VSC & Trac Off light ON 2002 4Runner

[xcmountain80]

I'm on the road and can't remember for the life of me what is associated with these lights. This is a 2002 4Runner, Auto transmission 4Wd. I'm on the 3rd or 4th gas cap in 2 years, just replaced the Air Fuel Sensor (mounted up stream of the cats). No CEL, or ABS lights to accompany the other two. Thoughts?

Thanks

Aaron

 

[Xinirgi]

You don't have the center diff locked do you?

 

[MStudt]

You don't have the center diff locked do you?

and in 4x4 for this to happen. The CDL button is a momentary button. You push it to lock it and push it again to unlock it. When you cut the 4runner off, it resets itself back to off. So this wouldn't be it, unless there is something wrong with the sensor.

 

[Auce]

Is the check engine light on also? Could be a bad o2 sensor?

 

[xcmountain80]

You don't have the center diff locked do you?

No, this is while in normal 2wd operation.

 

[xcmountain80]

Is the check engine light on also? Could be a bad o2 sensor?

No that's why it wasn't mentioned in the title or the original post. If I had a CEL then I'd have a code and an answer .... Sort of.

This has been bothering me for some time. I did have a CEL last week and that's why I replaced the Air/Fuel sensor (located upstream of the cat). Have a URD O2 simulator hooked to the rear so very unlikely it's that, and it would throw a code.

 

[MStudt]

No, this is while in normal 2wd operation.

Even if it were in 4wd it wouldn't be the CDL. It resets once the car is turned off.

No that's why it wasn't mentioned in the title or the original post. If I had a CEL then I'd have a code and an answer .... Sort of.

This has been bothering me for some time. I did have a CEL last week and that's why I replaced the Air/Fuel sensor (located upstream of the cat). Have a URD O2 simulator hooked to the rear so very unlikely it's that, and it would throw a code.

Did you clear the code? What was the code when the CEL was on? A lot depends on what code you had.

O2 sensors don't always through codes. It could be an ABS sensor, could of had 2 bad O2 sensors, cats could be bad (not as likely), or bad gas cap. Kind of hard to tell you with knowing the code.

 

[xcmountain80]

The code was a 1135, almost 100% typical of a front Air Fuel sensor. Cat is a flow through and there is only 1 and not 2 like the original setup. A full exhaust system was made last year.... Headers, hi-flow cat, muffler. I know that these lights are tied to the emissions system and are generally the precursor to a CEL. But this will stay off for a while after a new gas cap. I'm wondering if maybe I should have the system smoke tested and see what's up and if they are any leaks....maybe at the gas cap?

 

[MStudt]

The code was a 1135, almost 100% typical of a front Air Fuel sensor. Cat is a flow through and there is only 1 and not 2 like the original setup. A full exhaust system was made last year.... Headers, hi-flow cat, muffler. I know that these lights are tied to the emissions system and are generally the precursor to a CEL. But this will stay off for a while after a new gas cap. I'm wondering if maybe I should have the system smoke tested and see what's up and if they are any leaks....maybe at the gas cap?

You can smoke check it yourself and save about $500. I did it a couple years back on my F150 to find a leak, not to hard either, and a perfect reason for needing a cigar.

 

[xcmountain80]

You can smoke check it yourself and save about $500. I did it a couple years back on my F150 to find a leak, not to hard either, and a perfect reason for needing a cigar.

Hmmm, didn't know I could do it myself. It ran me $79 last time (1-shop hour), when playing with the charcoal filter. How does the smoke test work, is it a pressurized introduction of smoke to the fuel and emissions vacuum system?

Thank you

Aaron

 

[BlackWorksInc]

Is just the VSC & Trac lights on and no MIL? Some of those 3rd Gens run the HydraBoost unit the 4th and 5th Gens have.

 

[xcmountain80]

Is just the VSC & Trac lights on and no MIL? Some of those 3rd Gens run the HydraBoost unit the 4th and 5th Gens have.

