OBD2 Scanner Not Connecting to Car – What Causes It and How to Fix?
Quote from CarGuyBrad on June 9, 2025, 10:09 amHey guys,
I recently bought an OBD2 scanner to diagnose my car, but it’s not connecting to the vehicle.
The scanner powers on, but it keeps saying “no communication.” I’ve tried on both my Toyota Corolla and my friend’s Honda Civic, but same issue. Could this be a problem with my car or the scanner itself?
Any help would be appreciated!
Hey guys,
I recently bought an OBD2 scanner to diagnose my car, but it’s not connecting to the vehicle.
The scanner powers on, but it keeps saying “no communication.” I’ve tried on both my Toyota Corolla and my friend’s Honda Civic, but same issue. Could this be a problem with my car or the scanner itself?
Any help would be appreciated!
Quote from Kevin Nicholas on June 9, 2025, 11:45 amHi there! This is a common issue faced by many users when their OBD2 scanner is not connecting to the car's ECU. Let me break down the possible causes and solutions:
🔍 Causes:
- Blown OBD fuse:
Most cars have a dedicated fuse for the OBD2 port. If it’s blown, your scanner won’t communicate with the car. Check the fuse box (usually 15A labeled “OBD” or “CIG”).- Incompatible scanner protocol:
Some older vehicles or cheaper scanners may not support all OBD2 protocols like CAN, ISO 9141-2, or KWP2000. Make sure your scanner supports your vehicle’s protocol.- Damaged OBD2 port or pins:
Inspect the connector for any bent or broken pins.- Ignition not in the right position:
Ensure your ignition key is in the ON position (but engine not necessarily running) before plugging in.- Faulty scanner or cable:
Try using the scanner on another working car. If it still doesn’t work, the scanner might be faulty.🛠️ Fixes:
- Check and replace the OBD fuse if necessary.
- Clean the OBD2 port using compressed air.
- Try a different scanner that supports your car’s protocol.
- Update scanner firmware if available.
- Make sure you’re using a reliable scanner brand like Autel, Innova, or BlueDriver.
Let us know which scanner model you’re using and the year/make/model of your vehicle, and we can give more targeted advice. 🚗💡
Hi there! This is a common issue faced by many users when their OBD2 scanner is not connecting to the car's ECU. Let me break down the possible causes and solutions:
🔍 Causes:
- Blown OBD fuse:
Most cars have a dedicated fuse for the OBD2 port. If it’s blown, your scanner won’t communicate with the car. Check the fuse box (usually 15A labeled “OBD” or “CIG”). - Incompatible scanner protocol:
Some older vehicles or cheaper scanners may not support all OBD2 protocols like CAN, ISO 9141-2, or KWP2000. Make sure your scanner supports your vehicle’s protocol. - Damaged OBD2 port or pins:
Inspect the connector for any bent or broken pins. - Ignition not in the right position:
Ensure your ignition key is in the ON position (but engine not necessarily running) before plugging in. - Faulty scanner or cable:
Try using the scanner on another working car. If it still doesn’t work, the scanner might be faulty.
🛠️ Fixes:
- Check and replace the OBD fuse if necessary.
- Clean the OBD2 port using compressed air.
- Try a different scanner that supports your car’s protocol.
- Update scanner firmware if available.
- Make sure you’re using a reliable scanner brand like Autel, Innova, or BlueDriver.
Let us know which scanner model you’re using and the year/make/model of your vehicle, and we can give more targeted advice. 🚗💡
Quote from AutoFixerMike on June 9, 2025, 2:10 pmHad the exact same issue with my 2010 Toyota Camry. Turned out the OBD2 fuse was blown. Replaced it with a 15A fuse and my Innova scanner started working perfectly. Definitely check that first — it’s a quick fix!
Had the exact same issue with my 2010 Toyota Camry. Turned out the OBD2 fuse was blown. Replaced it with a 15A fuse and my Innova scanner started working perfectly. Definitely check that first — it’s a quick fix!
Quote from Deleted user on June 10, 2025, 8:06 amSometimes the scanner won’t connect if your battery voltage is low. I had a weak battery and my BlueDriver wouldn’t pair over Bluetooth. After charging the battery, everything worked fine. Just something to consider!
Sometimes the scanner won’t connect if your battery voltage is low. I had a weak battery and my BlueDriver wouldn’t pair over Bluetooth. After charging the battery, everything worked fine. Just something to consider!
Quote from DIYDan on June 10, 2025, 2:03 pmMake sure the car key is turned to the ON position. So many people forget that! Without it, most scanners won’t communicate with the ECU at all. Especially on older models.
Make sure the car key is turned to the ON position. So many people forget that! Without it, most scanners won’t communicate with the ECU at all. Especially on older models.
Quote from WrenchWizard on June 16, 2025, 12:31 pmI had this happen with my 2006 Civic. My cheap eBay scanner wasn’t compatible with the ISO 9141-2 protocol. Bought a better scanner (Foxwell NT301) and now no problems.
I had this happen with my 2006 Civic. My cheap eBay scanner wasn’t compatible with the ISO 9141-2 protocol. Bought a better scanner (Foxwell NT301) and now no problems.