beeping coming from front Diff?

So I have a 4x4 and my 4 wheel drive has been acting up lately. starting the truck in 2 high, the 4X indicator light flashes and continues to flash, but 4x doesn't engage. try to put it into 4 wheel and it won't engage. Now I can hear a faint beeping coming from somewhere near the front diff. The stealership told me the ecu was having trouble recognizing the tire size due to irregular tire pressure, thus confusing the ecu. they old me to run my 33's at 42 pounds. tried that and they're full of shit, it didn't work. Anyone have any ideas on what's going on?

 

As far as I know (from all i have read) there is no beeper / speaker anywhere on the front diff. There should be a loud beeping coming from the dash when 4 LO fails to engage.

 

why can't they just go back to the manual locking hubs. no worries with em'.

 

x2.hmmmmmmm

 

They are more durable, but then you have 99.9% of the Tacoma owners bitchin' that they have to get out and twist the hubs. There is enough whining now about lack of heated seats, heated mirrors, courtesy light, no illumination on 4x4 switch, etc that I doubt they'll want to get out and twist some hubs once their stuck it snow/mud.

Good idea and I agree, but I think 99.9% of Tacoma owners will give Toyota grief over it for sure.

 

the beeping is coming from underneath somewhere near the front diff. no idea exactly what's beeping. I'd rather have the manual shifter. seems like the more electrical stuff trucks have, the more can go wrong. They need to keep things more mechanical

 

Is it like an electronic beeping from an actual beeper or a whistle or whining noise from something electric or mechanical?

There should be vacuum lines that run to the front diff for engagement. Maybe one of them is leaking?

 

it's like an electronic beeping

 

Video/Audio from IN CAB and UNDER the truck please!!

 

What was the issue. I am having same problem. Aftermarket dorman actuator just installed. Now it’s beeping and 4wd hi light flashing

 

your issue is the dorman unit, it’s junk right out of the box.

 

The 4wd engages and dis engages fine but the 4x4 light flashing green. It was flashing green and 4wd wasnt working and my actuator was full of water so I installed this one. Tried leaving battery unplugged a bit to see if it would reset. But no luck.

 

unplugging the battery will do nothing for the 4wd ECU, it doesn’t have any kind of “memory” or store codes.

 

Check your limit switch voltages as outlined in the thread below, I'll bet you find one of them isn't working properly or you have the Transfer Case Actuator mis-timed.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

Thanks! I’ll check it out tomorrow. I was just looking to see if I could rest the 4wd ecu. The original problem was the green light was flashing so I removed the stock actuator and opened it up and greased the gears and soldered the connections. I had a small amount of water in it. Found hole in top vent line. Replaced hose. Reinstalled and everything worked great for about a month. Then 4x4 light started flashing. Would not engage in 4wd. However if I switched to 4hi when truck was off and then turned the key on, it would go into 4hi. Then 4lo and back to 2wd. Then about a week later it stopped working all together. I order a new dorman actuator and installed today. Opened up the old one and full of water. Found crack in lower hose.
installed actuator and drained and refilled diff. Tested and green light flashing but 4hi and 4lo work and lights stay solid like they are supposed to. Then back to 2wd and goes into 2wd but light flashing. And the new actuator is beeping. I’m lost lol.

 

Woke up this morning and started the truck to drive it down to the garage and the 4wd light not flashing now. Everything works as normal. I’m lost lol. I have no idea. Will see if it stays this way. Only time will tell.

 

Update: All is working as normal. Still no issues. Hasn’t beeped again and have used the 4WD many many times. Guess it was programming itself. I contacted Dorman when it was happening and the guy didn’t have a clue about it.