How To Trouble Shoot 4x4 Actuator

Next question. I just pushed the transfer case rod back in and manually took it out of 4x4 h. Is there a way to check if the front is still engaged? I know I can pull the actuator and check where the fork is. It's still up on blocks and transfer case is in 2H now. Front tires spin freely and other side doesn't spin if one is turned. Lights still flashing

 

Nevermind. Stupid me. Yes its disengaged at transfer but if I spin front driveshaft both tires spin. Maybe it is my front actuator after all.

 

Still working this problem. Luckily I can drive the land Cruiser while the Tacoma is up on blocks.
Here is what I figured out today: Both front ADD and Transfer case actuator will work to get it into 4H, but once in the ECU is not getting the message that 4H is fully engaged and will start flashing and nothing will works after that. I can then manually put front back into 2H and leave hanging from wire. Put switch in 2H and insert key. Rear will disengage and lights go out. If i go to put in 4H again, both will work as designed but 4x4 and 4L lights start flashing again. I think my problem is that the signal to send ECU that the front ADD is fully engaged is not working. Tomorrow after work I will see what signals are being sent to ECU.
Looking to follow this:

The transfer shift actuator assembly itself has a few feedback lines (TL1-3), and the transfer case itself has two additional sensors, 4WD and L4. If the inputs don't all reconcile with each other, then it will blink.


In 4WD, they should read as follows;
4WD: 0 resistance to ground.
TL1: floating
TL2: 0 resistance to ground
TL3: floating.

In 2WD, they should read as;
4WD: floating
TL1: 0 resistance to ground
TL2: floating
TL3: floating

The 2-4 transition is like this;
1) TL2 changes from floating to 0 resistance to ground (TL1 and TL2 simultaneously 0 resistance to ground during transition),
2) 4WD transitions from floating to 0R to ground.
3) TL1 changes from 0R to ground to floating. This tells the 4WD ECU to stop the motor.

The 4-2 transition is like this;
1) TL1 changes from floating to 0R to ground
2) 4WD transitions from 0R to ground to floating
3) TL2 changes from 0R to ground to floating. This tells the 4WD ECU to stop the motor.

If at any point, the state of the sensors becomes "impossible", it will error out. For example, TL1 and TL2 can never simultaneously be floating, EXCEPT when in L4 (TL3 0R-GND). There is NEVER a state when TL1 and TL3 can simultaneously be 0V-GND, etc.

It also will use the L4 and 4WD switch states to determine if it is in an impossible state. For instance, L4-GND while TL3 is floating. L4-GND while 4WD is floating.

If it ever finds itself in an impossible state, it will shut down, could get stuck at whatever position it happens to be in.

 

My truck is a 2002 with the 2/4 selector. I'm having a problem getting my transfer case actuator to engage. I was able to find a 2003 Tacoma FSM, however for the transfer case actuator it shows a square 6 pin 2x3 connector but mine is a flat single row 6 pin connector. (see attached photo) I read somewhere, that the 2003 and 2002 FSM should be the same regarding these parts. So im not sure exactly how to test the connections. Also the pictures and walk through's of people opening up their actuator and soldering the connections, neither my a.d.d. actuator or transfer case actuator look like those shown in the pictures. Not sure if the actuators have been replaced at some point prior to me owning the truck. When i push the 4wd switch inside the truck i have no movement or noises. Does anyone have a troubleshooting procedure for me to follow? I've been searching for weeks for an answer to my problem with no luck. Also does this truck have a separate 4WD ECU or is it part of the main ECU. The internet has had a few disagreements on this as well.

 

Sorry. I am not at all familiar with the 1st gen. I thought the 1st gens all had the manual shift on the floor transfer case. Then the front would engage electricity/ vacuum?

 

i could be mistaken with the term 2/4 selector switch vs without, but i have a 4wd lever but as pictured about is has a push button switch as well.

 

so many reports of this problem, but not much follow-up...
would love to see someone that took it to the stealership and can show an invoice of what they did and what the fix was

 

Hello All

I have a 2011 Toyota Tacoma TRD sport 4x4 crew.

My 4 wheel drive light is blinking, won't go into 4Hi or Low

The transfer case shaft is turning ok.

It was working recently. 6 weeks ago and stopped working 4.5 weeks ago.

I washed the engine one day with the pressure washer. reason why i'm adding this info is because I think I got water in the front diff actuator vent while spraying the engine. why else would it stop working, this is the only thing I have done before it stopped working.

I'm thinking of just ordering a new one part# 41400-35033. and just replacing it. if there is water in there then it's good and corroded by now. The dealer wants $880. found one online at Rock Auto for $270 US. should I order from this crowd or are they iffy.

thanks for the help.

 

Rock auto is great for parts, I'll be curious to see what TW has to say about which brand is better:Aisin or Standard motor products.
How do you know it's the front Dif Actuator vs the Transfercase Actuator (rear one)?

Are you Manual Trans? Or Automatic?

I have a similar problem, but not sure really which one is the culprit. Or both.

Good luck, the front Dif Actuator looks difficult to remove ( the top 2 bolts anyway).... take video!

 

You'd be better off going to a junk yard.

 

It's automatic , The transfercase controls the shaft going to the front axels, and it turns when i turn 4 wheel on. but the front wheels won't go in 4 wheel.

 

My 4x4 light comes on randomly and will flash the entire time the truck id running. I can usually turn the truck off, restart it and the light will be off. No idea why it does it so intermittently. 2013 6 speed manual.

 

You’re ADD actuator is starting to go. Take it to the dealership, they’ll tell you they can’t replicate the problem. Wait 3 months, take it back and have them replace it when it’s doing it all the time. Or pull the actuator, clean it out and solder the connectors together. Most of the time that fixes it.

 

i had my add contact points solder and it worked like a charm

 

I took off my front actuator and diiferntial oil spilled out, does anyone know where to refill and how much oil and what weight?

 

There's a fill plug on the differential case - I believe on the driver's side if I remember. You fill it with gear lube spec'd in the manual (I don't remember the weight) until it drips out.

 

how difficult was it to remove? Those top 2 bolts look hard to reach....

 

Top passenger side bolt was a pain in the ass the other three were easy. You cant get it from the bottom, you must enter horizontally. You will need small sized 3/8 or 1/4 drives and 12mm sockets. Also short and medium length 12mm socket. In reality if you have patience it is a easy job. The very frustrating thing is finding the sweet spot to get at the bolt. The actuator is $200 shipped Rock Auto or Parts Geek.

 

cool....thanks for that info. I assume some PB Blaster first, mine look rusty...
I was also curious how you determined it was the front Diff vs the rear ?

 

So I replaced my front actuator light still flashing but have 4wd high but no low. Is there a trick on how to know what position to place the sleeve and what position to place the actuator fork. I assembled the actuator in the default position it was set in.