The check engine light on your dashboard is a warning that something is wrong with your vehicle. It can be a frustrating experience, but it doesn’t necessarily mean that you need to take your car to the mechanic right away. In some cases, you can clear the check engine light yourself using a code reader or scanner. This is a simple and inexpensive way to troubleshoot the problem and get your car back on the road.
To clear the check engine light with a scanner, you will need to purchase a code reader or scanner. Code readers are available at most auto parts stores and online retailers. Once you have a code reader, you can follow these steps to clear the check engine light:
1. Connect the code reader to the OBD-II port in your vehicle. The OBD-II port is usually located under the dashboard on the driver’s side.
2. Turn on the ignition, but do not start the engine.
3. Follow the instructions on the code reader to retrieve the trouble codes.
4. Once you have the trouble codes, you can use them to research the problem online or consult a mechanic.
5. Once you have fixed the problem, you can clear the check engine light using the code reader.
Connecting the Scanner to Your Vehicle
Step 1: Gather Your Necessary Equipment
Before you begin connecting your scanner to your vehicle, make sure you have all the necessary equipment. This includes the following:
* OBD2 scanner: This is the device that will plug into your vehicle’s diagnostic port and read the trouble codes.
* OBD2 cable: This is the cable that will connect the scanner to your vehicle’s diagnostic port.
* Vehicle Owner’s Manual: This manual will contain important information about your vehicle’s diagnostic port location and other relevant details.
Step 2: Locate the Diagnostic Port
The next step is to locate the diagnostic port on your vehicle. This port is usually located under the dashboard, near the steering wheel. It is a 16-pin connector that is typically black or gray in color. If you have trouble finding the diagnostic port, consult your vehicle’s owner’s manual for specific instructions.
Step 3: Connect the Scanner to the Diagnostic Port
Once you have located the diagnostic port, connect the OBD2 cable to the scanner and then plug the other end of the cable into the diagnostic port. Make sure that the connection is secure and that the scanner is turned on.
Step 4: Turn on the Vehicle
Turn on the ignition of your vehicle, but do not start the engine. The scanner should automatically power on and begin communicating with your vehicle’s computer.
Step 5: Verify the Connection
To verify that the scanner is properly connected to your vehicle, check the display on the scanner. It should show the following information:
| Information | Description |
|—|—|
| Vehicle Make and Model | The make and model of your vehicle |
| VIN Number | The Vehicle Identification Number for your vehicle |
| Connection Status | The status of the connection between the scanner and your vehicle |
Identifying the Code(s)
Connecting the Scanner
1. Locate the vehicle’s diagnostic port, typically situated under the dashboard or in the engine bay near the battery.
2. Connect the scanner’s OBD-II cable to the port, ensuring a secure connection. Turn on the scanner and vehicle ignition.
Reading and Interpreting Codes
1. Navigate the scanner’s menu to launch the “Read Codes” function. The scanner will communicate with the vehicle’s ECU (Electronic Control Unit) and retrieve stored diagnostic trouble codes (DTCs).
2. The codes appear as a series of letters and numbers, such as P0171 or B2143. These codes represent specific faults or malfunctions within the engine or other vehicle components.
Code Format and Meaning
The following table provides a breakdown of the typical code format:
| Character | Meaning |
|---|---|
| First Letter | Type of System (e.g., P for Powertrain) |
| Second Character | Subsystem or Component (e.g., 0 for Fuel and Air Metering) |
| First Number | Subgroup or Category (e.g., 1 for Fuel/Air) |
| Second and Third Numbers | Specific Fault or Component (e.g., 71 for System Too Lean) |
3. Cross-reference the code obtained from the scanner against a vehicle-specific repair manual or online database to determine the exact issue. The manual will provide detailed instructions on how to troubleshoot and resolve the identified fault.
Interpreting the Code(s)
Once you have plugged in the OBD2 scanner and turned on the ignition, the device will automatically read the codes stored in your vehicle’s computer. These codes will appear as a series of numbers and letters, each representing a specific issue or malfunction. Here’s how to interpret these codes:
| Code Type | Description |
|---|---|
| P0xxx | Generic powertrain codes, known to most vehicle manufacturers |
| P1xxx | Manufacturer-specific powertrain codes |
| P2xxx | Generic non-powertrain codes, also known to most vehicle manufacturers |
| P3xxx | Manufacturer-specific non-powertrain codes |
| U0xxx | Communication codes between control modules |
| B0xxx | Body control codes (e.g., airbags, power seats) |
You can refer to an OBD2 code reference guide or consult an experienced mechanic to decipher the meaning of each code. Once you have identified the issue causing the check engine light, you can proceed with repairs or adjustments to resolve the problem.
