Flashing check engine and traction and 4LO lights "fix?"

[4mydogs]

About three months ago those lights came on on our 2012 Sequoia. It was on a weekend and I did the best/worst thing I could do and searched the internets. Saw a youtube video in which a guy claimed that if you disconnected both battery cables from the battery and then touched both with a wrench it would "fix" it. It did make all the lights return to normal. Last night it happened again. The quick "fix" worked again. What is actually happening and are we driving around in a time bomb that's going to go off where this procedure won't work again?

 

[SoCal818]

About three months ago those lights came on on our 2012 Sequoia. It was on a weekend and I did the best/worst thing I could do and searched the internets. Saw a youtube video in which a guy claimed that if you disconnected both battery cables from the battery and then touched both with a wrench it would "fix" it. It did make all the lights return to normal. Last night it happened again. The quick "fix" worked again. What is actually happening and are we driving around in a time bomb that's going to go off where this procedure won't work again?

Have you tried pulling the codes?

 

[Jetboy]

My 2016 Tundra did a similar thing once. It happened when pulling up my low slope driveway in a very icy condition. We had freezing rain ice sheet with light wet rain on top. Just incredibly slick. I went to pull up in 2wd. Traction control I think freaked out thinking something must be broken because one abs signal was speeding up while the rest were at zero at idle with no throttle input. That's my best guess. I thought it was some major issue. I pulled the rear ABS sensors off and looked for issues in the sensor areas. Thought maybe i had a broken ABS line (I've had that 2x in my 4Runner from offroad abuse). Nothing wrong. Battery reset and it's never returned.

If it's happening more often - it could be an abs sensor or abs sensor wire issue.

 

[4mydogs]

Have you tried pulling the codes?

Going to try to do that this weekend.

 

[LandCruisinMy93]

@4mydogs Did this just come on randomly, or was there a preceding event/events? Traction control, and check engine can come on for numerous reasons, usually if the check engine and traction control are on like that it's a wheel speed issue or related sensors, potentially throttle position sensor issues as well. My 03 did did it every time the weather dipped into the high 20F range. I carried scan tool in the pocket on the back of the driver seat just to reset the lights. If the 4-lo is blinking, I'd hazard a guess that you are dealing with transfer case or differential actuator issues. Do you have an all-wheel drive or selectable 4 wheel? How often do you exercise your actuators? Do you live in the rust belt, an area that salts roads or near the ocean? If it has the selector switch, go drive under 55mph and switch it into 4Hi, drive around a bit, maybe 10 miles at a time, switch it in and out of 4Hi. Then, go find a crappy gravel or dirt road, put it in Neutral, switch it to 4LO and wait for it to actuate. Put it in drive and drive around a bit, stop, neutral, switch to 4Hi, go and repeat the stop, neutral, 4Lo until actuation is quick. To me, it sounds like your Sequoia thinks you either tried to go into 4LO or your actuator is stuck in between being engaged and not. It may help to disconnect the transfer case actuator plug and clean the pins and terminals really well, put some dielectric grease on them and plug it back in...same with the front axle disconnect actuator.

 

[4mydogs]

@4mydogs Did this just come on randomly, or was there a preceding event/events? Traction control, and check engine can come on for numerous reasons, usually if the check engine and traction control are on like that it's a wheel speed issue or related sensors, potentially throttle position sensor issues as well. My 03 did did it every time the weather dipped into the high 20F range. I carried scan tool in the pocket on the back of the driver seat just to reset the lights. If the 4-lo is blinking, I'd hazard a guess that you are dealing with transfer case or differential actuator issues. Do you have an all-wheel drive or selectable 4 wheel? How often do you exercise your actuators? Do you live in the rust belt, an area that salts roads or near the ocean? If it has the selector switch, go drive under 55mph and switch it into 4Hi, drive around a bit, maybe 10 miles at a time, switch it in and out of 4Hi. Then, go find a crappy gravel or dirt road, put it in Neutral, switch it to 4LO and wait for it to actuate. Put it in drive and drive around a bit, stop, neutral, switch to 4Hi, go and repeat the stop, neutral, 4Lo until actuation is quick. To me, it sounds like your Sequoia thinks you either tried to go into 4LO or your actuator is stuck in between being engaged and not. It may help to disconnect the transfer case actuator plug and clean the pins and terminals really well, put some dielectric grease on them and plug it back in...same with the front axle disconnect actuator.

Thanks, I didn't get to do anything with it over the weekend and I'm getting ready to go out of town with it. We'll see how she goes.

 

[06Speed6]

This happened to me on a cross-country trip in my 2012 Sequoia. I pulled the codes, and it was a transmission turbine speed sensor, which is engineer speak for a senor that measures the rpm of the torque converter. The transmission went into some kind of limp mode and wouldn't shift into overdrive. Otherwise, everything drove normally.

I remember it being a $50 part at Autozone. It took about 30 minutes to swap it out, with nearly all of that time spent trying to find it on the transmission. It was on the upper part of the front of the transmission on the passenger side. You can't really see it. You have to work by feel.