Thanks a ton! I think the tech actually performed these tests - based on him being able to say whether the ADD motor works or does not. But I was never given a detailed result—they probably found it more economical to just replace the ADD.
Toyota 4wd Reliability?
- Thread starter bayaz
- Start date
Thanks a ton! I think the tech actually performed these tests - based on him being able to say whether the ADD motor works or does not. But I was never given a detailed result—they probably found it more economical to just replace the ADD.
Jakeepoo3
New member
We know the motor works is what I'm trying to tell you. Intermittently. Motors don't work just intermittently. Failures in the circuit cause intermittent motor operation. He said there was communication signal problem between modules. Which could mean anything that could go wrong. Covering his ass.. the diagnosistic above he didn't do. These diagnostics check the internal limit switches, ADD detection switch inside the module are functioning/engaging properly. But f_ck if your warranty covers it get a new one again and again. Keep the old one this time!
Yeah, I hear ya. I don’t wanna replace the functioning ADD-I just don’t want it to fail on the Rubicon or in the middle of Nevada desert. I’m taking the truck to the dealer on Monday, and I just hope there’s service rep that was decent. The first time I took it to the dealer, another service rep told me the 4wd failure won’t be covered under warranty because I had aftermarket skid plates..made me learn quickly that guys who work at the dealership know nothing about cars.
Jakeepoo3
New member
Hilarious. Aftermarket skid completely ****ed your 4wd, that's a new one.. request all your service records on this issue if you don't have them already. Talk to the shop manager only from now on. They may not know much as you said but also they are also assuming you don't know jack sh1t.. doing the same thing over and over again expecting different results is the definition of insanity.. make sure you have all documentation from when you first had this issue. If you do have an accident or wanna get real slick and pull a scam on these c0ck suckers you should be covered with all documentation. This is a safety hazard as far as I'm concerned and shouldn't even be on the road.
I appreciate you being being mad about this too. I think to me this is the issue that’ll make a break whether I get a toyota 4x4 again.
PS, based on research, many people have the 2WD to 4WD malfunction when the prongs within the ADD motor lose connection. People just solder them to be safe. But it doesn’t make sense in my case because all I need to do is to restart the engine and the code clears.
BlackWorksInc
New member
You keep saying that the terminal ends break... I honestly can't recall seeing that? You have pictures, I'd be curious to see what you mean.
As for the issue, I am leaning on either an issue in the actual electrical circuit causing a hiccup or some sort of odd mechanical issue inside of the differential jamming up the mechanism occasionally. I'd start with the electrical side of things since that's the easiest to test and go from there. It doesn't seem like an ECU issue to me, it's still a possibility; but it seems odd to me that it would occur intermittently and then outright fail (like your two prior situations).
As for the issue, I am leaning on either an issue in the actual electrical circuit causing a hiccup or some sort of odd mechanical issue inside of the differential jamming up the mechanism occasionally. I'd start with the electrical side of things since that's the easiest to test and go from there. It doesn't seem like an ECU issue to me, it's still a possibility; but it seems odd to me that it would occur intermittently and then outright fail (like your two prior situations).
I don’t think terminal ends is currently the issue because the current issue fixes itself by restarting the vehicle. I do think that the terminal ends could have been the cause of the blinking 4x4 sign that was “fixed” with a mallet. Strikes could have made the ends touch.
There are many videos talking about this issue:
Toyota Tacoma | No 4wd Fix | 2wd / 4wd Mode Malfunction Fix | (2017 Tacoma) - YouTube
Toyota Tacoma front axle 4x4 actuator (ADD) fix - YouTube
Toyota Tacoma's 4x4 Issues | 2wd to 4wd change failure How To Fix - YouTube
BlackWorksInc
New member
Ah I see what they mean, it's been a bit since I took one apart (last 3-4 I did in the past few years have been warranty so had to send the parts back). They basically do them like large power mirror motors, "drop-in" style; I suppose I could see them developing poor contact over some time due mainly to moisture intrusion and carboning. Though the weird thing in those videos and other pictures of the ADD being torn apart is there's no real fixture/support for the contacts... in power mirrors there's a sort of plastic cradle/support for the contacts so they stay fairly well seated; the contacts are also springy so they press against the motor ends to maintain contact.
