4HI and Slip Indicator

Hi all! First post here, so bare with me...

Bought a 2011 Tundra Crewmax TRD 4x4 with lift and 37's.

- The Slip Indicator (not VSC off) is on (steady state) and 4HI is flashing.

- I cannot switch into 4HI or 4LO.

- I hear/feel a slight chunk/grind noise (hard to explain) as I am completing my stop (doesn't seem like brake grinding - it's basically as the vehicle is at the 99% point of the stop). It may? feel a bit like the brakes are applying a fraction of a second early? Or the tires rotation has somehow stopped slightly early.

I know that big tires/etc. can sometimes lead to wheel rub. When I turn left, I get what feel/sounds like wheel run a decent way before maxing out the wheel. To the right, I don't really get much/any rub. Is there a reason on these trucks as to why you would get rub significantly earlier on one side vs the other? Could this be related to the issue in question? Perhaps some slip is being detected and the rotation is locked (and instead of run I'm getting wheel skip?).

I have tried shimming the yaw sensor, doing the vsc reset (with wire), disconnecting the battery, etc (in various orders). When I do the vsc reset, the Slip Indicator (already on) starts flashing, and does not go off. I turn the ignition off, jump the ports, turn the ignition on, and the Slip Indicator flashes a few times, and then off for a second, then a few flashes, off for a second. It just continues doing this but does not go off. When I turn the truck off and then back on (even with negative terminal disconnect in between) everything is the same as before (4HI flashing and Slip on solid).

When not doing the vsc reset, I do not have other lights on (no abs, no vsc off, etc.).

I do NOT notice any difference on inclines or declines, or when going around corners or on ramps at a decent speed.

I'm also getting about 11 mpg on the highway (I know tires/lift reduce that), and have read of people getting increases in mpg once the yaw sensor issues were resolved (so not sure if the mpg reduction is a symptom of this issue, as well).

I've checked for loose or broken wires and sensors, but haven't seen once I can correlate. That doesn't mean that there are none, though. I don't see anything that looks broken around/from the wheels. I do see some not connected cables about halfway down the truck, that are run through the undercarriage. I don't see how/where these would be connected. The previous owner had some extra stereo stuff implemented, and removed before I purchased, so not sure if it's related.

Also, I've read of some similar situations where the front actuator may have been the issue.

Any help would be great! Thanks.

 

Anybody?

Sorry to be impatient...but this has been an issue for a while now, and I've run into a wall with suggestions I can do myself.

 

Might be helpful to post some pictures of your suspension. What kind of lift do you have? Can you see where the tire is rubbing when you turn left? And just to be clear, the truck has done this since you first purchased it? Did you ask the previous owner what the deal was with the noise and tire rub? Was the lift installed at a shop?

 

My first thought is to pick up a copy of Techstream and the OBD cable and read out the modules to see what errors they are reporting (or find someone nearby who can). It's the same way the dealership or an independent mechanic would start diagnosing the issue. Chances are you'll find some clues in there if it is a module or sensor gone bad and you can get the software and cable for around $40 on ebay.

 

Yep - I was thinking about picking up Techstream. I've got a Bluetooth obd2 reader that I used with my old truck, but it doesn't seem to want to work with the Tundra.

I wasn't able to speak with the previous owner; I bought it from a used dealership.

It's a procomp lift (not sure exact size off the top of my head). I recently took it in to a 4x4 shop to get a few things replaced (coilover mounts, rear shocks, etc.) and they said everything looked fine afterwards (got an alignement and balance done, as well). My impression is that the lift was done by a shop, and is legitimate and in good shape.

It's had these symptoms since I bought it, yes. I got the dealer to knock some off the price for it, so I knew I was getting in to some repair possibilities - just gambled that it would even out at least (the truck was, otherwise, the combo of things I was looking for) - and I needed to get out of my old Silverado before it pooped the bed (and the dealer was already giving me a good price on it, since he didn't really inspect it).

I'll grab some pics later and post (it's been raining all day).

Thanks y'all.

 

Hey y'all.

OK, so I got Techstream this weekend, and ran it tonight.

"VSC Warning Light" is ON (slip indicator is OFF). 4HI is still flashing, but didn't see a readout in that one.

I have NO codes under ABS/VSC/TRAC.

I'm guessing something not the VSC is causing the computer to think that it can't kick in VSC or 4HI bc of some "condition".

I have two "lost communication" codes, which say "no malfunction now" - could be related to firmware/software/etc?

The thing I didn't expect was the series of Evap. Emissions errors. Any clue?

Also, I'll need to check my actual tire pressure tomorrow. Can someone explain the second number in the tire pressure readout (the threshold value)?

I went and did the yaw sensor reset through Techstream, but same result - lights still on. Didn't do battery disconnect after this method, but I'm doubting that will help (didn't when I was doing it via paper clip).

See pics for details. Sorry about the quality - installed this on my wife's old Windows Vista from college (rather than my work MacBook or my desktop) - lol...Vista.

Any thoughts on where I should go next?