Resetting the Check Engine Light
Once you have identified the cause of the Check Engine Light, you can reset it using an OBD2 scanner. Here are the steps:
1. Connect the scanner to your vehicle’s OBD2 port. This port is usually located under the dashboard.
2. Turn on the ignition. Do not start the engine.
3. Navigate to the “Read Codes” or “Diagnostics” menu on the scanner. This will display any stored trouble codes.
4. Locate the trouble code that corresponds to the Check Engine Light. This code will usually be a P0XXX code.
5. Select the “Clear Codes” or “Reset ECU” function on the scanner. This will erase the trouble code and reset the Check Engine Light.
Additional notes on clearing trouble codes:
*
Some trouble codes may not be able to be cleared with a scanner. These codes indicate a more serious issue that requires professional repair.
*
If the Check Engine Light comes back on after you have cleared it, it means that the underlying problem has not been resolved. You will need to diagnose and repair the problem to permanently turn off the light.
*
Here is a table summarizing the steps to reset the Check Engine Light:
| Step | Action |
|---|---|
| 1 | Connect the scanner to the OBD2 port. |
| 2 | Turn on the ignition. |
| 3 | Navigate to the “Read Codes” menu on the scanner. |
| 4 | Locate the trouble code that corresponds to the Check Engine Light. |
| 5 | Select the “Clear Codes” function on the scanner. |
Verifying the Repair
Once you’ve made the necessary repairs, it’s crucial to verify that the problem has been resolved before clearing the check engine light. Here’s how to do it:
1. Start the engine: Turn the ignition key to the "on" position, allowing the engine to run for a few minutes.
2. Check the dashboard: Observe if the check engine light remains lit or has turned off. If it’s still on, there may be an underlying issue that requires further diagnosis.
3. Drive the vehicle: Take the car for a short drive under various conditions, such as acceleration, deceleration, and idling. This helps the on-board computer gather data and monitor the system’s performance.
4. Connect the scanner: Reconnect the OBD-II scanner to the vehicle’s diagnostic port.
5. Run a scan: Initiate a diagnostic scan to access the vehicle’s internal computer and verify if the error codes have been cleared.**
The scanner will display a report showing:
- Any remaining error codes that need to be addressed
- Confirmation that the error codes have been cleared
6. Clear the codes: If the scan report indicates that the error codes have been cleared, proceed to clear them using the scanner.
7. Disconnect the scanner: Once the error codes have been cleared, remove the OBD-II scanner from the vehicle’s diagnostic port.
8. Restart the vehicle: Turn off and then restart the car. This action resets the vehicle’s computer and ensures that the check engine light remains off if the issue has been resolved.
Understanding Common Codes
When your check engine light illuminates, it can be a stressful experience, leaving you wondering about the severity of the issue. To decode the messages behind the light, you’ll need a diagnostic scanner. These devices connect to your vehicle’s computer system and retrieve diagnostic trouble codes (DTCs), which provide specific information about the potential problem. Here are some common DTCs and their typical meanings:
DTC P0420: Catalytic converter efficiency below threshold
DTC P0171: Lean air-fuel ratio (bank 1)
DTC P0301: Cylinder 1 misfire detected
DTC P0456: Evaporative emission system leak detected
DTC P0500: Vehicle speed sensor malfunction
DTC P0420: Catalytic Converter Efficiency Below Threshold
The catalytic converter reduces harmful emissions by converting them into less toxic substances. DTC P0420 indicates that the converter is not functioning efficiently, which can lead to increased emissions and potentially failed emissions tests. Common causes include a failing catalytic converter, faulty oxygen sensors, or an exhaust leak.
Causes of DTC P0420
| Cause | Description |
|---|---|
| Failing catalytic converter | The converter may be damaged or clogged, hindering its ability to convert emissions. |
| Faulty oxygen sensors | These sensors monitor the oxygen content in the exhaust, providing feedback to the engine computer. Malfunctioning sensors can lead to incorrect air-fuel mixture ratios and reduced converter efficiency. |
| Exhaust leak | A leak in the exhaust system can allow exhaust gases to bypass the catalytic converter, reducing its effectiveness. |
Preventing Future Check Engine Lights
To prevent future check engine lights, it’s important to take good care of your vehicle and follow these tips:
1. **Regular maintenance:** Follow your vehicle’s maintenance schedule and get regular oil changes, tune-ups, and other services to keep your engine running smoothly.
2. **Use high-quality fuel:** Low-quality fuel can damage your engine and lead to check engine lights.
3. **Drive conservatively:** Aggressive driving can put stress on your engine and transmission, which can lead to problems that trigger the check engine light.