Hydraboost, that's a new one to me. Tell me more!

 

[BlackWorksInc]

Hydraboost, that's a new one to me. Tell me more!

I may have accidentally coined that term myself to be honest with you. I think I had one of the Toyota Factory guys refer to it as a "Hydraboost" a long while ago and I used it (I believe Cadillac actually used the term for a similar system on some of their older vehicles.)

I think Toyota refers to it as a "Hydraulically Assisted Master Cylinder Assembly," thus the short-hand "Hydraboost" is much easier to remember. Though I don't think I've seen any official Toyota documentation stating it as an "official" term. So... my bad?

Entomology aside, its basically what the 4th & 5th gens use in place of a standard vacuum booster assembly. Its a combination Master Cylinder, ABS Module, ABS Solenoid Pack, Hydraulic Accumulator Tank, and Hydraulic Motor (to generate pressure) Some 3rd gens (which I found out recently, I think mainly the '00+ models) came equipped with them, a common issue 4th gen 4Runners from '03-'04 have is that low battery voltage erases the ZPC (Zero Point Calibration) and thus those two lights may be set (not always accompanied by a MIL on.) The DTC for this will not show up on typical code readers because it is stored in the ABS/VSC/TRAC module. Though I've never worked on one with this system, but I assume the process will be similar.

Here's what it looks like:

 

[SilverBullet01]

i have this exact same issue with my 4runner for about three years now.... doesnt come on right away. the car needs to warm up. sounds like my diff engages itself.

 

[BlackWorksInc]

I will see if the ZPC learning procedure is the same for the 3rd gens, you guys with these units may benefit from it.

 

[xcmountain80]

I will see if the ZPC learning procedure is the same for the 3rd gens, you guys with these units may benefit from it.

Yes that's what my brake device looms like. And yes I read a thread for the 4th and 5th 4R's, as how to go about altering a OBDII reader to to something fancy and magic.

According to what I read the symptoms sounds exactly the same, well there are no real symptoms other than lights on. Some experienced decreased braking performance, but mine will throw you into the dash (Tundra 231mm).

Now all this aside I did the gray wire mods years ago and wonder if that has anything to do with this. It still works as it is supposed to no question.

Thank you

 

[BlackWorksInc]

Yes that's what my brake device looms like. And yes I read a thread for the 4th and 5th 4R's, as how to go about altering a OBDII reader to to something fancy and magic.

According to what I read the symptoms sounds exactly the same, well there are no real symptoms other than lights on. Some experienced decreased braking performance, but mine will throw you into the dash (Tundra 231mm).

Now all this aside I did the gray wire mods years ago and wonder if that has anything to do with this. It still works as it is supposed to no question.

Thank you

If the ZPC calibration is off then the system may still function properly but use a default set of data points (I think if I remember correctly...) I didn't get the chance to look up the procedure for your vehicle yet. Was busy most of the day and did some overtime so I didn't get the opportunity to look.

 

[xcmountain80]

The zero point calibration for a 2005 sounds interesting. There was a thread I read with a shade tree mechanic approach to resetting the VSC computer. There was a FSB link in the post and mention of wing able to to the procedure with a OBDII el cheapo and a home made SST that consisted of some jumper wires.

 

[quicksilvr]

The VSC and TRAC OFF lights would be on constantly in my 2001...if I hadn't removed the bulbs. Mine go on about 5-7 seconds after starting the truck, and it's because I have LED bulbs in the dash and other places. The resistance isn't the same as what the truck is expecting to find when it does a system voltage/electrical check right after start up, so it disables VSC and TRAC.

I personally like having them always disabled, so I just pulled the bulbs out and forgot about it.

 

[xcmountain80]

I did the zero point calibration and much to my surprise it worked for a while, that is until you put the 4Runner into a corner, and I'm guessing the yaw sensor goes crazy and triggers the light. It resets every time I turn the truck on now and the lights stay off until a corner comes up.