When you connect your OBD2 scanner to your vehicle’s OBD-II port, it’s designed to power on immediately. Typically, a beep or a light indicates that it’s receiving power and ready to communicate with your car’s computer. However, if your OBD2 scanner is not turning on, it can be frustrating, leaving you unable to diagnose potential car problems.
This guide will walk you through the common reasons why your OBD2 scanner is not turning on and provide step-by-step troubleshooting to get you back on track. We’ll cover everything from simple connection checks to examining fuses and using a multimeter.
Initial Checks: Ensuring a Solid Connection
The most frequent cause for an Obd2 Scanner Not Turning On is a poor connection. Like any electronic device, a scanner needs a stable power supply to function. Let’s start with the basics:
Direct Connection to the OBD-II Port
If you are plugging your OBD2 scanner directly into the OBD-II port, the first step is to ensure it’s firmly seated. Sometimes, it might seem plugged in, but a slight misalignment can prevent proper contact.
Steps to check direct connection:
- Unplug the OBD2 scanner from the OBD-II port.
- Inspect the connector for any damage or debris.
- Firmly plug the scanner back into the OBD-II port, ensuring it is fully inserted.
- Listen for a beep or check for a power light on your scanner.
If your scanner still isn’t powering on, proceed to the next checks.
Using an OBD-II Extension Cable
Many users employ an OBD-II extension cable for easier access or to keep the scanner out of the way. While convenient, these cables introduce additional connection points that can be potential sources of power issues.
If you are using an OBD-II extension cable, troubleshoot each connection point separately.
Check the Cable Connection to the OBD-II Port
A loose or faulty connection at the vehicle’s OBD-II port end of the extension cable can prevent power from reaching the scanner.
Steps to check cable to OBD-II port connection:
- Turn off your vehicle’s engine.
- Unplug the extension cable from the vehicle’s OBD-II port.
- Wait for 5 minutes. This brief wait can sometimes reset the OBD-II port if there was a minor electrical glitch.
- Plug the extension cable firmly back into the OBD-II port.
- Connect your OBD2 scanner to the other end of the extension cable and check for power.
If the scanner now powers on (you hear a beep or see a light), the issue was likely a loose connection at the OBD-II port.
Check the Cable Connection to the Scanner
If the previous step didn’t resolve the issue, the problem might be at the connection point between the extension cable and the OBD2 scanner itself.
Steps to check cable to scanner connection:
- Ensure the engine is off.
- Unplug the OBD2 scanner from the extension cable.
- Wait 5 minutes.
- Reconnect the OBD2 scanner firmly to the extension cable.
- Check if the scanner now powers on.
If you hear a beep or see a power light, the connection between the cable and the scanner was likely the culprit.
Test the OBD2 Scanner Directly
To isolate whether the issue lies with the scanner itself or the extension cable, test the scanner by plugging it directly into the OBD-II port, bypassing the extension cable entirely.
Steps to test the scanner directly:
- Disconnect the extension cable from both the OBD-II port and the scanner.
- Plug the OBD2 scanner directly into the vehicle’s OBD-II port.
- Check if the scanner powers on.
If the scanner powers on when directly connected, but not with the extension cable, the problem is likely with the OBD-II extension cable or its fuse (if it has one).
Examining the Extension Cable’s Fuse
Some OBD-II extension cables come with an inline fuse to protect the scanner and your vehicle’s electrical system. A blown fuse in the extension cable will prevent power from reaching the OBD2 scanner.
Steps to check the cable’s fuse:
- Locate the fuse holder on the extension cable. It’s usually a small, rectangular component.
- Open the fuse holder cap to access the fuse.
- Remove the fuse.
- Inspect the fuse. A blown fuse will typically have a broken wire inside or a darkened appearance.
- Test the fuse with a multimeter for continuity or replace it with a new fuse of the same rating (usually 3A mini-blade fuses, available at auto parts stores).
- If replacing, insert the new fuse into the fuse holder and close the cap.
- Reconnect the extension cable and the OBD2 scanner and check for power.
If replacing the fuse resolves the issue, the original fuse was likely blown. If not, the problem might be with the cable itself or further upstream in your vehicle’s OBD-II port.
Checking the OBD-II Port and Vehicle Fuses
If you’ve ruled out connection issues and the extension cable (or if you’re not using one), the problem might be with the vehicle’s OBD-II port itself or the fuses that power it.
Testing the OBD-II Port for Power
The OBD-II port should receive power from your vehicle’s electrical system. You can use a digital multimeter to check if the port is receiving power.
Steps to test OBD-II port power:
- Set your digital multimeter to measure DC voltage.
- Locate pins 16, 4, and 5 on your vehicle’s OBD-II port. Pin 16 is the power pin, pin 4 is chassis ground, and pin 5 is signal ground. (Refer to an OBD-II port pinout diagram if needed).
- Connect the red lead (positive) of your multimeter to pin 16.
- Connect the black lead (negative) of your multimeter to pin 4 or 5.
- Check the voltage reading on the multimeter.
Ideally, you should see approximately 12 volts, indicating that the OBD-II port is receiving power. If the multimeter reads 0 volts, the OBD-II port is not getting power, and you need to check your vehicle’s fuses.
Checking Vehicle Fuses Related to the OBD-II Port
The OBD-II port is typically powered through a fuse in your vehicle’s fuse box. Often, this fuse is shared with the auxiliary power outlets (cigarette lighter sockets), and might still be labeled as “cigarette” or “auxiliary” in your fuse box diagram.
Steps to check vehicle fuses:
- Locate your vehicle’s fuse box. Consult your owner’s manual for its location and fuse box diagram.
- Identify the fuse associated with the auxiliary power outlets or OBD-II port (refer to the fuse box diagram).
- Remove the fuse.
- Inspect the fuse for any signs of being blown (broken wire, darkened appearance).
- Test the fuse with a multimeter or replace it with a new fuse of the same rating.
- If replacing, insert the new fuse into the fuse box.
- Test your OBD2 scanner again.
If replacing a blown fuse restores power to the OBD-II port and your scanner now turns on, the blown fuse was the issue.
Checking car fuses with a multimeter
Alt text: A close-up of a person using a digital multimeter to test a car fuse, demonstrating how to check for continuity and identify a blown fuse in a vehicle’s electrical system.
If the OBD-II port and related fuses are working correctly, and your OBD2 scanner is still not turning on, the issue might be with the scanner itself, requiring repair or replacement.
Still Having Trouble? Contact Support
If you have diligently followed all these troubleshooting steps and your OBD2 scanner is still not turning on, it’s time to seek professional assistance.
For further support, contact our support team. Our experts can provide advanced troubleshooting and, if necessary, arrange for a technician to assist you.
To expedite the support process, please have the following information ready when you contact us:
- Vehicle year, make, and model
- Date and time of the last successful OBD2 scanner connection (if applicable)
- Your contact information
- Location where a technician can be sent if needed
By providing this information, we can efficiently diagnose the issue and get your OBD2 scanner working again.
Need More Help?
Contact Support
Related Articles:
- Why is my vehicle not reporting?
- Discover plug and play (OBD-II) vehicle tracker compatibility
- How to install plug and play (OBD-II) vehicle trackers
