Reasons for Lexus Trac Off Check Engine Lights: A Guide

Modern luxury cars like Lexus incorporate responsive dashboards of warning lights to inform drivers of hidden issues with the automobile system.

Learning the message behind each light is a must – unless you wish premature death for your car! 

And as many novices are still confused with the Lexus Trac off check engine light, I will tackle this burning issue once and for all. Keep scrolling for more advice.

What Is The Meaning of Lexus Check Engine Trac Off Light?

lexus trac off check engine
Lexus Check Engine Trac Off Light

Before I dive further, please note that the Check engine and Trac Off lights are not identical.

  • Lexus Trac Off Light: These lights are closely connected with Lexus’s traction control systems. Whenever these systems are accidentally turned off or encounter severe problems, the lights will flicker to warn clueless drivers.

Long story short: Trac Off turned on = Traction control failure.

  • Check Engine Lights (CEL): CELs are indicators of your car’s emissions and operation system, implying engine troubles that need immediate addressing.

The best course of action to handle these lights is to contact experts and have your car diagnosed right away.

All in all, they are two completely different lights. So why do professionals often lump Check Engine and Trac Off light Lexus together? 

Simple: traction control and engine operation are tightly intertwined.

Traction failure destroys engine power – and vice versa. As a result, problems with either traction or engine often trigger BOTH Check Engine and Trac Off light on Lexus simultaneously.

Why Is The Lexus Trac Off/ Check Engine Light Turned On? Common Causes

What happens behind a flickering Lexus Trac off/Check engine light? 

Notorious causes for Check engine/Track off light Lexus being turned on are broken MAF sensors, loose gas caps, bad oxygen sensors, spark plugs, and catalytic converters.

Broken Oxygen Sensors

It’s not exaggerating to say O2 sensors are the most common culprit behind the blinking check engine and traction control light.

Installed in the car’s emission system, these sensors are designed to double-check the fuel-burning process and guarantee peak engine performance.

And together with the catalytic converter, they manage and control emissions within safe territories.

Unfortunately, oil and ash stain the sensors over time, reducing their razor-sharp ability to monitor the oxygen and fuel mix.

Even the A/C system will get destroyed during the process, triggering the Trac off and Check engine light Lexus!

To fix or replace the sensors, go to any local repair shop in your neighborhood. The priciest service in my town only costs me 200 bucks at best (both labor and parts counted).

However, those confident in their skills can save some bucks by doing the replacements themselves.

Purchase the sensors online, then check the manual for detailed instructions and guidelines.

Faulty or Loose Gas Caps

Sometimes, the reason behind flickering light is as simple as a loose cap. You might think it’s silly; how can something as harmless as a cap wreak so much havoc on your Lexus? 

Here’s how: The loose (or damaged) caps let vapors in the vacuum leak out and throw off the entire emission system.

Your car suffers from decreased performance and efficiency, eventually losing all engine power! 

Fix tips are simple: inspect the cap.

  • If it is loose, tighten the cap and check the traction light again to see whether it has turned off.
  • If it’s damaged, purchase replacements at auto stores for $5-$10.

Failing Catalytic Converter

Have you ever wondered how Lexus emissions are reduced? That’s right; the catalytic converters shoulder most of the hard work.

They convert dangerous gasses (ex: carbon monoxide) into non-toxic compounds, extending the car’s lifespan as a result!

A catalytic converter is expected to last as long as the car itself – more than 100,000 miles (equivalent to 10 years or so).

Nevertheless, natural tear and wear or forceful collisions might bring the device to its limit sooner than expected. Remind yourself to look out for these symptoms:

  • Strange smells
  • Decreased performance
  • Reduced fuel efficiency

Sadly, repair costs are by no means cheap. Even the least-demanding one starts at $2000.

And DIY replacements to cut the charge is out of the question: unless you yourself are experienced, it would be best to leave the job to trustworthy experts.

Malfunctioning MAF (Mass Air Flow) Sensor

Air filters neglected for too long could put your MAF sensors and exhaust system at big risk.

And without MAFs, how can your Lexus inject proper fuel levels into the tank and increase overall performance? 

Worse, the sensors might even transfer inaccurate data due to this malfunction, causing increased emissions, car stalling, and bad gas mileage.

Your best bet is to reset the MAF sensor or replace it (and remind yourself to do so at least twice per year!).

The only problem is the price – $200, labor counted. Thankfully, there’s a way to reduce it a little: have the technician perform other repairs, while you replace the filters by yourself at the shop.

Problematic Spark Plugs

A typical spark plug can last from 30,000 to 50,000 miles, sealing the combustion chamber to provide enough spark for fuel ignition in your car engine.

