Why Your 4runner VSC, Trac, ABS Lights Come On (Without CEL)

Nearly 5 years ago, I wrote an article about my 4runner’s gauges being lit up like a Christmas tree. Well, Santa is back, my friends – but this time, there’s no angel on the tree. The Check Engine Light is not present.

I started it up the other day and noticed the red ABS light, and all of the VSC/Traction related lights were illuminated. Seeing so many warning lights come on in the dash might be unsettling for a novice 4runner owner, but it didn’t surprise me.

You see, these 4th gen 4runners do a great job of letting you know when they have a problem. The issue is that rather than whisper it in your ear, they like to blast it through a megaphone.

As I mentioned in the original article, the VSC and Traction Control lights often turn on when the Check Engine light is triggered. Toyota doesn’t want you to be able to ignore one bulb – they light the whole dash up to get your attention.

In this case, it’s very important to note that I did not have a check engine light illuminated. The lights were strictly traction, ABS, and VSC related. If you’ve come to this article because the lights are on in your 4runner, make sure to head over to my other post if your check engine light is also on. That’s a totally different situation.

Investigating the reason for VSC, ABS, and Traction Control lights in your 4runner

There are a few potential causes for these lights to come on in your dash. 2 of them are easy fixes. The others – well, maybe not so much. The good news is that the easy ones seem to be the most common though.

You can attempt to scan for diagnostic trouble codes if you happen to have a code reader that also reads the ABS system. Many of the cheaper scan tools will not. 

I didn’t have one, and chances are, it would probably just say something like “ABS system error” or something that doesn’t really help me to pinpoint the problem anyways.

With that said, it’s totally worth it to borrow a scanner from the parts store or even take it in to a shop to have the codes read before you start throwing money at the problem. After doing some research on the T4R.org forums, I was fairly confident in what the problem was so I skipped this.

Potential causes for VSC, ABS, and Traction Control lights in your 4runner

The two most common reasons for these lights to come on are surprisingly cheap and easy to fix. If you’re handy at all, you should be able to do this yourself.

Faulty Stop Light Switch

That’s right, all of those scary lights can be caused by something as simple as a switch that’s connected to your brake pedal. This is what caused my issue.

When you push the brake pedal down, it activates a switch that tells your 4runner’s brake lights to come on. This switch can get worn out, dirty, or contaminated over time and the ECU might notice that it’s not receiving the signals it’s supposed to.

If that’s the case, it will trigger these warning lights in the dash. I guess technically, it’s related to the ABS system but I’m not sure why it deactivates the VSC and traction control (and yes, after some winter driving, I confirmed that these systems are indeed turned off – that’s why the lights are on).

It seems as though the best way to confirm your problem is caused by a brake light switch and not a zero point calibration is if the lights only come on sometimes but not all the time. They’ll also come on whether you’re driving or in park.

In more serious cases where there’s a chance that the brake lights could be malfunctioning, your 4runner is smart enough to lock itself in park so you’re unable to drive unsafely. If you’ve confirmed that your lights are working so you can at least get home, you can bypass the lockout by popping the cap next to the shifter off and pushing the button to shift it out of park.

Don’t do this if you think your brake lights aren’t working though! Causing an accident isn’t worth saving the money from a towing bill.

A replacement stop light switch is cheap and easy to replace. You can either get one from the Toyota dealership (part number 8434069025) or find an aftermarket one online or at a parts store. 

I went with this aftermarket one from Beck Arnley (part number 201-2337) but if I were to do it again, I’d just get an OEM one from Toyota. This aftermarket one didn’t quite fit right and I had to swap the internals of the new switch into the old one. 

In the video below, I show you how easy it is to unplug the stop light switch, pull the old one out, and pop the new one in.

Lost Zero Point Calibration

Our 4runners can lose their zero point calibration for a few reasons. It might happen if you’ve had the battery disconnected for an extended period of time, you’ve modified your suspension, or you’ve had a wheel alignment done. 