4. **Avoid overloading your vehicle:** Exceeding your vehicle’s weight capacity can strain the engine and lead to check engine lights.
5. **Check your tire pressure regularly:** Low tire pressure can affect your vehicle’s handling and fuel economy, which can lead to check engine lights.
6. **Use the right spark plugs:** Using the wrong spark plugs can cause misfires, which can trigger the check engine light.
7. **Keep your vehicle clean:** A dirty engine or air filter can restrict airflow and cause problems that lead to check engine lights. It’s recommended to clean your engine bay and replace your air filter regularly.
8. **Inspect your vehicle regularly:** Look for any signs of damage or leaks, such as loose hoses or cracked belts. Addressing these issues promptly can prevent them from becoming major problems that trigger the check engine light.
9. **Use a fuel additive:** Fuel additives can help to clean your fuel system and prevent carbon buildup, which can reduce the likelihood of check engine lights.
10. **Consider using a code reader:** If you frequently get check engine lights, consider purchasing a code reader. This device can help you to identify the specific cause of the check engine light, so you can address the issue before it becomes a major problem.
Advanced Diagnostic Tools
Advanced diagnostic tools, such as OBD-II scanners and code readers, can provide more detailed information about the engine’s problem.
These tools can be used to:
- Read and clear trouble codes
- Display live data, such as engine speed, fuel trim, and oxygen sensor readings
- Perform active tests, such as turning on and off solenoids and sensors
- Generate reports that can be used for troubleshooting and repairs
Advanced diagnostic tools can be more expensive than basic code readers, but they offer a wider range of features and capabilities.
Code Reading
Advanced diagnostic tools can read and clear both generic and manufacturer-specific trouble codes. Generic codes are standardized across all vehicles, while manufacturer-specific codes are unique to each make and model.
By reading the trouble codes, you can get a better understanding of the problem and what repairs are needed.
Live Data Display
Advanced diagnostic tools can display live data from the vehicle’s sensors and modules. This data can be used to identify problems that may not be apparent from the trouble codes alone.
For example, if you’re experiencing a rough idle, you can use a diagnostic tool to monitor the engine speed and oxygen sensor readings. This data can help you determine if the problem is caused by a faulty sensor or a vacuum leak.
Active Tests
Advanced diagnostic tools can perform active tests, such as turning on and off solenoids and sensors. This can help you identify problems that may not be apparent from the trouble codes or live data.
For example, if you’re experiencing a transmission problem, you can use a diagnostic tool to activate the solenoids that control the transmission. This can help you determine if the problem is caused by a faulty solenoid or a wiring issue.
Reporting
Advanced diagnostic tools can generate reports that can be used for troubleshooting and repairs. These reports typically include the trouble codes, live data, and active test results.
The reports can be helpful for sharing with a mechanic or for keeping track of the repairs you’ve performed on your vehicle.
| Feature | Basic Code Reader | Advanced Diagnostic Tool |
|---|---|---|
| Code Reading | Yes | Yes |
| Live Data Display | No | Yes |
| Active Tests | No | Yes |
| Reporting | No | Yes |
Troubleshooting Scanner Issues
Check the Scanner’s Connection
Make sure the scanner is properly connected to your vehicle. Inspect the OBD2 port on your car and the cable connecting the scanner. Ensure they are securely connected and free of any damage.
Power Issues
Verify that the scanner is receiving power. Check the battery or power source of your scanner and ensure it is adequately charged or plugged into a reliable outlet.
Software Compatibility
Confirm that the scanner’s software is compatible with your vehicle. Consult the scanner’s user manual or the vehicle’s manufacturer to verify compatibility.
Scanner Malfunction
If the scanner is not functioning as expected, try resetting it. This can be done by unplugging the scanner, waiting a few seconds, and plugging it back in.
OBD2 Port Issues
The OBD2 port on your vehicle may be faulty or damaged. Check the port for any loose connections, corrosion, or debris that could interfere with the scanner’s connection.
Vehicle Faults
If the scanner is unable to establish a connection with the vehicle’s ECU, there may be an underlying issue with the vehicle’s electrical system or computer. Consult a qualified mechanic to diagnose the cause.
Software Updates
Keep the scanner’s software up-to-date. Regular updates can improve the scanner’s performance and resolve any compatibility issues.
Compatibility with Specific Vehicle Models
Some scanners may not be compatible with all vehicle models. Refer to the scanner’s specifications or check with the manufacturer to confirm compatibility with your specific vehicle.
