What does it mean when the check engine light and trac off light comes on?
When the check engine light (CEL) and the TRAC OFF light come on together, it usually indicates a fault detected by the engine management system that may also affect the vehicle’s traction control system. You should diagnose the issue promptly and avoid hard driving.
What these lights indicate
The Check Engine Light signals that the vehicle’s on-board diagnostics (OBD-II) have stored one or more trouble codes pointing to an engine, emission, or fuel/air system issue. The TRAC OFF light (traction control off) means the car’s traction/stability control system has been disabled or is operating in reduced mode, often because a fault has been detected in the ABS, wheel‑speed sensors, or related control modules. When both lights appear, it can mean a fault that affects engine performance, emissions, or vehicle stability, or a fault that triggers protective limp‑mode behavior in some cars. The exact meaning can vary by make and model, so consulting the owner’s manual or a dealer/technician familiar with your vehicle is wise.
Common causes when both lights appear
These are the kinds of issues that commonly trigger both the CEL and TRAC OFF lights. They span engine performance problems and traction control/ABS faults.
Engine and emissions-related causes
- Misfire in one or more cylinders (bad spark plugs, ignition coils, or wiring)
- Faulty oxygen (O2) sensors or air-fuel sensors
- Mass airflow (MAF) sensor problems
- Vacuum leaks or dirty/blocked fuel injectors
- Catalytic converter or exhaust system issues
- Malfunctioning crankshaft or camshaft sensors
Engine-related faults often trigger the CEL and, depending on how they affect performance, can cause the traction control system to intervene or disengage to protect the drivetrain.
Traction control/ABS-related causes
- Wheel speed sensor faults or wiring problems
- ABS hydraulic pump or modulator failure
- Electronic stability/traction control module faults
- Low battery voltage or alternator issues that affect control modules
- Software/communication faults between engine, ABS, and stability systems
Traction control issues can light TRAC OFF independently, and when paired with a CEL, may point to a broader fault in the vehicle’s electronic control systems.
What to do if the lights come on
If you see both lights, take these prudent steps to reduce risk and gather information for diagnosis.
- Safely pull over if you’re driving and the car feels abnormal (loss of power, poor handling, strange noises).
- Check for obvious problems such as fluid levels (oil, coolant) and tire pressures; ensure tires are properly inflated and in good condition.
- Obtain the trouble codes with an OBD-II scanner. Many auto parts stores offer free code reads; you can also use a personal scanner if you have one.
- Note the codes and any accompanying symptoms (misfire, rough idle, hesitation, poor acceleration) to share with a technician.
- Limit driving speed and avoid hard acceleration or towing until you know the issue, especially if there is loss of power or braking concerns.
- Schedule a diagnostic service with a mechanic or dealership to pinpoint the cause and address it properly.
Code readouts and symptoms guide the next steps; in many cases, a quick repair or parts replacement can prevent further damage to the engine or drivetrain.
When to seek immediate help
Seek urgent assistance if you experience any of these:
- The car loses power suddenly or stalls and won’t restart
- The CEL or TRAC OFF light flashes or you hear loud noises, knocking, or banging
- There is a strong fuel smell, smoke, or visible fluid leak
- Dashboard indicators indicate overheating or severe engine trouble
In these cases, have the vehicle towed to a service facility rather than continuing to drive, to avoid potential damage or unsafe driving conditions.
Summary
The simultaneous activation of the check engine light and TRAC OFF usually signals a fault detected by the engine control and traction/ABS systems. Causes range from engine misfires and sensor problems to ABS/wheel‑speed sensor faults. Start with a code read, inspect obvious issues, and consult with a qualified technician to diagnose and repair the underlying problem. Prompt attention can prevent more extensive damage and keep the vehicle safe to drive.
How to fix Toyota Trac off and check engine light on at the same time?
Two open the hood. Three disconnect the negative black battery cable for 2. Minutes four reconnect it and start your car this resets your vehicle's onboard computer ECU. And might clear those lights.
How much does it cost to fix trac off issues?
The average cost for a Traction Control Switch Replacement is between $130 and $158. Labor costs are estimated between $60 and $88 while parts are typically priced around $70.
Why did my check engine light and traction control light come on at the same time?
Your check engine and traction control lights likely came on at the same time because a single powertrain issue is triggering both warning systems. Common causes include faulty wheel speed sensors, engine misfires, or problems with the ABS system. It's important to have a mechanic diagnose the problem to ensure safety, as the traction control system may fail.
This video explains common causes and solutions for the check engine and traction control lights: 59sVehicle FreakYouTube · Nov 1, 2023
Potential causes
- Faulty wheel speed sensors: These sensors are used by both the check engine and traction control systems, so a bad sensor or its wiring can trigger both lights.
- Engine misfires: A misfire can be caused by issues like bad spark plugs, which can disrupt the engine's performance and cause the traction control system to activate.
- Powertrain issues: A general powertrain fault can trigger the check engine light, which then automatically activates the traction control light as well.
- Low tire pressure: Uneven tire pressure can confuse the traction control system and cause both lights to come on.
- Problems with the ABS system: Because the ABS and traction control systems are interconnected, a fault in the ABS module can cause both warning lights to illuminate.
- Loose gas cap: A loose or bad gas cap can cause a fuel system leak, which may trigger a variety of warning lights, including the check engine light.
What to do now
- Check the gas cap: Make sure your gas cap is tightened securely. If it was loose, tighten it and see if the lights turn off after a while.
- Inspect tire pressure: Check all four tires to ensure they are properly inflated. If one or more are low, inflate them to the correct pressure.
- Scan for diagnostic trouble codes (DTCs): The most accurate way to determine the cause is to use an OBD-II scanner to read the specific diagnostic codes. Many auto parts stores will scan for free.
- Get a professional inspection: Because the traction control system is a critical safety feature, it's best to have a qualified mechanic diagnose and repair the issue, especially if the problem persists or if you experience any brake issues.
Can I drive with trac off light on?
Yes, you can generally drive with the "TRAC OFF" light on, but you should do so with caution, especially in slippery conditions like rain or snow. The light indicates the traction control system is disabled, meaning your vehicle won't have electronic assistance to prevent wheel spin and loss of traction. If the light comes on along with the check engine light, it suggests a more significant issue, and you should take the vehicle to a mechanic to have it diagnosed and repaired promptly.
If the light is on because you pushed the button
- Intentional disabling: You may have pressed the "TRAC OFF" button to get unstuck in snow or mud, and this is a normal function.
- To fix: Simply press the button again to reactivate the system.
If the light came on by itself
- Dangers: The traction control system will not be operating, which can lead to a loss of control on slippery roads. If the light comes on along with other warning lights like the check engine or ABS light, it indicates a potential malfunction with a more serious underlying problem.
- What to do:
- Drive more cautiously and at a slower speed.
- Avoid aggressive driving.
- Get the vehicle checked by a mechanic to determine the root cause and have it repaired.
- If the check engine light is also on, have an auto parts store or mechanic use an OBD-II scanner to read the diagnostic trouble codes (DTCs) to identify the specific problem.
