Traction Control Light and Check Engine Light On- [Explained!!]

The traction control light and check engine light might be on if the TCS system malfunctions. It might also be turned off. A faulty wheel speed sensor or improper tire pressure might also cause it. Also, the lights will be on if your engine misfires or the transmission shift is harsh.

A continuous illuminated traction control and check engine light means there’s a problem somewhere in your vehicle. 

So, why are the traction control lights and check engine light on?

But, this is only a brief summary. Stick with us till the end to know everything in as much detail as possible. 

What Do TCS Light  And Check Engine Light Mean?

The TCS light is a system light relating to the traction of your vehicle. The TCS system detects your vehicle’s tire friction loss and displays it using the TCS light. If there’s any problem regarding the TCS system in your car, the light will stay on.

Check Engine Light On

The check engine light represents a warning that there’s a problem with your engine. It can also be triggered due to a malfunctioning ignition, fuel, exhaust, or emission system. Your onboard diagnostics system detects these malfunctions. 

It’s not unusual to see both the TCS and check engine lights illuminated simultaneously. But, you might see the check engine light flashing and the traction control light on. 

If the check engine light is flashing, it means the problem is more serious than normal. Mostly, it indicates unburned fuel and misfiring in the exhaust system. As soon as you see it flashing, immediately address the problem. 


The TCS light indicates a problem regarding your vehicle’s traction. A check engine light represents a problem in the ignition, fuel, exhaust, or emission system.

Traction Control Light and Check Engine Light On- Common Causes and Solutions!

There are some common causes for the traction control and check engine light to come on. First, let’s get to know about them.

Loose Gas capTighten or Replace The Gas Cap
Faulty engine control unit ECUContact Mechanic
Improper tire pressureAdjust tire pressure
Faulty wheel speed sensorsReplace the wheel speed sensor
Engine misfiringCheck error codes and cylinder temperature
Fix air and fuel misfire
Address electrical and mechanical misfire
Variable valve timing VVT switch and solenoid failureChange Engine Oil
Clean or Replace Solenoid
Replace Valve Body Assembly

Now, let’s discuss these reasons in detail. 

Reason 1: Loose Gas Cap

With a loose gas cap, the fuel vapor will get out of the fuel tank. This vapor will cause an error in your emission system. It’ll also allow foreign particles to get inside the fuel tank. Thus, it might cause the TCS and check engine light to turn on.

Solution: Tighten or Replace The Gas Cap

Take a flashlight and inspect if the gas cap is damaged. If it doesn’t look cracked or damaged, hand tighten it until you hear a clicking sound. It means the gas cap has settled in. 

But, if it’s still loose, you’ll need to replace the gas cap. It probably means that the seal in your gas cap is broken.  

Just remove the old gas cap and replace it with a new one. Be sure that it matches the model of your vehicle. During this, check if the seal between the gas cap and filler tube is ok. If it’s not, you can use a sealant to repair it.

Reason 2: Faulty ECU

If you have a faulty ECU, the engine will lag or misfire. It might not even start at all. Thus, the check engine light might come on. The ECU also monitors the TCS. Thus, a faulty ECU causes a problem in the TCS and makes the TCS light illuminate. 

The ECU may get damaged due to water getting into it. While upgrading the ECU, power fluctuations might corrupt the data. It might even get faulty just due to the end of life of the system.

Solution: Contact The Mechanic

If there’s a problem with your ECU, you should take it to the mechanic. He’ll be able to say if the ECU can be fixed or needs to be replaced. Depending on the repair it might cost you about $300-$750.

Reason 3: Improper Tire Pressure

If the tire pressure isn’t adjusted properly, you won’t get proper traction. It’ll be harder to operate the vehicle and the tire will be damaged. The tread will wear out. Thus, the water will get trapped rather than flowing through the tread design.

Also, the fuel efficiency will decrease. For every 1 psi drop in pressure, the gas mileage drops about 0.1 to 0.2%.

This issue will also cause both the lights to illuminate.  

Solution: Adjust Tire Pressure

Improper tire pressure is bound to happen with everyday use. And, it can be fixed by simply readjusting the tire pressure. So, how to readjust my tire pressure?

