4wd system won't engage???

I have an '07 TRD that won't engage into 4wd high when I rotate the knob. The dashboard icon continues to blink and it will beep if I try to put it in 4wd low. I took it to Toyota of Tampa Bay and three hours later was told that the service technician couldn't figure it out and would need to consult their tech service line - that's been two weeks and I have no faith in these yahoo's. Has anyone else encountered this issue and what was the fix? Thanks.

 

I dont know if it helps any but my truck only likes to go into 4hi while idling in drive. To get into lo i let the 4hi engage first then stop and put truck in neutral then turn to 4lo and it will engage. If im stopped and try to put the truck in 4hi though it doesnt want to engage.

 

Thanks for the suggestion. I should have also said that it's a 6 speed manual.

 

Mine will do the same thing but only for a few mins.. I'm leaning towards the front diff having original oil at 87,000 miles or the ADD is acting up.
(5speed auto)

 

Clutch switch bad/malladjusted? It has to be all the way to the floor some times even a after market mat will be enough to not let it engage.

 

If the service tech couldn't get it to engage, I'm guessing something really is wrong. Before the Tcase will engage it needs a signal from the ADD to the 4wd ECU, so it could be anything in that loop.

 

There is an actuator that can go bad. Mine recently had the same issue. Here is what the dealer history said:

*TRANSMISSIONS ~|~CUSTOMER STATES WHILE DISENGUAGING FOUR WHEEL DRIVE THE LIGHT BLINKS, XFER CASE DISENGAUGES HOWEVER ELECTRICALLY DOESN'T DISENGAUGE ~|~FOUND DIFF LOCK ACTUATOR LOCKED UP ~|~REMOVED AND REPLACED ACTUATOR TO CORRECT Parts Name Part # QTY ACTUATOR ASSY, DIFFE 4140035031 1

 

My 06 did what you described @ 16k.
Nothing would make it engage.
I finally lost 4Lo too.
The truck was under warranty & the tech used the service line & replaced the front diff actuator.
There are other threads on this if you read to help diagnosis.
The part was like $350 but Toyota paid for it.
Do you have a warranty or out of pocket?

 

I'm past warranty and this is really frustrating first because the dumbass tech said he didn't know what it was and second, they still haven't got back to me regarding what their so called service tech line (specialist?) thinks. The actuator makes sense as I am having no other electrical issues. Although it's an '07, I only have 24,000 miles on the truck and the 4wd system has never been abused. Sure does make me miss the days of manual hubs and a 4wd shifter. Thanks guys for your comments.

 

FYI for those telling you different .. you can switch it into 4hi while moving (up to 60mph in fact) and in gear (clutch doesn't have to be in). Not for 4hi. Ask the tech if he tried a different actuator. Maybe that's not it.

 

Try turning the switch, turning the truck off, then back on. I generally have troubles getting mine to switch out. If all else fails it will work every time if I turn the truck off, it will immediately click back over when the key is on.

Generally though, if I have troubles, I'll usually tap the gas a little bit, which jives the drivetrain enough and releases enough stress that it will click out.

 

I've had problems in the past. I searched for a service manual and I think there is a thread on here somewhere that posts one. I used it to diagnose myself. The dealer also couldn't figure it out. The 4x4 ecu is located under the dash behind the glovebox beside the ac vent up high. U can start there to make sure its receiving and sending signals correctly

 

Since new mine has never gone to 4 lo. It sits there and flashes at me and beeps until I turn it back to 4 hi. I don't think there is anything wrong, I just might be doing something wrong.

 

i have a buddy that bought an 05 brand new and the first time we went off road his 4wheel drive wouldnt work and it wound up being the actuator. of course it was still under the factory warrenty.

 

Do you put it in N then switch to 4LO ?

 

Sure did. I even tried it in every single gear and it didn't do anything. I haven't tried turning the truck off while the switch in engaged to 4 lo though.

 

I'm kind of bummed I never did anything about it. Mine is a little over a year old and I'm about to hit 50,000 miles.

 

It goes into high just fine. When I try and select low it just beeps and flashes.

 

Thanks! I'll report back with my findings tomorrow.

 

Have you figured it out? I'm having the same issue with my manual and it is making mad.... lately the truck hasn't even been shifting out of 4hi to 2 and the diff hasn't been locking as well..... I bought a Tacoma to avoid these issue...