Speedometer and dash lights not working properly and Code PO500

Clearing the codes will not turn off any lights if there is a failure turning them on. A speed sensor failure would cause all of those lights as the ABS and Stability Control both use the sensor for operation. In reality they are the same systems, stability control works using the ABS system to modulate the wheel speeds to maintain traction and stability. That code can be caused by either a bad speed sensor or the wiring harness for it. The speedometer acting strange also says it is a real failure. To verify which sensor has the issue use a scan tool with live data to watch the output speed sensor while driving. If you see it drop out then you have the culprit.

I pulled the plugs off the sensors and probed the two leads coming from each.. Left front i could not get a reading at all like it was dead. (No good )

You won't get a reading from them unless they are connected and the vehicle is in motion.
The sensor that is causing the problem should be the one mounted in the transmission, not the ABS wheel speed sensors. That is why you need the scan tool to allow you to read live data from the 4 ABS sensors and compare those to the output speed sensor in the transmission.

Any idea where about this sensor is located? Its a 4.7 ltr v8 4x4 I know there are two. Would like to inspect before paying the dealer costs.

Both of the sensors are on the side of the transmission toward the top of the case about halfway back. The SP2 is the one monitored but they are both the same part number.
Bolt is torqued to 48 inch pounds. They are a simple coil sensor so just measuring them both with an ohmmeter should tell yo if one has failed. I would look close at the connector as it is easy for water to get in and corrode the pins.

Drivers side correct ?

Having a hard time finding the sp2 sensor. Added a photo of similar tranny. Is it more top towards shifter lever ?

You may have the later version that has one on each side. There will be one to the front drivers side that measures the input shaft speed and one toward the rear passengers side that reads the output shaft speed if it is the later transmission. The second one is the problem on your vehicle.

That's what i saw when i was under the vehicle. So in this case it is still same part number for both? Will dig into it again after work. Thank you..

That's what they show, Part # 8941332010 supersedes to #8941332011
The really weird part is the price ranges on that part. Toyota gets $158.00 for it but I see the same part number listed for under $20.00 at rockauto !

Same here. I ordered one from my hometown Napa store. Will be here in the morning. $24.97 Thank you again. Will update as to what i find.

I also removed the battery cables to try to reset everything. Little did i know i have to reset everything, lol. windows/key fob.. I love Lexus. lol

35000-60A60 is number on sticker on transmission from what i can read. Also i would assume this is the culprit on passenger side ?

Yeah, that is one of the reasons I don't tell people to try to clear codes that way. You are lucky, some of the newer Toyota and Lexus cars will lock you out if the battery is disconnected, the immobilizer trips and you need a dealer code and tool to reset it.

That is the part. The passenger side is the one that is your issue. I would check the wiring from the sensor up as the way it is acting is a bad harness. There are a few numbers depending on which of the brands you search under.

should i get any readings at the connector at the sensor? key on/ key off ?

The green wire is the sensor ground, The red wire is sensor bias voltage. So either 12 or 5 volts on the red wire when referenced to ground with the key on.

red was 1 volt. Green i got nothing grounded to frame ..

i used a better tester and i checked both leads coming into both sensors. I have 1.2 volts at both and no ground to either. My friend is a Toyota tech so i guess its time to drop it off. May be beyond what i can do unless you have more ideas. Too hard to follow leads from under the truck with very limited space.

he is not a Lexus guy so he said it may take a while to figure it out.

Sounds like a wiring issue, hopefully he has access to better information than what they give the aftermarket. Please let us know what he finds. It may help someone else, and thank you for using 2CarPros.

Well, my friend finally caved and had me bring it to the Toyota garage he works at. Found no problems with cluster or electrical. Did find if you removed one ABS sensor from the rear the speedometer works. If two removed it will not. He then found the right rear wheel seal has failed and allowed moisture to get in and screwed with the abs tone ring and whatever else is in that area. He was able to clean it all out and got speedometer working again but recommends i replace both wheel bearings and seals. He has had it for 5 days and is still playing with it to figure it all out. Said all those lights on dash wont go away until the ABS sensor issue is resolved. Most likely after the new components in the rear end. The PO500 code is gone with speedometer working . Will update some more as we figure it out. On another note truck wont last too much longer as it has the dreaded Toyota rust. Truck looks like new but frame is almost toast. Can make an engine that can last 500,000 miles but cant figure out rust. What a shame.

That frame rust is one of the biggest problems with them. The stuff they sprayed them with just hid the rust and made them rot even faster. I have replaced a few frames over the years, even went to salvage yards and bought ones that were damaged at each end, cut them and welded them into a good frame. Strip off all the coating and then apply woolwax to seal the metal. That could be an option if you like the truck enough. Sounds like the speedometer issue was that the bad sensor was taking the signal buss lines down, basically shorting them out. Please keep us in the loop and thank you for using 2CarPros.

Code C1238, foreign object is attached on tip of rear speed sensor. Never quite figured it out what the substance was. Looked like rubber pigeon crap. Cleaned it all up no dash lights or codes. Test drove 60 miles. All is good. Told to keep an eye and ear and if needed will replace bearings and seals. All is good now. Did find the gas tank is sitting on top of the cradle as the straps have failed from rust and corrosion. Replacing next week.

Hmm, that's different. Wonder if it is a dried grease or similar? Good you caught the tank, sounds like the rust is growing fast though. You might want to try giving it a coating of krown or woolwax, about $175.00 and might get you an extra year or two before it's completely shot. It soaks into rust and slows it a lot.