First, find what’s the recommended tire pressure of your vehicle from the manual. It can also be found in the fuel cap or driver’s door. Set the air machine according to the pressure. Connect it with your tire and it will automatically adjust the tire pressure.

Be sure to check all the tires for improper pressure. Repeat the same process for each tire with improper pressure.

Reason 4: Faulty Wheel Speed Sensors

Wheel speed sensors measure the rotational speed of your car’s wheel. 

The ECU then uses this information to adjust the vehicle’s speed. So, if the sensor is bad, this whole process breaks down. Thus your vehicle won’t be able to operate correctly and both lights will come on.

Solution: Replace Wheel Speed Sensors

If the sensors are bad, the right solution is to replace them. 

First, disconnect the battery terminals and locate where the sensor is. Disconnect the connector for the sensor and remove the sensor cable clipped into the car body. Then, you can unbolt the sensor and simply pull it out. Lastly, install you new sensor.

You can also watch this video for a detailed guide: How to Replace ABS Wheel Speed Sensor – EASY!

Reason 5: Engine Misfiring

When your engine misfires, the air, and fuel mixture gets compromised. Thus, your engine may start and stop suddenly. The most common reasons for engine misfiring are bad spark plugs, ignition coils, and vacuum leaks.

When the engine misfires, the check engine light along with the TCS light will come on. This misfiring engine jolts up the vehicle and affects the stability. The traction control system can pick up this change. Thus, the TCS light comes on. 

Solution 1: Replace Spark Plugs

If the spark plugs are bad, just replace them with new ones. Be sure to adjust the gap of the spark plug according to your vehicle model. You can find it in the owner’s manual. You can use a spark plug gapper to adjust the gap.

Solution 2: Clean or Replace the Ignition coil

Sometimes, you can fix the ignition coil by simply cleaning it a bit. But if it’s gone completely bad, you’ll have to replace it. So, how to fix a bad ignition coil? First, get these tools to work with:

  1. Wrench and socket
  2. Screwdriver
  3. Allen wrench
  4. WD40 cleaner
  5. Cloth

Now, follow the process below: 

Step 1: Open the hood and take off the engine cover by unscrewing it. On some vehicles like Toyota, the symbol might be the screw. There are also other Allen wrench screws which you’ll have to remove using an Allen wrench.

Step 2: Now, unscrew the ignition coil with a wrench and socket. Then, take off the wiring harness by unclipping it. Then, you’ll be able to easily pull out the cylinder.


Step 3: To check if the cylinder is bad, replace it with another one in your engine. Then scan the vehicle with your OBD2 scanner. If the fault code shifts to the new position you’ve put the cylinder in, it’s bad.

Step 4: If the coil is damaged, take a new cylinder instead of fixing the older one. Use the exact cylinder that was used before. Put it in the engine and attach the bolt. Then, connect the wiring harness. 

Step 5: Reattach the engine cover by screwing it in.

Sometimes, you can’t locate the exact cylinder that’s causing a problem with an OBDII scanner. In that case, you’ll have to check every cylinder. 

Solution 3: Repair Vacuum leaks

Vacuum leaks in your engine allow excess air into the engine. Thus, the air and fuel ratio gets unbalanced. 

But, they can be quite easily fixed using silicon tape. If you have a vacuum leak, tape it firmly. It instantly fuses with the vacuum and can handle about 25000 PSI pressure. Thus, you won’t hear any leaking sound from the vehicle.

Reason 6: VVT Switch and Solenoid Failure

VVT (Variable Valve Timing) system controls the timing of the intake and exhaust valve openings. Thus, the engine operates smoothly. But, without some basic maintenance, it fails. 

For example, if the oil is dirty, the VVT solenoid will be clogged. Lack of engine oil can also cause VVT system malfunctions. They might also affect the VVT switch.

Sometimes, there might be leaks in the valve body assembly. Thus, the oil pressure doesn’t reach the variable cam assembly and the car runs poorly. Since it’s an engine issue, the check engine light comes on. 

Also, as the engine can’t perform properly, it’s unable to provide the wheels with enough power. Thus, there could be a loss of traction and the TCS light can come on. 

Solution 1: Change or Refill Engine oil

If the engine oil is too dirty, you’ll have to change it. You can watch this video for instructions: 

If the engine oil level is low, you won’t have to drain it first. Just add some engine oil to the appropriate level.

