Code P0500, check engine light for vehicle speed sensor

2013 TOYOTA HIGHLANDER

104,000 MILES • V6 • 4WD • AUTOMATIC

LEXIEPAX06

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I recently installed an aftermarket radio into my vehicle listed above (SE model) using a plug-and-play harness. Shortly after installing, the engine light came on. The speedometer and tachometer are working perfectly fine, and the car seems to be running fine as well, but my cruise control won't work or even turn on. The only thing I could think of was that something must've shorted when I installed the radio. I took it to a local car shop that I trust and after spending $400.00, they could not figure out what is causing the engine light to come on. The error code is pretty consistent -- P0500. I did buy the vehicle speed sensor part online and gave it to them. They said they replaced the old one and the light still comes on. They said they didn't see any physical damage to the wires either. The last thing they also said, when they removed the sensor, the engine light turned off, but then the vehicle won't shift properly. When they put the sensor back on, obviously, the engine light came back on but the car drives and shifts normally. They tried to take apart the center console to check for the computer module but they said they didn't find one in my car, so they just ended the search from there as my bill was climbing with no solution in sight.

I am at a loss. I don't want to take my car to the Toyota dealer and have them tell me the same thing or even send me a higher bill for parts that I don't need. I was wondering if you guys can share anything that you might suggest I should do. If I go have another mechanic take a look at it, what should I tell them to look or check for that the other mechanic hasn't done?

Thank you in advance.

Jul 24, 2021 at 3:30 PM

KASEKENNY

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Did you unplug the radio and clear the code to see if it comes back? More than likely this is causing the issue. If you take a look at the wiring diagram below you will see that the speed sensor is used for cruise control operation. So I suspect your cruise control is not working at this point.

If it is not then unplugging the radio will more than likely get it operating again. The wiring diagram on page 7 below shows that the radio system and speed sensor are on the same network that the speed sensor is on. This means when you plugged this aftermarket radio in, it is corrupting the bus communication for the radio to properly communicate with the other system. So the speed sensor is trying to send its signal to the body computer but it is not able to do that because the radio is disrupting this communication.

Here is a guide that will talk about this CAN bus network:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

If unplugging the radio and the code is able to be cleared then you will have to contact the radio supplier and ask if they have any solution for this.

Please let us know what you find with this. Thanks

Images (Click to enlarge)

Jul 25, 2021 at 2:47 PM

LEXIEPAX06

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5 POSTS

Thank you so much. I did unplug the radio and cleared the code. The engine light came back on after a few minutes. I even tried to reinstall the original radio, cleared the code and the engine light still comes back on. It sounds like plugging in the aftermarket radio caused the damage already.

Jul 25, 2021 at 4:28 PM

KASEKENNY

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18,907 POSTS

If that is the case, it could be a coincidence. Normally if this was the issue that the network was being corrupt then as soon as it is disconnected then the network clears up and the issue goes away.

So if this is still there then we have an actual fault and it is not the sensor if you replaced it.

I would suggest we run through this testing attached above and find out what it brings us to. It may be the ECM but let me know if you have questions as we work through this.

Jul 25, 2021 at 7:49 PM

LEXIEPAX06

MEMBER
5 POSTS

Thank you so much. This is very helpful. I did order an aftermarket version of the vehicle speed sensor, not a genuine Toyota part. I'm getting mixed advices also from different forums. Is it true that if the speedometer still works that the vehicle speed sensor is not the issue? I'm not sure of it's possible that the part I bought was no good, but then I would also don't want to buy the original part and find out it's not really the issue to begin with.

Jul 25, 2021 at 8:31 PM

KASEKENNY

CERTIFIED EXPERT
18,907 POSTS

Normally that is the case with a vehicle speed sensor on older vehicles. This is a common problem on forums as it is full of people that may not have correct info.

On more modern vehicles like yours the vehicle speed sensor is not used for such things as traction control, shifting, or ABS activation like it was on older vehicles.

So they are correct that on older vehicles when a speed sensor would fail, it would cause all sorts of issues with these other systems.