Scanner Warranty
If the scanner is within its warranty period, contact the manufacturer for assistance or a replacement. They may be able to resolve the issue or provide a replacement device.
| Possible Cause | Solution |
|---|---|
| Loose connection | Ensure the cable is securely connected to the OBD2 port and the scanner. |
| Battery issues | Charge the scanner’s battery or replace it if necessary. |
| Software incompatibility | Update the scanner’s software or consult the manufacturer for compatibility information. |
| Scanner malfunction | Try resetting the scanner by unplugging and plugging it back in. |
| OBD2 port issues | Inspect the port for loose connections, corrosion, or debris. Clean or repair the port if necessary. |
Safety Precautions
1. Park your vehicle in a safe location: Always park your vehicle on a level surface, with the parking brake engaged. This will help prevent the vehicle from rolling while you are working on it.
2. Wear appropriate safety gear: Wear safety glasses and gloves to protect yourself from any potential hazards. Safety glasses will protect your eyes from any debris that may be kicked up while you are working, and gloves will protect your hands from any hot or sharp surfaces.
3. Disconnect the negative battery terminal: This will prevent any electrical shocks while you are working on the vehicle. To disconnect the negative battery terminal, use a wrench to loosen the nut that secures the terminal to the battery. Once the nut is loose, carefully lift the terminal off of the battery post.
4. Locate the diagnostic connector: The diagnostic connector is usually located under the dashboard, near the steering wheel. It is a small, rectangular connector with 16 pins. Once you have located the diagnostic connector, plug the scanner into the connector.
5. Turn on the ignition: Turn the ignition key to the “ON” position, but do not start the engine. The scanner will now power up and begin communicating with the vehicle’s computer.
6. Select the “Read Codes” option: On the scanner’s menu, select the “Read Codes” option. The scanner will now read the trouble codes from the vehicle’s computer.
7. Clear the trouble codes: Once the scanner has read the trouble codes, select the “Clear Codes” option. The scanner will now clear the trouble codes from the vehicle’s computer.
8. Start the engine: Start the engine and let it idle for a few minutes. The check engine light should now be turned off.
9. Reconnect the negative battery terminal: Reconnect the negative battery terminal to the battery post. Tighten the nut that secures the terminal to the battery post.
10. Verify that the check engine light is off: Start the engine and let it idle for a few minutes. The check engine light should now be turned off. If the check engine light is still on, there may be a more serious problem with the vehicle. In this case, you should take the vehicle to a qualified mechanic for further diagnosis.
How To Clear Check Engine Light With Scanner
A check engine light is a warning light that illuminates on your vehicle’s dashboard when the engine control module (ECM) detects a problem. The ECM monitors various sensors and systems in your vehicle to ensure that they are operating properly. When a problem is detected, the ECM will store a trouble code in its memory and illuminate the check engine light.
There are many different reasons why a check engine light can come on, ranging from minor issues to more serious problems. Some common reasons include:
- Loose or faulty gas cap
- Faulty oxygen sensor
- Spark plug or ignition coil problems
- Catalytic converter problems
- Transmission problems
If your check engine light is on, it is important to have it diagnosed by a qualified mechanic as soon as possible. Driving with a check engine light on can lead to further damage to your vehicle and may also result in failing an emissions test.
One way to clear a check engine light is to use a scanner. A scanner is a diagnostic tool that can be used to read the trouble codes stored in the ECM. Once the trouble codes have been read, you can then use the scanner to clear the codes and turn off the check engine light.
Here are the steps on how to clear a check engine light with a scanner:
1. Connect the scanner to your vehicle’s OBD-II port.
The OBD-II port is usually located under the dashboard on the driver’s side. Once the scanner is connected, turn on the ignition but do not start the engine.
2. Turn on the scanner and select the “Read Codes” option.
The scanner will then read the trouble codes stored in the ECM and display them on the screen.
3. Once the trouble codes have been read, select the “Clear Codes” option.
The scanner will then clear the trouble codes from the ECM and turn off the check engine light.
4. Start the engine and verify that the check engine light is off.
If the check engine light is still on, there may be a more serious problem that needs to be addressed by a qualified mechanic.
People Also Ask About How To Clear Check Engine Light With Scanner
How much does it cost to clear a check engine light?
The cost to clear a check engine light will vary depending on the type of scanner used and the labor rate of the mechanic. However, the average cost is between $50 and $100.
Can I clear a check engine light myself?
Yes, you can clear a check engine light yourself using a scanner. However, it is important to note that this will only clear the light and not fix the underlying problem. If the check engine light comes back on, it is important to have your vehicle diagnosed by a qualified mechanic.
How long does it take to clear a check engine light?
It usually takes less than 5 minutes to clear a check engine light with a scanner.