It seems as though the most common cause for a lost zero point calibration is by using a newer code reader on a 2003/2004 model 4runner. Apparently, Toyota changed from the ISO to CAN protocol somewhere around 2005. If your code reader tries to communicate using the newer CAN protocol with an older 4runner, it can erase the zero point calibration from its memory.

The 4runner uses this “zero point” reading to compare with the readings the Yaw-rate and Deceleration sensors are sending. If it thinks something is abnormal (like the vehicle has flipped over), it’ll cut power to the engine for safety. When your warning lights come on, your 4runner is basically telling you that it doesn’t know if things are normal or not.

Thanks to user MicaBlue03 on the T4R.org forums for sharing information on this!

If your 4runner requires a zero point calibration, the Vsc Off and Trac Off lights will come on every time you start your engine, put it in gear, and begin driving. The ABS lights may or may not come on as well. Unlike the stop light switch, they will not be triggered while the vehicle is idling in Park.

A Toyota dealership might tell you that the only way to recalibrate this is with their fancy Techstream computer. That’s one way to do it, but you can also go the DIY route if you’d like to save some money.

How to perform a Zero Point Calibration for a 4th gen 4runner:

Warning: If you aren’t confident in your abilities to follow directions, leave this to a professional. Accidentally shorting the wrong connections can cause damage to your 4runner

You can perform a zero point calibration without any tools (aside from a piece of wire). It’s simply a matter of jumping two connections in the OBD2 port together in a certain sequence.

The zero point calibration must be done with the vehicle on level ground, without bumping/shaking the vehicle, and without starting the engine.

Step 1: Locate the OBD2 port

This is where you would connect a diagnostic code reader under your dash. It might have a black cover over the connection that reads “OBD” on it. If so, pop the cap off.

Step 2: Turn the ignition on

Make sure the transmission is in Park and you do not start the engine.

Step 3: Locate the Ts and CG terminals in the connector

The Ts should be the 3rd from the left in the top row and the CG should be 5th from the left in the bottom row.

Step 4: Jump Ts and CG together

With the ignition still on, use a wire to connect the Ts and CG together – tap it 4 times within 8 seconds. The VSC light should be illuminated, meaning that the zero point calibration has been cleared.

Step 5: Turn the ignition off

Once you’ve confirmed the VSC light is on, you can disconnect the wires and turn the ignition off.

Step 6: Turn the ignition on

The VSC light should turn off within 15 seconds

Step 7: Once the VSC light is off, turn the ignition back off

The VSC light should stay off for at least 2 seconds

Step 8: Connect the terminals again and turn ignition on

The VSC light should turn on for 4 seconds then start blinking quickly.

Step 9: Once the VSC light has been blinking for 2 seconds, turn the ignition off

Your zero point calibration has now been reset. Confirm the lights don’t come back on after driving!

Low brake fluid

Your red ABS light can be triggered if brake fluid in the reservoir is running low. I’m not sure if the yellow VSC and Traction lights would be lit in this case, but it wouldn’t surprise me. 

I do know that if your brake fluid is dangerously low or the system senses a leak, there will also be a loud buzzing sound from the dash. If that happens, do not attempt to drive your 4runner – it likely has a catastrophic failure in the brake system (in my case, it was a blown brake line).

If your fluid is only a little too low though, you might end up with just the light in the dash trying to catch your attention. 

Faulty ABS Wheel Speed Sensor

It’s possible that the ABS sensor on the hub can be worn out or broken. This is even more possible if you do a lot of off-roading and the sensor may have been snagged or smacked by something you’ve driven over.

This should throw a diagnostic trouble code that you can read with an OBD2 scanner, as long as it shows ABS codes and not just Check Engine Light ones.

Conclusion

I’ve seen people give advice online that a new gas cap will fix these lights but that is untrue. If your gas cap is the problem, it will register a code for an evap system leak and trigger the check engine light. This article is only useful if you do NOT have a check engine light illuminated – just the VSC, Trac, and ABS lights.