I will certainly let you know how it goes. Thanks for taking the time to share, much appreciated.

Sorry for hacking this thread. Anyone on here remember that guy that thought multiple lights on the dash and reading codes was a conspiracy? I was trying to show that one to a buddy and saw this one to check. It was hilarious. Anyway, if someone bookmarked it that would be awesome if you could share. Thanks in advance.

2007 4 runner sr5, 140k. CEL VSC TRAC lights on. Replaced gas cap with genuine toyota one, cleared codes. Lights came back.

Any guidance on where to start would be appreciated

Absolutely fantastic info about CEL (CHECK ENGINE LIGHT) codes. I had a P0442 and some others about a EVAP leak (VERY SMALL).
I tried 3 different gas caps and 5 different O-Rings. Reset the CEL light. But the codes came back within 50 to 95 miles.
THE REAL PROBLEM WAS A CRACKED HOSE. See pictures.
2004 SR5 V6. The hose is on drivers side between master cylinder reservoir and oil fill cap. Very hard to see crack. It was facing the engine. $1.00 piece of vacuum hose. No codes for 2000+ miles.

Attached Images

       

Have an '08 SR5 4.0L V6. 160k miles. About a week ago the CEL, TRAK, and VSC all lit up. Being that I had replaced the gas cap a few years ago with an aftermarket one, I immediately got an OEM one and replaced it Sunday. Drove it until today when I had some time to do some troubleshooting. Lights remain lit. Went to Advance Autoparts and had them pull the codes:
C1201 Engine Control System Malfunction (Current)
C1223 Malfunction in Antilock Brake System Control System (Current)
C1249 Open Circuit in Stop Light Switch Circuit (Current)
P0456 Evaporative Emission System Leak Detected (Very Small Leak) (Current)
P0456 Evaporative Emission System Leak Detected (Very Small Leak) (Confirmed)

I went forward and disconnected the neg lead from the battery for a few minutes and reconnected. All lights are now off, but waiting to see if they pop back up again. I will note that this is my daughter's vehicle, and she has been seeing the TRAC and VSC intermittently pop up and then go back off, with no apparent reason. Also, the TPMS light has been off and on lately as reported by her, but as I drove it today, I noticed it came on blinking for 1 minute, then illuminated for a period of time, then went out (so that tells me I have a TPMS sensor going bad or the battery dying--it has been 15 years, so...). I have an appointment to have these looked at/replaced on Saturday. Any other collective thoughts on the warning lights?

BTW, this forum is immeasurably helpful. Thank you.

Big thanks to the OP! I took the suggestion & ran down to the auto parts store for the free scan. Here are the results:

PO455 - Evap Emission Control System Leak (Gross Leak) - DTC Severity 1 of 3
PO455 - System Leak Detected (Gross Leak) - DTC Severity 1 of 3
PO455 - DTC Severity 1 of 3 - "Service should be scheduled & repaired when convenient. This DTC typically has no immediate threat to essential system."

Gas cap seemed loose so I tightened & will have the wife drive it for a few days to see if lights go off. If not, my plan is to replace the gas cap. If that doesn't work the last step is to take to a mechanic.

Does this game plan sound reasonable or should I consider a different plan of action? Thanks!

Very helpful, now I can get rid of those annoying lights on my dash.

Thankas for the info - i just had to jump start my 4runner and when it started up I saw something I hadn't seen before.

The CEL was flashing and the vcs off, trac off, slip indicator were solid - this was only for 15 seconds then they all went away. Any advice? thanks for all that you do in this community

So I just did my alternator & battery (remanufactured oem denso alternator & costco battery) after my alternator went out. After that I got the brakes & rotors done by a local shop. Once I got it back I drove for about 30 miles then the lights came on (VSC off, trac & check engine)

I got the codes checked and I have P0430, C1201, C1223 & C1241

Any idea what this could mean? Could any of this have been caused by the shop that did the brakes?

Any advice is greatly appreciated!

Attached Images

 

I'd clear the codes and monitor it. Some of the C codes could be from when you had alternator/battery issues. The P0430 is pretty common on a high mileage Toyota, could be from weak cats, leaky exhaust or lower o2 sensor.

Just for reference my 4runner has 137k miles with the 4.7L V8

I did clear the codes right away, and they came right back up after driving about 30 miles again… Sounds like I may need to do a cat delete if thats causing some of this 🤣

I may bring it back to that shop and see if they have any ideas. I just dont want to start blindly replacing parts if it’s not needed. Sounds like there may be fuses that can cause some of this too? I’ll take a look at that tomorrow as well, but if you have any advice on what to look for itd be greatly appreciated!

There's a ton of threads for the p0430 code. The downstream sensors work a bit differently than the upstream ones but I think you can still check that you are getting voltage on the O2 heater wires. The C codes are an unknown to me and I'm not sure if they clear the same way.

When no issues with the circuitry, some folks put spark plug non-foulers between the sensor and cat to skew the numbers slightly. I've had the low efficiency code go away by putting better quality fuel or higher octane, gets me through state inspection.

I tried Cat Clean, and higher octane fuel. Sadly now I have both P0430 & P0420 codes among the others. Guess I should take it to the shop

Is the forum weird for anyone else?

Anyway, here's where I am in my own VCS/TRAC/ABS dash light saga;
My Dastardly 3 lights are on with the Brake light but NOT the CEL. Several years ago I had the ABS codes scanned and it indicated the right rear wheel sensor which I replaced, lights did not go away at that time but I lived in FL with no vehicle inspections so I just left it alone. Fast forward to now, I live in TX and I need to get this truck through an inspection annually. I have replaced the fuel cap (which I believe is more of a CEL-related problem) which did nothing. I replaced the brake light switch, no improvement. I am up against a clock now so I pulled both rear sensors off and unplugged the wiring harness from the connector above the rear diff. Sprayed electronic cleaner on everything, tested continuity between the ends and the plug and everything checked out. Added some dielectric grease and plugged everything back in. I also cleaned off the sensors and sprayed some brake cleaner down in the sensor hole hoping the maybe clear anything that might be on the reluctor/pickup. No improvement after all of this. I did notice that the right side rear hub has a definite layer of oily muck on it, much more so than the left side. I had a bad wheel bearing on that side that I had replaced back in 2021 so I am hoping that that is just residual muck buildup. Did a Zero Point Calibration and this cleared the lights long enough for me to make it out of my driveway at which point they all came back on again.
I finally invested in a good OBDII reader and hooked it up, I am pulling 3 codes C0210 (Rear Speed Sensor RH Circuit), C1223 (ABS Control System Malfunction), C1336 Zero Point Calibration of Deceleration Sensor Undone. I can clear these with my reader but they all come back on after a very short drive. I am hoping that there is something in the harness between the plug above the rear diff and the ABS module itself and will have to crawl back underneath it to do some testing.
Questions;
1. Would the failed right rear wheel bearing and differential fluid leak have damaged the sensor or the pickup? I had replaced the sensor on this wheel prior to having the bearing & seal replaced.
2. What kind of voltage readings should I be seeing at this plug?

I can't really help you with your issues other than to say that "dielectric grease" is non conductive and should only be use to help keep water/dirt etc. out of electrical connections, if the dielectric grease is on the actual contact areas of the electrical connection it could cause a bad connection.