2020 SR5 Premium with rough, shaking idle at start and check engine light

It isn't just Toyota.

Honda uses soy based wire insulation as well. The two most reliable car companies in the world.

I'd be willing to bet this isn't a very big issue for either of them, tbh. Probably only happens to a small percentage of their vehicles and they don't have to pay for it, so why bother changing anything?

If people stop buying their vehicles because of it, then they would address it promptly, I'm sure.

But are people going to run out and buy a Jeep and then have to deal with a bunch of Jeep problems because a mouse could potentially chew on some Toyota wires? Probably not.

My guess is people would rather deal with the mice than deal with a Jeep

 

It’s not just Toyota.

https://www.caranddriver.com/news/a21933466/does-your-car-have-wiring-that-rodents-think-is-tasty/

 

I put rat wire on the engine air box intake .. not just on my Toyota runner... all my vehicles I did this ..
back in the early 1980's I was driving to work in my 1983 GM sedan.. check eng light came on .. I saw some crap around my intake manifold and then I took off the metal air cleaner cover off and the carb air filter was loaded with rodent nest crap.. so that is why I do this over the decades using 1/4in steel galv wire screen..
so last week I took out 4 rodents ,, they are all eaten up buy the predators...

 

Thanks everyone for this thread! I had the same issue. A couple months ago, I took my 2018 4 runner in for service and upon leaving, they told me "your cabin air filter is dirty, you might want to change it soon". I remembered to check it about a week later, and noticed it had been almost chewed completely through by a rat or mouse. There were rodent turds all over in the grooves in the filter. Pretty sure the dealership should have changed it, or asked me if they should change it. Regardless. I changed it. And noticed a couple weeks later there was a nest in the engine bay that appeared to be made of the air filter bits. I removed it. Yesterday (about another two weeks later) I started the rig and noticed a wobble coming from the front, and the CEL was on, as was the Multi-terrain select warning light. I looked in the owners manual and it said to call the dealership, which I did, but no answer, so left a message. (Fucking dealership). So, I started doing research and found this thread. After reading, I went out and checked the engine bay again. And sure enough, right where I had removed the next, the wiring harness (I believe injector wires) were chewed through. Not sure if the rodents came back for more, of if the damage was done and it just finally worked it's way loose. Regardless... Luckily there was enough wire left that I could cut and splice in new wire and didn't have to go to the dealership for repairs. I still need to get the warnings cleared, but the wobble is gone and things seem to be working right. See pics for before and after...

 

Rodents will chew all types of cars. Never heard of the electrical wires though. I was camping once and two nights in a row a kangaroo mouse ate some fruit in the car. Better than wires though

 

I use cheap and effective glue traps around the perimeter of the inside of my garage, it works. I get mice and these blue skinks we have here in Tennessee.

 

I park out in the front of my house in San Francisco, and we have the standard city rats that come out at night. No stopping them. But what I hear is that Toyota actually uses a wire coating made of soy, which the rodents love. Gonna cover the new wires (which aren't coated with rat food) with plastic and hopefully that helps. But, they chewed through the original plastic wire covers too.

 

A neighbor and I use a light spray of peppermint oil in the engine compartment to prevent this. So far it works...

 

Does anyone know of any other potential causes of this issue? Our SR5 just did this on initial startup this morning. However after shutting it off and restarting it, it went away. It didn't come back on a second startup either.

It just had the 10k service done at the dealership and had been filled up since then, but that's it. It drove home from the dealership and gas station just fine.

 

Mice and rodents have been chewing wires since long before soy based wire insulation was a thing.

 

CaLRnr ,, This happened to me this weekend. I was out of town in beach vacation and there was a storm so we did not drive the car for couple days. Next trip to out noticed the vibration and light. I thought it was the gas cap coz I did fill up couple days ago. Then neighbor mentioned something about rodents chewing wires so I popped the cover and saw 1 wire was completely gone. I thought about dropping it at a local shop but I know they don't stock parts so decided to order it myself from NAPA took about 2 days to get it and just connected it. The vibration is all gone but how do you get rid of the lights??? Do I need to disconnect the battery or use the ODBII devices to reset???

 

go to a auto part store autozone or advanced auto... use the code reader tool to see if the codes are in the system .. copy the codes then reset the codes .. see if it works good.. post if your codes are in the forum ... ..probably a wire will get replaced easy but if the connectors are chewed up it is a part ..on the injectors ?

 

Or, just piss on your wires. I guess that probably doesn't sound too good. I left my side x side sitting on the ground for a couple of weeks while I was working on the trailer and the little critters did indeed eat through my injector harness.

 

Is it really soy?
https://www.4runners.com/threads/soy-based-auto-wiring-a-myth.22586/#post-287006