A Little Different Four Wheel Drive Problem

Already did a search. 2015 TRD Off Road 4X4. After driving four miles in 4Hi on a snow covered muddy road outside temperature about 40 degrees, I turned the transfer case knob to back 2Hi when I hit dry pavement. The transfer case remained in 4Hi. The four wheel drive light on the dash remained lit regardless of the position of the knob…no blinking I did the usual stuff to disengage four wheel drive…taking foot off gas, stopping and shifting to reverse, etc. No luck. Drove home and parked truck in my heated garage. Came back four hours later and turned the knob to 2Hi. It immediately disengaged 4Hi even before the truck was moved and the four wheel drive light went out. Right now the truck is in 2Hi. I am very leery of shifting to 4Hi to see if everything is OK. I live thirty miles from the dealer and I really don’t want to drive that far on dry pavement if the truck will not shift from 4Hi back to 2 Hi. The transfer case and front and rear differentials were serviced at about 95,00 miles. The truck has 102,000 miles on it. I frequently use four wheel drive. Has anyone else dealt with a similar situation? How was it resolved? Could this have been a temporary glitch in the transfer case ECU that was corrected when I turned the truck off and then restarted it several hours later? Could the warm garage been a factor?

 

The same thing happened to me once this winter, after turning the truck off and re starting the 4wd shifted normal. I have no idea what caused this and it only happened once

 

Have you since tried engaging it and disengaging it while driving?

 

Nope....waiting to try until I am close to dealer's shop. Sometimes prudence is good.

 

Thanks for the response. Hope this happens for me. Think that s till want to have a Toyta tech check it out

 

I don’t have a solution for you but you don’t have to worry about driving 30 miles or so on dry roads in 4H. It won’t harm the 4wd system. What stresses the 4wd on dry surface is making turns. Going straight is no problem. If you have to drive in 4H to the dealer, what ever turns you have to make, make them as wide as possible. Distress to the 4wd will be minimal. No need for concern.

 

The electronic 4wd system on these trucks is a bit suspect after it ages. There are actuators on the transfer case and front diff that are both known to have moisture intrusion and have the contacts corrode preventing operation. The wires may be damaged preventing power/signal from properly transmitting. The ECU may have degraded.

Because it's intermittent and there are so many possible causes you will need to spend some time testing and may not identify the actual cause.

There are some good threads here on how to troubleshoot the various components.

 

Thanks for the comments. My wife and I have been driving four wheel drive trucks and "real" SUV's exclusively for almost 40 years...15 vehicles (six 4X4 Tacomas). Have had only two problems...front hubs on a Chevy and an actuator on a Ram. Although I am an avid truck guy, I am no mechanic. Best leave the trouble shooting to a good tech. I really want to be able to explain what is possibly going on to the tech. Thanks again.

 

Being able to describe the conditions when it didn't work are important. Was it wet/dry, hot/cold, had you been driving long time/short time? Have you noticed this problem previously? Have you tried it again under different conditions? A Toyota tech should be familiar with the issue as it's not uncommon, but you don't want them throwing parts at it as they are all expensive, but you also don't want to pay shop rates for hours of troubleshooting.

 

Here ya go.
I bet this is it:

https://www.youtube.com/watch?v=ZJESG91GbCQ