VSC off and 4wd does not engage

[bayaz]

Hello folks, wanted to bounce off some ideas on troubleshooting the electronics on the 5th gen.

I have 2020 trd off-road models, lifted 3 inches, on 33s. We just recently finished doing a tough trail (involved lots of rock crawling with deep water crossings). About a week after we finished the trail, my 4wd light started blinking. I tried to engage 4wd, but it wouldn’t do it. I turned off the engine a couple of times, and it stopped blinking and 4wd would engage. Then no issues for a few days.

A few days later, a number of lights lit up: multi-Terrain select started blinking (said “Mutli-terrain select not available” despite being in 2wd), it said VSC and PCS were not available, and 4wd icon started blinking again. I turned the engine on and off a few times and it went away. I engaged 4wd low and it worked without issue. No issues for about a day. Then I engaged 4wd low and turned on multi-terrain select, and the whole Christmas tree went off again. This time, it wouldn’t go away, and I haven’t been able to shift into 4wd high or low ever since. Also, occasionally, cruise control would not work.

Based on my search of the forum, it’s one of two issues (or a combo of both): front diff actuator got flooded and seized and/or ABS sensor wires got damaged. I visually inspected the ABS sensors (without a multimeter) and they were not damaged on the trail. The wires don’t look to be chewed up either. The transfer case works (it’s a manual lever), as when I engage 4L, I hear and feel it engage.

Question: how can I trouble shoot if the issue is with the ABS sensors or with the front diff actuator? Should I do a zero point calibration before I trouble shoot? The vehicle is still under warranty, I have doubts that dealer would fix it for free—I want to trouble shoot myself before I take the truck to Toyota.

Please let me know any suggestions you may have.

Thanks.

 

[Jeremy556]

Grab a cable and techstream off ebay to read the codes.

On a 2011 at least, if you have a CEL of any type, it will say MTS Unavailable, VSC, and the ADD will not engage, so 4wd does not work.


Most likely is a stretched ABS wire, I have seen more threads on that than probably anything besides wheel balance issues. If you don't completely remove the ABS wire and disconnect a ball joint, there is a high probability you will stretch a wire. Usually it is damaged in a way that can't be seen, you would need a multimeter.

 

[bayaz]

Well, I took it to the dealer since it’s still under warranty and a local Japanese shop wanted $200 for a complete diagnostic. At the time I took it to the dealer, only the 4wd light was blinking. The dealer appears to have run the more complete code scanner and determined that the issue was with the front differential actuator (ADD) system. They wanted to take it apart and inspect it but called me into the dealership to remove my RCI skid plates. Totally stupid excuse that they “can’t touch anything aftermarket.” The service tech, who appears to know nothing about cars, also kept telling me that if the issue is caused by my aftermarket skid plates, I’d have to pay for the inspection. Curious to see what the dealer finds. I’ve told them that a faulty ADD doesn’t explain stability control and cruise control going off, but, again, the people that actually face customers in the service department don’t seem to know or care about the vehicles they service. So, waiting for them to finish the inspection. If it’s actually the ADD, I suspect that water got in and corroded the connectors, and I can see the dealer refusing to cover it under warranty.

 

[Saker]

….They wanted to take it apart and inspect it but called me into the dealership to remove my RCI skid plates. Totally stupid excuse that they “can’t touch anything aftermarket.” The service tech, who appears to know nothing about cars, also kept telling me that if the issue is caused by my aftermarket skid plates, I’d have to pay for the inspection. Curious to see what the dealer finds………

Can’t touch anything aftermarket!
Strange, my dealership service tech installed my BILSTEIN 5160 & 6112’s on my 2014 and never batted an eye!

The service tech?
Did you mean the service writer, because if the tech doesn’t know anything about cars….. you should have found another dealership!
Service tech is usually referred to as the tech that actually does the service.

Aftermarket skids causing an issue?
Are they bolted to the drivetrain or make any contact with anything other than the frame?
I’d like to know how they can make that statement if that is the case.

I’m on your side, I can’t see any of the connections that service writer stated.

Just sayin’

 

[bayaz]

Can’t touch anything aftermarket!
Strange, my dealership service tech installed my BILSTEIN 5160 & 6112’s on my 2014 and never batted an eye!

The service tech?
Did you mean the service writer, because if the tech doesn’t know anything about cars….. you should have found another dealership!
Service tech is usually referred to as the tech that actually does the service.

Aftermarket skids causing an issue?
Are they bolted to the drivetrain or make any contact with anything other than the frame?
I’d like to know how they can make that statement if that is the case.

I’m on your side, I can’t see any of the connections that service writer stated.

Just sayin’

Thanks, you got it, it’s the service writer. I’ve spoken to two at this point and neither of them seems to understand anything about cars. When I mentioned to the guy that if he told me about the skid plate upon the initial inspection, I would have taken it off earlier and didn’t waste that time. Then he told me that he couldn’t tell that anything about the truck was aftermarket upon the inspection…and we’re talking about a lifted truck that’s over 6’10” overall height with full skids and sliders…yeah..if not for the chance of the warranty covering it, I’d never step foot at the dealer

 

[Saker]

Thanks, you got it, it’s the service writer. I’ve spoken to two at this point and neither of them seems to understand anything about cars. When I mentioned to the guy that if he told me about the skid plate upon the initial inspection, I would have taken it off earlier and didn’t waste that time. Then he told me that he couldn’t tell that anything about the truck was aftermarket upon the inspection…and we’re talking about a lifted truck that’s over 6’10” overall height with full skids and sliders…yeah..if not for the chance of the warranty covering it, I’d never step foot at the dealer

Maybe he’s never actually seen or paid any attention to any 4Runners!

Might be time to seek out a better dealership if there are any in your area.

I’ve heard crazy stories about some that are local to my area and will not go to unless absolutely necessary!

 

[bayaz]

Quick update: approached a different service rep at the dealer. Got the issue diagnosed: failed ADD. Spoke to the tech who told me that the ADD motor failed. I guess it’s a freak issue. Dealer replaced the motor under warranty.