VSC, TRAC, and Check engine lights on

[taras91]

And the Verdict is:

Oxygen sensor in back of one of the cats. Tech showed me the code on their computer when he plugged it into my 4Runner.

This is how the tech explained (and showed me) how this works. 4Runner has 4 Oxygen sensors (1 on either side of each Cat). Engine side sensor monitors "dirty air", muffler side sensor monitors "clean air". If either sensor (or either side) fails, it throws the CEL. Makes sense to this point, right? On 2004+ models (and if you had the Sulfur TSB), if the CEL is lit, it also DISABLES the VSC/TRAC systems.



So I asked the question, why disable these systems if the CEL is lit? He said he did not have a direct answer but basically Toyota thought if the CEL light was on, any system that directly put a load on the engine that wasn't necessary should be disabled (which also means that the DAC might also not work) to prevent further damage to the engine. Since the VSC/TRAC works in conjunction with the brakes which can add a load to the engine, this system is disabled.

I asked one more question (for all you modification happy people who don't like VSC). Can I purposefully disable the VSC? No (officially). (unofficially you could throw a switch on the wire from one of the sensors to spoof the computer to think the sensor failed - since this would force a CEL condition, VSC would be disabled).

THANK YOU. I am currently dealing with CEL and high fuel trips. I ordered new o2 sensors. Hopefully it fixes my issues and vsc/trc turns off like it did for you. THANKS

 

[taras91]

Im having same issue. Im replacing my OT sensors to fix this. FREEZE frame data shows a P0171 code when all the lights come on.

 

[djakpr28]

sunroof noise

i have a 2005 4Runner SR 5 and about a week ago it look like noise coming from the sunroof is like a wind noise and also it feel the sunroof vibrating these no water coming from the sunroof just the wind noise,can any person know what can cause this problem Than you

 

[djakpr28]

VSC Track light

Also my VSC TRAC LIGHT are on i did buy one new cap from the dealer but lights is still on can someone can help me

 

[mr2t_]

I have an 05 v8 Limited I've been having a strange cel w/ traction lights issue for a few years. It seems like the lights come on during the cold season (Nov/Dec) and go away when it warms up around March. I tried a new gas cap the first spring and it went away after a few starts but I can't tell if it was the warmer weather. This winter I had the light until a few weeks ago then when I filled my gas tank the lights went off instantly. I got the codes checked previously and it says brake master cylinder and some engine code. The brakes work totally fine and the engine runs great with or without the lights on. Anything weather or gas tank related that could cause the cel?

 

[Moist]

Just got all three. Freaked me out. Gas cap is on tight, and in good condition.
Just got my oil changed about a month ago. Also went from 91 gas to 87.
Installed new parking lights and had to disconnect the battery. Had a poor connection the first install, and I drained the battery good. Second time around it's perfectly fine. Idling anywhere around 1,100 to 500 RPM. (Prly just the wild temp changes we're having here though)
Couldn't tell you if it was making any weird sounds, thing's always making a racket driving down the road.
No OBD reader tho, gotta bring it in.

 

[AuSeeker]

Just got all three. Freaked me out. Gas cap is on tight, and in good condition.
Just got my oil changed about a month ago. Also went from 91 gas to 87.
Installed new parking lights and had to disconnect the battery. Had a poor connection the first install, and I drained the battery good. Second time around it's perfectly fine. Idling anywhere around 1,100 to 500 RPM. (Prly just the wild temp changes we're having here though)
Couldn't tell you if it was making any weird sounds, thing's always making a racket driving down the road.
No OBD reader tho, gotta bring it in.

Most all auto parts stores will read the codes for free.

 

[Moist]

Most all auto parts stores will read the codes for free.

Noted for the future. Already scheduled the appointment though, will report back on what it turned out to be.

 

[Moist]

Noted for the future. Already scheduled the appointment though, will report back on what it turned out to be.

It turned out to be a bad gas cap & old spark plugs

 

[Ethanqbs]

First of all thank you everyone from this forum and this thread. New owner of a 2004 SR5 v6 4runner at 286k miles. Last night, after I filled the tank I got everyone favorite 3 lights on, CEL, VSC, and TRAC. I googled and found this forum, this thread. Read all 10 pages, so I tried the small step first, the gas cap. This morning, went to Autozone and got a new gas cap $16.99. Disconnected the battery, replaced the gas cap. Reconnected the battery, and went for 34 miles drive to see if the lights are coming back. None so far, knock on wood. Thank you again.