In any case, it's likely not the issue we're dealing with. I'm still leaning on something funky going on electrically in terms of signaling/commanding the system and/or something mechanically interfering with the operation of the ADD and prematurely burning it out.
Jakeepoo3
New member
Speak.
If the dealer doesn’t solve it, I’m happy to show the truck to y’all if you’re on the west coast. I’m doing gears next week and putting a locker in the front, so I’m pretty certain they won’t fix anything under warranty after that
Jakeepoo3
New member
Dirty south Arkansas representing! If they can't solve it how did it get engineered and built. F_ck tarded. Reverse engineering alien spacecrafts no problem. It's their broken truck not your fault. How can they possibly get away with that. Need to get an electrical engineer in there not a technician if he doesn't have the ability to do the job. Have you read your warranty front to back for loopholes or other options? Sounds like an attorney might be helpful but $$$$ expensive. I don't know what to do if they can't resolve it besides do it myself. What a joke.
BlackWorksInc
New member
If I still lived in the Bay Area I'd actually tell you to either schedule with my old dealership and ask for me or just stop by on a weekend and we'll take a quick look. Unfortunately I moved out north to Central Oregon.
Since It’s just electric stuff, maybe I can just grab a multimeter and test it myself if it comes to it. I’ll need to study more on the diagrams you shared.
Well, now the 2WD to 4WD Mode Malfunction warning doesn’t go away (along with blinking 4L and multi terrain select malfunction). Maybe that’ll help when taking it to the dealer tomorrow. Notably, also, the malfunction warning came up again AFTER I put the truck in 4L (constantly testing it now), and it showed 4WD as disengaged even after it engaged when I put it in 4L. Sketchy moment..
Jakeepoo3
New member
Yes sir you can! You'll need long leads or extensions to reach between the add and the 4wd ECU. Maybe alligator clips. Some good kits out there have all the multimeter accessories that make it way easier doing it alone. A test light is my favorite electrical tool. You can diagnose anything electrical with these two simple tools.
Well, boys, the dealer took a look at it again today. Said the same thing failed as the second time, which is not the motor (this failed the first time, but not the second time). The rep said their mechanic wanted to ask me if I did any extreme off-roading or do anything unusual with the vehicle. Said they’ll be replacing the ADD again as didn’t find any other issues. For reference, see first two dealer reports below:
1)
TECH(S): 158
CUSTOMER STATES THAT 4WD WARNING SIGN IS ON/OFF AND CUSTOMER STATES NOT ABLE TO ENGAGE 4WD.. PLEASE CHECK CONFIRMED 4WD WARNING LIGHT IS FLASHING. CONFIRMED ON LIFT VEHICLE IS NOT GOING INTO 4WD, FRONT DRIVE SHAFT IS SPINNING
BUT FRONT WHEELS ARE NOT. THERE IS A CODE STORED IN ABS ECU C1258 OPEN CIRCUIT IN TRANSFER 4WD POSITION SWITCH. CUSTOMER HAS INSTALLED A AFTERMARKET PLATE UNDERNEATH VEHICLE WHICH NEEDS TO BE REMOVED IN ORDER TO AXCESS FRONT ADD ACTUATOR FOR INSPECTION.
(After I removed the front skid, they replaced the actuator)
2) DIAGNOSIS
TECH(S): 158
CUSTOMER STATES 4 WHEEL DRIVE WONT ENGAGE BROUGHT IN JULY FO FOR SAME ISSUE PLEASE CHECK AND ADVISE CONFIRMED 4WD LIGHT IS FLASHING WITH THE VEHICLE IN 2 HI, AND THAT THE VEHICLE WONT GO INTO 4 HI. WITH TRANSFER CASE
IN 4 HI THE FRONT DRIVE SHAFT IS SPINNING, BUT THE FRONT WHEELS ARE NOT SPINNING. CONFIRMED THE TRANSFER CASE 4WD POSITION SWITCH HAS CONTINUTY WHEN IN 4WD, AND NO CONTINUTY
WHEN IN 2 HI. MANUAL POWER UP FRONT ADD ACTUATOR, AND WAS ABLE TO PUT THE FRONT DIFFERENTIAL IN 4WD. CREATED TAS CASE,
CASE NUMBER 220460284. RECOMMEND REPLACING THE FRONT ADD ACTUATOR. AND RECHECK FOR PROPER OPERATION.