"XX Wheel VSC Cntrl Status" is off, yet the VSC warning light is on. Does that mean that VSC is "disabled" rather than on? Wouldn't that light up the VSC Off light?

Could the Evap. somehow be involved in this? Could it be related to the tire pressure and/or sensors.

Check Engine light is not on.

Don't really care about "emissions" (we have no testing here).

Open to any suggestions.

Thanks!

 

Was there a bypass kit put on the AIP?

 

Not that I'm aware of. Is there a visual way I could determine that? The cats looks normal (I've had a previous truck straight-piped).

I'm ordering a new gas cap. Seems these codes can often be related to a leaky seal there.

 

I went ahead and squared my tire pressure at 50 psi all around, and I disconnected the battery over night just to see.

 

Still have the same issue. Gr. Anyone?

 

Pending codes mean that the OBD-II monitoring system has failed the operation of an emission control system at least once and if it fails again the Check Engine Light will be turned on and the malfunction becomes an Active code.
What I would say is reset the code and see if it comes back.

 

Ok, so new gas cap fixed the evap problem.

Back to the main issue...

Using techstream, I ran a bunch of active tests, verifying that various solenoids were going on and off. I did notice that the VSC/TRAC mode is set as "VSC Expert Mode"...

https://www.tochr.net/664/vsc_off_switch_circuit.html (this is for the Toyo CH-R) seems to indicate that this could be related to the brake actuator or something with the parking brake, connectors, etc.

Maybe this is a "brake" issue, that is setting the VSC/TRAC settings/abilities rather than an issue with any of the VSC components (other than brake-specific ones), or yaw sensor/zero-point calibrations, etc.

Also, I can confirm (thanks to some icey roads today) that I have what seems to be zero stability or traction control whatsoever.

And yes, I have tried to check tires/undercarriage (ha) for any loose wires/broken sensors, etc. And haven't seen any. That doesn't mean they aren't there - I'm a new Tundra owner, so I'm just going by my limited knowledge and what I have seen online.

The problem, is that practically no one has this exact combination of lights (steady skid/vsc warning [not vsc off] and flashing 4hi, but no check engine, abs, etc. lights). So I get that something is malfunctioning in the brake/vsc system that is causing the vsc light to go and stay on (shouting "there's a problem with the vsc system" - since it's on even when I'm not moving, telling me that it's not a yaw sensor/actually skidding issue), and that flag in the system is preventing the 4hi from engaging, since under normal operation, you wouldn't be able to engage 4hi during an actual skid. That's my take - but I could be off.

Thoughts?

 

Anyone?

 

While driving do all speed sensors show the same mph in techstream?

 

Have you done a zero point calibration? Sounds like you have a healthy lift on therein order to be running 37’s. If you search zpc on here it sounds like this could be your issue.
Have you checked lower control arm bushings, lower ball joint?

 

I'm going to have someone ride with me today and watch the speed sensors. Will report back.

 

@Adam - yep, I've done the zpc with a jumper and with techstream (in tis I've done the memory erase and the "test" option that also resets...something). I've done this with shims under the yaw sensor and without (currently have three washers under it, as that was the general consensus). Even if I pick up the yaw sensor and physically manipulate it, the skid light doesn't go off. So I'm getting pretty sure it's not related to that anymore.more likely its a speed sensor, wire, etc. under the truck. However, I'm getting ZERO error codes in techstream (or on the dash, besides skid and 4hi).

 

Im having the same problem with my 08 CM. I just got an updated version of techstream. My brake light is on continuously. I do have a bypass kit on. Drives nice, but the lights are driving me crazy

 

So I finally took her to a Toyo dealer and had the mechanic check.

As I told him, he saw no DTCs, but was able to determine that the signal from the 4x4 switch in the cab was going to the transfer case, and then to the front diff, but wasn't returning from the from diff.

From other forums that I've read, this front diff issue seems to more closely resemble my problem.

It seems like it's a 4x4 problem that's blocking the VSC, rather than the other way around.

From reading, it seems like the front diff assembly switch electronics can get corroded. Additionally, the fork in that assembly that locks the front can get stuck.

I tried the "tapping on it with a hammer" fix, but that didn't work. Tried taking that assembly switch cap thing off, but for some reason it's held on with round Phillips head bolts, and not hex, so I can't budge them, yet. Will try some penetrating spray and see if I can get it open to clean the circuits.

He did mention, also, that there is a leak in the breather tube from the front diff, whcih is an issue I've also seen elsewhere that could be related (possibly letting in moisture whcih causes corrosion?).

 

What ever became of this issue?

 

I k ow your frustration. I had been driving with all my lights flashing. I do have a bypass kit in otherwise it would go into slug mode. I tried everything. Zero point calibration, squaring tires at recommended pressure, resetti g co.puter, but vsc,slip indicator and my tps was on. I finally decided to bypass my tps sensor which I saw another post for. I have techstream but didn't solve the issue. But wouldn't you know it, that when I bypassed the pts sensor all light went away for good. Now if my engine light comes on its something to be checked. Hope that helps.