However, your vehicle is "smarter" than others and it can take the vehicle speed sensor data and compare it to the wheel speed from each wheel sensor. If it does not match then it will ignore the vehicle speed sensor for all these other functions. It will turn the check engine light on and most likely disable the cruise control.

I attached some info on this but I would suggest running through all the diag for that code as it may not be the sensor. Just because the sensor was not an OEM one does not mean it is the issue. It could be but I would suggest going through the testing before spending the money on another sensor just to find out that was not the issue.

Images (Click to enlarge)

Jul 26, 2021 at 11:07 AM

LEXIEPAX06

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5 POSTS

Wow, I couldn't thank you enough for taking the time to give me such detailed response. I will keep you posted. I will show the mechanic everything you showed me in this post, which will save all of us time from going around in circles in trying to diagnose and resolve the problem.

Jul 26, 2021 at 11:28 AM

KASEKENNY

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18,907 POSTS

You are more then welcome. We are curious as to what they find. Let us know what they find if they need help determining what the issue may be.

Thanks for using 2CarPros.

Jul 26, 2021 at 7:09 PM

DONBOYLES

MEMBER
3 POSTS

Wow. This exact thing just happened to me. 2013 Highlander with new after-market radio. Did anyone ever figure anything out?

Jan 6, 2022 at 2:04 PM

LEXIEPAX06

MEMBER
5 POSTS

I took my car to another mechanic and showed them everything from this post, but they are now asking me to go directly to Toyota because it's most likely electrical-related. I haven't had the chance to make an appointment because I contracted COVID and got hospitalized, and then the holidays happened. I still have the engine light on, but my car seems to still be running smoothly except without my cruise control.

Jan 6, 2022 at 2:14 PM

DONBOYLES

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3 POSTS

I was just looking on another forum and a guy with a 4Runner had the same problem. He cut the VSS wire on the OEM harness and it went away. I’m still researching.

Jan 6, 2022 at 2:17 PM

KASEKENNY

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18,907 POSTS

Thanks for your additions guys.

Please don't cut the speed sensor circuit. This is not a fix, and you are going to have other issues. If we have these codes, then we need to work through the testing to actually figure it out.

I understand there are people on forums that say they did something, and it fixed the issue, but they never come back and tell you all the other things that happened as a result of something like just cutting a wire.

We help all sorts of people on this site that buy a vehicle that has an issue and spend a lot of money and stress trying to figure it out, just to find out someone did something like this.

We are here to try and help you figure this out the right way and if there is a short cut repair that will solve the issue but not cause others then we are all for it. We just don't recommend doing things like this.

Thanks. Let us know how we can help walk through this.

Jan 6, 2022 at 5:20 PM

DONBOYLES

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3 POSTS

What do you recommend? On some vehicles, there is a feature that causes the radio to get louder as the speed increases. The theory is that an aftermarket radio might disrupt or distort that signal causing the PO500 code and the quick fix is to cut the wire since the signal isn’t being used as intended. What is the proper fix?

Jan 6, 2022 at 5:25 PM

KASEKENNY

CERTIFIED EXPERT
18,907 POSTS

Totally understand. If the issue is that the aftermarket radio is causing it then I would unplug the radio and clear the code.

Confirm that the radio is in fact causing the code because it does not come back.

If it is then you more than likely have a connector kit or jumper to connect your aftermarket radio to the OEM harness. At that point you want to make sure the connector on the jumper side of the connection does not have a wire in the speed sensor terminal. If it does, just remove this wire from the terminal. That way it is the same effect as cutting the wire as the circuit will be open. However, the OEM harness is left intact so if you ever sell it and someone puts the OEM radio back in, this function will work again.

If there is no jumper harness, then contact the radio supplier and see if they have a work around as their radio is causing the issue.

At the very least leave a note or something telling the next owner that you did this. Just think about how you would feel if you bought a vehicle, and something wasn't working, and you found that the previous owner just cut something. Those man-made issues are the hardest to find.

However, if the code returns with the radio unplugged then you have an issue with this circuit so the testing that I attached previously is what we need to do in order to figure out the issue.

I understand that this code could be caused by the aftermarket radio but that is not the only cause of this code.

Jan 6, 2022 at 5:42 PM