Check engine and Trac Off lights on at same time

So glad we have this forum. Yesterday I filled up my tank, all normal and came back home. This morning took my daughter to school and nothing neither. One hour ago, I started my car and both lights went on. Check Engine and Trac Off. It's a Scion XD 2014, 40,000 miles only. I checked the gas cap, asked my mechanic to order a new one just in case. I'll check with him what's going on with the trac off light tomorrow.

Forgot to mention, yesterday I passed a big hole on the road, couldn't avoid it. Maybe has something to do with it ?

Any idea ?

Hit a big bump? Maybe just a sensor got knocked lose. Poke your head under the hood and start wiggling things.

You could also get yourself an OBD2 scanner. They're pretty cheap now.

Dirty wheel speed sensor I bet.

Blast brake cleaner in it, you can see where its at by looking for a wire that runs to sensor, its near, wheel hubs.

Start and run a couple times to see if it clears, or sm1 will need to clear the fault code with a obd2 reader.

Added...super common in cars in snow, ice and salt.

a reply to: AnonymousCitizen

Haha jinx

originally posted by: AnonymousCitizen
Hit a big bump? Maybe just a sensor got knocked lose. Poke your head under the hood and start wiggling things.
You could also get yourself an ODB2 scanner. They're pretty cheap now.

I'd like to know where exactly the sensors are. Right now is raining but early morning I could take a look.

I'll second the scanner idea. Good thing to have around, and decent ones can be had pretty reasonably.
You can even get ones that are a little module that plugs into the diagnostic port under the dash and Bluetooth to your phone with an app you Download.

Coming up with and idea though on what it could be with the info you have right now though would be shot in the dark guess work at best.

You can though also get the codes read at most auto parts stores for free.
Once you have the codes, you can ask here, or Google them to get a pretty good idea what's needed.

Luck to ya!

originally posted by: Mandroid7
Dirty wheel speed sensor I bet.

Blast brake cleaner in it, you can see where its at by looking for a wire that runs to sensor, its near, wheel hubs.

Start and run a couple times to see if it clears, or sm1 will need to clear the fault code with a obd2 reader.

Added...super common in cars in snow, ice and salt.

Good suggestion. How do you apply the break cleaner? Do I have to take out the wheel covers?

a reply to: Trueman

Follow the electrical wire to the hub in the wheel, turn the wheel inward and look at the whole hub, brake assy from the back.

Its the only thing with a wire to it hub assembly.

Are you in a snowy area?

a reply to: Trueman

They are behind the wheel hub. Jack the vehicle and remove the front wheels. Where your brakes mount the the steering knuckle , on the engine side usually on top side of the cv shaft/axle. It will have two wires into a plug harness. Many times the wire has a keeper on the strut, you can find it there and trace it to the axle.
Fyi - those are not standard copper wires, so don't try to splice them if damaged. Order a new abs/traction control wire assembly. Sometimes called a pigtail or whip depends on who you talk to.

The other cause can be a damaged exciter ring on the cv/axle itslef. That's the toothed gear that the sensor reads. If it's chipped or cracked, or even filled with ice- it won't get a signal. If that's the case you have to swap the cv/axle.

And my first thought wouldn't likely be wheel speed sensor, as the traction control and ABS likely use the same sensor.
And wouldn't be likely to set a check engine light.

Maybe vehicle speed sensor?

a reply to: caterpillage

Many vehicles use the abs sensor in conjunction with the output shaft sensor on the transmission for vehicles speed. The body control module reads that and from the ecu to determine what's going on.

originally posted by: Mandroid7
a reply to: Trueman

Follow the electrical wire to the hub in the wheel, turn the wheel inward and look at the whole hub, brake assy from the back.

Its the only thing with a wire to it hub assembly.

Are you in a snowy area?

We had snow last weeks. You're right

So I don't need to lift the car?

originally posted by: Hewhowaits
a reply to: Trueman

They are behind the wheel hub. Jack the vehicle and remove the front wheels. Where your brakes mount the the steering knuckle , on the engine side usually on top side of the cv shaft/axle. It will have two wires into a plug harness. Many times the wire has a keeper on the strut, you can find it there and trace it to the axle.
Fyi - those are not standard copper wires, so don't try to splice them if damaged. Order a new abs/traction control wire assembly. Sometimes called a pigtail or whip depends on who you talk to.

The other cause can be a damaged exciter ring on the cv/axle itslef. That's the toothed gear that the sensor reads. If it's chipped or cracked, or even filled with ice- it won't get a signal. If that's the case you have to swap the cv/axle.

It sounds sorta expensive ?

a reply to: Trueman
I actually go to forums like Automotiveforums.com to find answers like that....

a reply to: Hewhowaits

Right, so if a wheel speed sensor is at fault, it would likely set an abs light too. I would think

a reply to: Trueman

It's actually not that bad. You probably just have crud stuck in the exciter ring. Rust falls in there all the time, sometimes it becomes magnetized and just needs cleaned out. If you have ice built up that can do it too.
The wire harnesses are usually about 15-20$ and just plug in on both ends. The axle can be a pain in the ass if your not equipped with an impact wrench and large sockets to pull the axle and drop the strut, etc....

I have an axle in my mudroom right now that's going in my jeep. If you want I'll upload a pic of the exciter ring so you know what it is.

a reply to: Trueman

The hub will have a either cog or smooth shapped drum on it, the sensor is air gapped to sense the spin.
The computer calculates the speed variation to do 2 things, let off power when the drive wheel spins faster than the other, and to release the brakes when they lock up. If the sensor moves too far away from drum, or snow packs in sensor, or wire to sensor comes loose, your traction control and anti lock brakes won't function.

You should be able to get at it by turning wheel inward, from the back, just use a straw and spray between sensor and drum, like you are cleaning the face of the tiny sensor.

The sensor is the only thing with a wire going to it. Do all 4 wheels, do front first so you can id what you are cleaning easier.

The second issue with these things is the air gap or gap between sensor and drum. Aquick and dirty way to set the gap w/o a feeler gauge is to loosen sensor bolts, place cereal box cardboard between, push sensor toward drum lightly while you tighten, then pull out cardboard.

Not certain the obd2, which they do for free at autozone can pinpoint a wheel speed sensor to the specific wheel, but worth a try.

Individual sensors can be tested for damage if gaps are good, sensors clean, wires to them are good, by running an ohm tester across the prongs on the sensor when unplugged and on the car. You would need to google specific resistance for the test, but you will know right away if it is a faulty sensor, they can crap out from radiant heat when parked from brake heat.

Good luck, Id start with obd2, try and pinpoint which wheel, then clean, check gap, and wire, retest.then go to ohm test.

You need to fix it though because you antilock is now disabled, and it can lock up tires now.
The traction things not that important, but helps on ice.

a reply to: caterpillage

Yes, it would. Also ice build up on an axle can knock it out of balance, which can upset the traction control sensors.

a reply to: Trueman

Yeah, I got a hundo on snow or ice on it.

No lift just turn wheel inward, access from behind.

For back, reach behind wheel. Get a can that has a straw on it and spray the gap, whipe excess cleaner off plastic stuff if you can.

I'm from Iowa, I've delt with this too many times in snow and with my offroad jeeps and mud.

Good luck

Oh yeah, if its cog shapped, do the drums teeth, some of those work off the shape, not a magnet, so if the shapes smooth from ice pack vs toothed, it wont read.

a reply to: Trueman

I have a Lexus. When mine came on at the same time it was the charcoal canister. Pain in the butt to fix due to it's location.