Solution 2: Clean or Replace Solenoid

If the solenoid is clogged, you’ll have to clean it. So, how to clean VVT solenoid? First, you’ll need these tools: 

  1. Socket
  2. Rubber Mallet
  3. Prybar
  4. Cleaner

Now, follow the guide below: 

Step 1: First, remove all the ignition coils. Disconnect the tabs holding it and remove the bolts with a socket. Then, pull out the ignition coils. 

Step 2: Now, unplug the VVT solenoids by disconnecting the tabs again. Pull the wire out of the studs. Disconnect all the connectors necessary to remove the wiring harness from the valve cover. 

Step 3: Using a socket, remove all the bolts that hold the valve cover in place. Then, remove the cover by gently using a pry bar. You can hammer the cover with a rubber mallet gently and pull it to loosen it.

Step 4: Get the wiring out of the way and remove the cover. 

Source: TRQ Youtube

Step 5: Remove the bolts of the solenoids with your socket. Then, you can just pull out the solenoid. 

Step 6: Now, take a 9V battery and some wires. Connect the solenoid’s points with the wire but be sure that they don’t touch each other. Connect one wire with a battery terminal.


Step 7: When you connect the other wire to the battery, it’ll start to open and close. Now, take your cleaner. Open the solenoid and spray it into the hoses. You’ll see dirt coming out of the solenoid. Be sure to spray everywhere while turning it on and off.

You can also take some cleaner in a cup and dip the solenoid into it. Then, open and close the solenoid to get the dirt off. 


Step 8: Now take some engine oil and pour it while turning the solenoid on and off.


With that, your solenoid should be cleaned. It should work properly now. Although, if your solenoid doesn’t function at all, you’ll have to replace it. After checking the solenoid in step 7, take a new one that matches your vehicle. 

Then, put everything back in place. Bolt in the solenoid and reattach the valve cover. Connect all the wirings you previously disconnected. Then, check if it works properly.

Solution 3: Replace Valve Body Assembly 

If the valve body assembly is bad or leaking, you’ll have to replace it. So, how to replace valve body assembly? 

It’s pretty easy. Just remove the bolts of the assembly using a socket. If you can’t see the bolts properly, feel it by hand and remove them. Then, you can take out the assembly and replace it with a new one. Attach the new assembly with the bolts as they were.

TCS and Check Engine Light for Specific Models

All of the problems above are generalized. But, some problems are more common to a particular model. Thus, here we have talked about four specific models. Let’s see why the TCS and Check engine light illuminate in them:

ModelProblem Solution
Chevy CruzeGasket leakUse sealant or replace gasket
Nissan SentraMalfunctioning ABS and TCS moduleContact mechanic
TacomaLoose gas capTighten or replace gas cap
CamryFaulty steering angle sensorReset or replace sensor

Gasket leak

Traction control light and check engine light on chevy cruze are commonly caused because of a gasket leak. A gasket leak will cause the engine to lose compression.

Solution: Use Sealant or Replace the Gasket

If the leak is small enough, you can use a sealant. Here’s what you’ll need to do:

Step 1: Place a drain pan under your car. Then, remove the bolts of the gasket and suck out some of the coolants. 

Step 2: Then, take your preferred sealant and apply it to the leak. Depending on your sealant, you may have to wait 5-10 minutes for it to dry. Then, add the coolant you sucked out and attach the bolts. And you’re done!

If the leaks are too big, the gasket needs to be replaced. But replacing a gasket can be quite complex for a DIY project. If the gasket needs replacing, there are a lot of other things that also need fixing. Thus, it’s advised to contact a professional.

Malfunctioning ABS and TCS Module

Traction control lights and check engine lights on nissan sentra also have a common reason. It is a faulty ABS and TCS module.

Solution: Reset and Contact the Mechanic

Repairing a faulty ABS and TCS module is the job of the proper authority. So, you should hire a professional. But, before that, you can reset the modules once. If the problem is something temporary, it should go away with a reset.

Loose Gas Cap

Tacoma traction control light and check engine light on might indicate a loose gas cap. We’ve already mentioned how you can address this problem.