REPLACED THE FRONT DIFFERENTIAL ADD ACTUATOR, AND RECHECKED.
THE 4WD LIGHT IS NO LONGER FLASHING, AND THE VEHICLE WILL GO IN, AND OUT OF 4WD.
1)
TECH(S): 158
CUSTOMER STATES THAT 4WD WARNING SIGN IS ON/OFF AND CUSTOMER STATES NOT ABLE TO ENGAGE 4WD.. PLEASE CHECK CONFIRMED 4WD WARNING LIGHT IS FLASHING. CONFIRMED ON LIFT VEHICLE IS NOT GOING INTO 4WD, FRONT DRIVE SHAFT IS SPINNING
BUT FRONT WHEELS ARE NOT. THERE IS A CODE STORED IN ABS ECU C1258 OPEN CIRCUIT IN TRANSFER 4WD POSITION SWITCH. CUSTOMER HAS INSTALLED A AFTERMARKET PLATE UNDERNEATH VEHICLE WHICH NEEDS TO BE REMOVED IN ORDER TO AXCESS FRONT ADD ACTUATOR FOR INSPECTION.
(After I removed the front skid, they replaced the actuator)
2) DIAGNOSIS
TECH(S): 158
CUSTOMER STATES 4 WHEEL DRIVE WONT ENGAGE BROUGHT IN JULY FO FOR SAME ISSUE PLEASE CHECK AND ADVISE CONFIRMED 4WD LIGHT IS FLASHING WITH THE VEHICLE IN 2 HI, AND THAT THE VEHICLE WONT GO INTO 4 HI. WITH TRANSFER CASE
IN 4 HI THE FRONT DRIVE SHAFT IS SPINNING, BUT THE FRONT WHEELS ARE NOT SPINNING. CONFIRMED THE TRANSFER CASE 4WD POSITION SWITCH HAS CONTINUTY WHEN IN 4WD, AND NO CONTINUTY
WHEN IN 2 HI. MANUAL POWER UP FRONT ADD ACTUATOR, AND WAS ABLE TO PUT THE FRONT DIFFERENTIAL IN 4WD. CREATED TAS CASE,
CASE NUMBER 220460284. RECOMMEND REPLACING THE FRONT ADD ACTUATOR. AND RECHECK FOR PROPER OPERATION.
REPLACED THE FRONT DIFFERENTIAL ADD ACTUATOR, AND RECHECKED.
THE 4WD LIGHT IS NO LONGER FLASHING, AND THE VEHICLE WILL GO IN, AND OUT OF 4WD.
Considering they’ll be replacing the same part the third time, I’m concerned it’ll go again. Except, I’m re-gearing and putting a front locker, so I’ll be probably SOL on warranty next time it fails. I can’t imagine any kind of off-roading will put additional strain on the actuator, but I’m trying to understand what I can do to prevent it. Dealer said they never had ADD fail 3 times on one truck
Jakeepoo3
New member
He really asked you if you off road! Don't answer that irrelevant, sidetracking sh1t. So when it does go into 4wd according to the dash the front drive shaft spins but not the front axles.. not even three wheel drive? It's like the add isn't even there period. At least he discovered this we haven't been told of this symptom. You have full coverage insurance? Fly that c_nt off a cliff. It's not her fault, Toyota is responsible and ruining an innocent trucks quality of life. Poor girl
Yeah, the first tech was the one who told me that aftermarket skid plates could affect the diff. Maybe I can just put manual locking hubs
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