So what would happen if they went bad? Even the most oblivious driver can notice these signals:

  • Misfiring plug wires (or ignition system issue)
  • CELs/Traction Off turned on
  • Jolting sensations during your acceleration

Still, if I have to stick with the lesser devil, I would rather it be spark plugs. They are ridiculously cheap than other parts and super easy to uninstall.

The starting price is $10, and DIY replacements are totally within reach – thanks to tons of instructional guides on the Internet!

What To Do To Troubleshoot The Lexus Trac Off/ Check Engine Light?

lexus check engine trac off
Troubleshoot The Lexus Trac Off

At first glance, troubleshooting seems like a no-brainer: find out which part goes wrong and fix it! 

Unfortunately, visible symptoms of malfunctions are not always that observable, which is why other more straightforward methods will be needed.

This section will detail how to locate the root cause of the problem within minutes.

Purchase OBD Readers

I bought a standard OBD reader for $60, easily accessible at every auto store and even Walmart.

$60 might seem like a fortune, but think about it: pulling your Lexus to a shop for first checks already costs at least $75 – and the diagnosis hasn’t even started!

Looking at it that way, OBD readers are obviously a good investment.

Here’s a quick rundown of how the device works:

  • Your Lexus has an onboard computer to receive different automotive inputs. Once something is wrong with the input (meaning a part is malfunctioning), the computer will record that issue to turn the service lights on.
  • Once plugged in, the reader will display all error codes recorded by the computer. Most of the time, they are generic codes found in all car models (not just Lexus), though I still do note some exceptions.

Scan For The Diagnostic Trouble Codes

Identify the side dashboard, then look below its lower edge. There will be a shaped trapezoid port – where the reader is supposed to get plugged in.

Turn off the ignition and engine, then plug in your OBD reader. Once done, switch on the key (but do not start the engine), and press “Scan” to see the results.

The display screen on your scan tool will show all error codes stored inside the computers. Scroll through them (if there’s more than one code) and jot everything down.

Search The Meanings Of The Codes

So what to do next? Be grateful for the invention of the Internet: thousands of threads or forums on the same issue have existed for years, filled with all the relevant information you need.

More specifically, the codes you have written down are likely to occur with other cars as well.

Your only job is to search those codes on popular platforms (Google, Bing, Yahoo, etc.) and figure out their meanings.

Suppose the reader displays the P0496 code; here is what you can enter in the search bar: “Lexus OBD P0496”.

Adding vehicle years is also welcomed – though not entirely necessary.

The structural cores of these cars will likely remain the same over time: for instance, fixes for 2005 models can be applied to 2008 ones or vice versa.

Locate The Problematic Part. Uninstall and Replace It.

Now that you have figured out the faulty compartment thanks to the help of Internet fellas.

What to do if you find out O2 sensors are the start of all problems – but do not even know where they are installed? 

Again, I always trust Internet searches to do their magic. You can find detailed diagrams of even the oldest vehicle there – let alone luxurious ones like Lexus.

And it would be even better if you didn’t throw away your old instruction manuals!

Once you have properly tracked down the broken parts, the rest of the replacement is a piece of cake.

Erase The Codes

Have you already fixed the issues? Good. Now plug the OBD readers back in.

  • Press “Erase” and hold it for a few seconds.
  • When the display screen changes, hit “Erase” once more to confirm.
  • The code should disappear now, turning off the lights during the process.

Important Note:

  • For those fixing their cars to pass smog checks, it would be best to drive the vehicle for at least 24 hours before bringing it to testing.

Experienced technicians can easily tell whether the codes have recently been deleted; they will charge you $24.95 and ask you to return next time.

  • Traction off/ Check engine lights flickering during the test will be automatically rated as “Failed”. Ensure they have been turned off before the inspection.

How to Prevent Blinking Check Engine/Trac Off Lexus Light? Tips for Car Maintenance

lexus es 350 check engine light and trac off
Way To Prevent Blinking Check Engine

Do you know the best way to keep these lights turned off forever? That’s right; frequent engine and car maintenance is the key.

Every few months, make sure your precious Lexus is properly serviced by: 

  • Changing oil monthly
  • Inspect the fluids (steering/ transmission/ brake fluid, coolant, engine oil)
  • Replacing air filters twice a year
  • Upgrading braking pads
  • Washing the car off road salts and dirt


The reasons and symptoms behind a flickering Lexus Trac off/ check engine light is no mystery, and most of the repairs come with a hefty price.

So you must pay more attention to your car on a regular basis for the sake of your car and your pocket alike.

Have it serviced and maintained as often as you can, and don’t forget to write to me should you want more support.

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