Faulty Steering Angle Sensor 

Finally, let’s talk about 2011 camry traction control light and check engine light on. In this case, it’s common to face a C1231 fault code. This represents a malfunction in the steering angle sensor. 

Solution: Reset or Replace Sensor

First, you can reset the sensor. It should fix any temporary problems. So, how to reset steering angle sensor? Follow this guide:

Step 1: Park your car and turn the engine off. Then, remove the terminal cables from the battery using a wrench. 

Step 2: Locate the sensor. You should find it on the top of the steering column. Take a wrench and loosen the nut that secures the sensor. 

Step 3: Pull away the sensor and disconnect its connector. Then, connect it again.

Step 4: Secure the sensor back in place by tightening the nut. Finally, reconnect the terminals and start the vehicle.

If resetting didn’t do the trick, you’ll need to replace the sensor. After disconnecting the sensor (Step 3), connect a new sensor in its place. Then, continue the same process. Make sure that the new sensor fits your model. 

Check Engine Light On- Specific Reasons and Solutions!

There are some specific reasons for which only the check engine light illuminates. Here, we’ve listed them out:

Faulty Oxygen SensorReplace oxygen sensor
Faulty Exhaust SystemFix exhaust leak
Clean or Replace catalytic converter
Low or Bad Engine OilRefill or replace engine oil

Now, let’s explain them. 

Reason 1: Faulty Oxygen Sensor

Since, the oxygen sensor is in the exhaust system, it can get contaminated. You’ll notice a rotten egg smell of sulfur. The fuel efficiency will be significantly reduced. There’ll be a high level of emissions. Thus, the check engine light will come on.

Solution: Replace The Oxygen sensor

If the Oxygen Sensor is bad, you’ll have to replace it. You can watch thi video for specific guidelines: How To: Change O2 Sensors (Oxygen Sensor)

Reason 2: Faulty Exhaust System

If your exhaust system is faulty, You will hear excessive exhaust noise. The engine will misfire and the acceleration will be slow. Mostly it happens because of an exhaust leak or a faulty catalytic converter.

Solution 1: Fix exhaust leak

If you have a leak in your exhaust system, fix it first. Usually, leaks happen between the two flanges where the exhaust pipes meet. They might become too rusty and corroded. Thus, they start to leak. 

Here, you can watch this video on how to fix the exhaust leak:

Solution 2: Clean or Replace Catalytic Converter

If your catalytic converter isn’t fixed quickly, it’ll keep on reducing your engine’s performance. At one point, the engine will shut down. So, how to fix your catalytic converter? 

You can clean or replace it. If you can hear rattling sounds from your converter, just replace it. But, if that’s not the case, cleaning it should do the job. You can watch this video for a detailed guide: 

Reason 3: Low or Bad Engine Oil

If the engine oil is bad or low, the engine will overheat. You’ll get less efficient performance. The oil will look and smell burnt. Thus, it’ll trigger the engine light. 

Solution: Refill or replace engine oil

If the engine oil is low, you’ll just have to refill it. Although, if the oil is bad, replace it with new engine oil. (1)


Is It Ok to Drive with Traction Light On?

Yes, it’s ok to drive with a traction light but only under certain conditions. You have to make sure the anti-lock braking system light and red brake-warning light aren’t on. If they’re on, your whole braking system might have failed. Thus, you’d be much more prone to any accidents.

Is ABS and Traction Control The Same Thing?

No, the ABS light and the Traction control aren’t the same. The ABS helps to ensure that your wheels stop spinning while you’re braking. On the other hand, traction control does the same thing but while accelerating. It has an added solenoid valve for each brake circuit of the drive wheel. 

How to Know If My Check Engine Light is Serious?

You can know if the check engine light is serious by identifying the color of the light. When the light is blinking or illuminating, it’ll typically show three colors. They are yellow, orange, and red. If the blinking light is red, then there’s a serious problem that needs to be addressed. 

Bottom Line!

We tried our best to explain why’s your traction control light and check engine light on. Still, here’s a parting tip for you. Before you diagnose problems, start with a reset and see if the lights go away.

Thanks for going through the whole article.

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William Baldwin

This Is William Baldwin, The Founder & Managing Editor of this website. Me and my team share automotive tips, tricks, and news

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Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at with a passion for the automotive industry.