ABS, rear diff lock, TRAC OFF, and VSC OFF lights all on

2017 TRD OR Manual Transmission here with what looks to be a similar problem. All yellow dash indicator lights are solid, rear diff lock blinks. Has yet to go away. Recently had my rear differential worked on. May be related to a sensor back there?

 

We fixed ours by replacing bad fuse

 

Which fuse did you replace

 

The IG2 under the dash. We just got a volt meter and tested the voltages and there was nothing on that fuse. It is a 10amp fuse. This truck was a TRD sport with not e-lockers but we had the ABS, TPS and e-locker were all on. Replaced fuse and boom, all good.

 

Hey guys,

I am having the same issue on my 2015 Tacoma: TRAC OFF, stability control off, rear diff, and ABS. All four lights came on a few weeks ago while driving on the freeway. No accompanying check engine light and no faults whatsoever. Took it to a mechanics shop and they didn't charge me because they couldn't find an issue. Took it to the dealer and the dealer spent all of about 3 hours "looking". When I spoke to the dealer rep he said that their mechanics couldn't find any codes either (surprise), but he said that they did notice two things:

1. They said my steering sensor was off by 360 degrees so the truck thought it was in a turn when it wasn't (they didn't specify which way). I asked if that would throw a legitimate code and he said "typically it does".
2. They also said my tie rods were too short and that I should get longer ones (wtf?).

They refused to work on my truck further unless I take it back to stock..... The only modifications to the vehicle are the front and rear shocks, aftermarket bumpers front and rear, and the upper control arms. The previous owner installed a blue sea switch mod and fuse box, but I don't see how that could relate to the issue with the lights since it is only pulling power from the battery.

From the initial lights being on they have been intermittent. Disconnecting the battery to clear the lights works for a short period of time, but they always come back. They were out yesterday the whole day for multiple starts and stops and about 100 miles until the drive home from work tonight where the rear diff light came on (dim setting) and then shortly after all of them in unison.

I have checked all fuses inside and out, replaced the IG2 under the dash with multiple fuses as well as checked all fuses under the hood. Ive looked at all the cables leading to the wheel sensors as well with no physical defects noted. I read earlier in this post that someone pulled codes by using a shorting wire and did not find any guidance on how to approach that method (is that an option for my year?). I am now at a loss of what to look for or check for next. Truck has 46,000 miles on it and is still under a warranty which probably won't be honored lol. Any help would be GREATLY appreciated.

Thanks!

 

Welcome!

It sound like those guys who looked at your truck are lost. 360° is straight ahead, same as 0°. They're fishing. Take it to another shop.

 

Thanks for the reply! I think they just needed to say something in order to justify the cost associated with their ineffective inspection. I am trying to avoid taking it to another shop at the moment due to money constraints, and I would hate to shell out more cash for a problem that a qualified mechanics shop and dealer couldn't find.

 

Understood. Try verifying all pertinent sensors are recieving correct voltage and outputting correct voltage. Once you get wires and buses out of the way, only components are left. Good luck diagnosing your problem!

Hopefully someone will come with a link to the wiring diagram.

 

Update:

Rear diff light (dim) comes on first every time now, and the rest follow shortly after.

I can get them all to reset by putting it in 4lo and attempting to engage the rear locker (I say attempting because the bright rear locker light is blinking while the dim rear locker light is on), and then upon "unlocking" the rear diff, all the lights go out.

Last night I was messing around with it in the dirt and the rear locker didnt feel as if it had engaged however the light progressively got brighter while blinking until it appeared solid. I've never had the need to lock the rear, but that seems weird. Should be either bright solid or flashing right? I didn't notice a clunk or audible sound that the rear was locking and unlocking. I was using the methods prescribed with locking the rear such as 4lo, slow turn, etc....

Next steps?

 

I would be investigating the wiring to the rear end locker. From the dim light indicator that comes and goes on its own I would suspect a ground on the wiring somewhere.

 

Yes look at the rear diff lock connector and the actual sensor as when the diff is locked it sends a signal back to turn OFF the ABS, TRAC, and VSC so you can dig yourself out without the engine management ramping down the throttle and tapping the brakes to reduce wheel spin. That is the Off-Road model advantage. Do dash lights go off when you disconnect the diff lock connector on the diff?

 

Saw these replies at work today. Decided to start disconnecting cables in the parking lot since the lights came back on during my lunch break. First connector I disconnected did the trick.... all the lights went out. Reconnected and they were all back on. Repeated these steps a few times to be sure. Got home and looked up the component and it's center diff lock switch. I took it off and cleaned it as best I could with a rag and some DeoxIT spray and then reinstalled. Lights are out now. Really hoping this did the trick! Will report back after I've put some more miles on it.

Thanks for the responses!

 

I'm always full of suggestions, or something...

 

Just a heads up I had the same problem with all my lights on. I took it back to the dealer and they stated that the cam sensor may have caused this. The cleared the code, changed the oil and stated that if the lights came back on the motor would have to come out. Now just waiting for them to get a tacoma in so they can fix the truck. I posted the info on another post a couple months back. Just a shot to give you another avenue to check to get your problem fixed. Good Luck

 

What code was there to clear? I'm not getting any codes at all, just the 4 lights.

 

The code that was stored was P0012 cam over retarded timing bank 1. When the lights were on it did not have any code other than a stored code. They changed the oil and said if the lights come on again they have to pull the motor apart to check the timing chains. The lights came back on for a while but no code and then they went out.

 

For sure. When I took it to the dealer they told me there were no stored codes and to go kick rocks lol. They said they can't work on my vehicle unless I take it back to a stock configuration. Let's hope I dont have the issue you're experiencing.

 

How many miles on your truck. I would find another dealer that has a clue what to look for. The tech that looked at my truck knew what to look for as soon as I told him what was going on.

 

47,000 miles. I am gonna put some more miles on it now that the lights are out after messing with the switch. Not too happy with the first dealership interaction.

 

*SOLVED* (for me at least)

Light had come back on 200 miles after cleaning the switch so I purchased and installed a new one from toyota right before my road trip to Colorado and Utah where I put 2,000 miles on it. No lights the entire trip so I will go ahead and say its confirmed that the reason the lights were coming on was due to a faulty differential center lock switch. Thanks for all the help with this issue guys. I have atteached a picture of the switch disconnected in case someone else has this issue in the future.