How can I get my wheels to spin with the truck lifted off the ground?

[fdbyrne]

I've got a vibration that I'm trying to track down. To isolate the problem I lifted all four wheels off the ground, started it up and put it in gear. With the vehicle in drive and the engine idling the rear wheels spin fine. As soon as I give it any gas, all the power is cut and I'm not able to accelerate. The same thing in 4HI. I can lock the differential and get all four wheels going but only at idle.

I'm pretty sure it has something to do with the traction control. How can I get full throttle response on a temporary basis just for diagnosis purposes? I have no intention of making any permanent modifications.

I did this with my 1st gen Tacoma with no problems and it was really helpful in finding the problem. All the electronic wizardry is getting in my way with my 4Runner.

 

[foxtrot]

Although this sounds dangerous, hopefully you are taking the correct precautions. To disable the traction control, unplug the plug that is connected to the brake fluid resivoir. This disabled the system.

 

[fdbyrne]

It is dangerous and should definitely be done in a controlled manner taking all possible precautions. It's a great way to rule out tire noise, bearings, and a few other things real quick though. It's also a really good way to convince your neighbors that your either crazy or a redneck or both.

I read about pulling that plug but there seemed to be a little confusion as to whether or not it would work on a 2003 to 2005 model without having to do a zero point calibration afterwards. Can anyone confirm that pulling the plug, running a quick test, and plugging it back in won't result in any odd side effects?

 

[NinjaOne]

It is dangerous and should definitely be done in a controlled manner taking all possible precautions. It's a great way to rule out tire noise, bearings, and a few other things real quick though. It's also a really good way to convince your neighbors that your either crazy or a redneck or both.

I read about pulling that plug but there seemed to be a little confusion as to whether or not it would work on a 2003 to 2005 model without having to do a zero point calibration afterwards. Can anyone confirm that pulling the plug, running a quick test, and plugging it back in won't result in any odd side effects?

Doesn't dropping it 4Lo disable it as VSC as well? Or loosening the gas cap?

I woudln't be worried about doing a zero point cal, super easy with a coupe of paper clips

You got it on a lift or doing it on jack stands?

 

[Onefastchevy]

There are several threads on here regarding shutting off the traction control, I haven't seen one that mentions a calibration needed after, only to shut off the truck and then turn it back on.

I would suspect 4lo wouldn't give the speed needed to find the vibration.

 

[fdbyrne]

Thank you guys. I appreciate the advice.

I'd prefer to do it on a lift for obvious reasons but I don't have that luxury. I have enough giidy, sturdy jack stands and a perfectly level garage. It can be done safely enough to be worth the risk.

 

[Jixxer6]

I will typically just disconnect an abs wheel speed sensor.

Edit:
If you unplug a sensor the trac won't be able to work because it won't be receiving any wheel speed data. I do it regularly at work

 

[t-man]

Just lock the differential. The traction control see's one tire moving faster and is engaging. Locking it in should help. Disconnecting the plug by the master cylinder as stated above will work too.

 

[fdbyrne]

Locking the differential didn't help much, actually. I was surprised.

 

[t-man]

Locking the differential didn't help much, actually. I was surprised.

It's because there isn't a locker. Will have to disconnect the wire.

 

[BlackWorksInc]

Unplug the pressure sensor on the master cylinder, it will kill the system. ZPC should not be erased, did this last Sunday in the snow for a couple recovery attempts, haven't had to reset ZPC yet.