LS430 used a somewhat crude method that senses tire rotation using the four ABS sensors and compares the rotation rates to determine if one is different from the others. If all the tires match and have similar wear, then the problem could be in the ABS system. Yours is a fairly common problem.

It's the originator of this thread that needed the information - not me. I use the same resources but through the Johnson County Kansas public library. I don't recommend these resources to people on forums since many people don't have library cards, some libraries don't allow online access and many libraries don't subscribe to these resources. We are fortunate that our libraries in Kansas for our libraries to do.

https://www.taninautoelectronix.com/product/1990-2000-lexus-ls400-instrument-cluster-repair/

If no one answers you could ask on the much more active ClubLexus generation 4 RX forum: https://www.clublexus.com/forums/rx-4th-gen-2016-present-273/ I would think that the steering wheel buttons should light up when the parking lights or headlights are on. Even all the steering wheel buttons on our 2012 Prius and 2014 Sienna light up. If they don't light up, the spiral cable behind the steering wheel hub could have a broken wire or connection. The lights for these buttons aren't going to be on a separate circuit.

I'll answer since no one else has. It's impossible to tell what, if anything, a previous owner did to disable the navigation screen. Maybe the DVD drive failed. Regardless, it wouldn't be of much value since the last map update was in 2013. I wonder if a portable navigation device could be adapted to fit in the space occupied by the OEM screen. If I was going to try to do something like that, I would see if a Garmin Zumo XT 5.5" unit could be adapted to fit. The Zumo is designed for motorcyclists and might be more suitable for use in a convertible than other portable navigation products. The Zumo can be linked to a motorcyclists headset which makes me wonder if it could also be linked to a portable Bluetooth speaker for use in your SC so that you could better hear its turn-by-turn instructions. I've hardwired portable Garmin devices into older vehicles (2000 Lexus LS400 and 1998 Toyota Camry) and mounted them on brackets I created using a combination of off-the-shelf components and components I fabricated. Mounting a Zumo would likely require a custom mount and bezel although using the motorcycle mount that comes with the Zumo as a starting point has advantages. BTW, the Zumo also has a handsfree phone feature. Another cool feature of the Zumo is that it can get map updates by directly connecting to a WiFi network instead of having to connect it to a Windows PC. Respond here or PM me if you want to discuss this further.

What is this "light control module"? According to the parts lists I checked, headlights should be interchangeable between the 2000 and 2002 RX as long as they are of the same type - halogen or HID. Converting an RX from halogen to OEM HID is VERY difficult and expensive if done correctly. Converting an RX from OEM HID to halogen is less difficult but would require rewiring and splicing in different bulb connectors and perhaps using an aftermarket relay to power the halogen low beam bulbs. You won't be using the HID ballasts if you are doing that. If that is what you are doing, be careful since the ballasts carry high voltage. Wiring diagrams are on the fee based https://techinfo.toyota.com/

Noise #1 might be the HVAC system fan. They sometimes wear out or debris gets in contact with the fan blades. I think it was loose duct insulation that once contacted the HVAC fan blades on my first LS around 25 years ago and made some irritating noise. A tech quickly extracted the debris. HVAC fans usually aren't terribly difficult to replace if they fail. Noise #2 might be a servo driven HVAC duct flap opening or closing or maybe retrying to open or close due to its movement being inhibited. Is this vehicle new to you? Some of these HVAC servos sometimes open and close flaps a LOT in normal operation - over and over and over.