How to Install ELM327 USB Cable on Windows and OBD2 Software
Posted by Alex (Im) E. on 13 October 2011 02:18 PM
elm327 scan tool
Typical ELM327 USB Car Diagnostics Scanner
This article will guide you how to install ELM327 USB cable/scanner on your Windows computer. It will then work with any OBD2 software and your car.

(If ELM327 USB isn't setup properly as per instructions below — then OBD software will not even detect the cable — let alone connect to the vehicle.)

Related Resources:


Windows XP, 7, 8, 10, 11 Install Instructions:

Connect the ELM327 USB to your laptop. Let Windows automatically install the drivers.

To check that drivers are installed CORRECTLY...

Search for "Device Manager" » Expand "Ports (COM & LPT)".

Ensure there is NO yellow exlamation marks (that looks like this device error in windows) next to devices such as: USB-Serial CH340 | FT232R USB UART Prolific | USB-to-Serial | USB Serial Port | USB2.0-Serial | Silicon Labs CP210x USB to UART Bridge

a If no yellow mark, then congratulations! You're ready to begin scanning your car(s). Click here on how to connect to your car in the next 5 minutes...

a If any one of above devices has a yellow mark (device error in windows), then: Install below driver pack 1. Restart PC, check for mark. If still mark, then install driver pack 2. Repeat.


DRIVER PACK 1 (click to download)

   Steps to install Driver Pack 1:

  • If you have 64-bit Windows, double-click on: CP210xVCPInstaller_x64
  • If you have 32-bit Windows, double-click on: CP210xVCPInstaller_x86




DRIVER PACK 5   Most Important!

   Steps to install Driver Pack 5:

  1. Please FIRST move the unextracted folder to your Desktop, else below #2 step won't show "Install" option.

  2. Right-click on "ser2pl" (icon has a little gear pic in it) and choose "Install", as per below pic:
    windows 8 prolific drivers

  3. Connect ELM327 cable to your laptop. Then...

    Search for "Device Manager". Open it » Ports (COM & LPT)

    You will likely see a yellow mark next to "Prolific", like this:
    windows 8 prolific

    Right-click on it » Update Driver Software

  4. Click "Browse my computer for driver software".

  5. Select "Let me pick from a list of device drivers on my computer".

  6. UNcheck "Show compatible hardware". a

  7. Select: Prolific driver version
    windows 8 prolific

  8. Install. That's it! The yellow triangle next to "Prolific..." should be gone.



  1. Download and unextract. 
  2. Double-click on "InstallUSB" to install
  3. Connect cable to laptop. Yellow mark should now be gone. Success!

    If yellow mark is STILL not gone after doing 1-6 above, then do this:

    a) While cable is plugged in, right-click on device with the yellow mark.
    b) Click on: Update Driver Software
    c) Choose: Browser my computer for driver software
    d) Browse to and select folder where you unextracted Driver Pack 6. Make sure "Include subfolders" is ticked ON.
    e) Click on: Next
    f) If you get RED warning, choose: Install this driver software anyway
    g) After it installs successfully, another yellow mark may appear under "Other Device". Eg: yellow-mark-other-devices-elm327
    h) If g above is true, then do steps a-f for "Unknown Device". It may also show as "COMx".

a Even DRIVER PACK 6 didn't help? Then likely it's a "Code 10 error" next to "Prolific USB-to-Serial" device. Click here to fix that.

a Even "Code 10 error" fix didn't help and yellow mark (device error in windows) is STILL not gone? Go to Troubleshooting below.




How To Scan / Diagnose Any Car with OBD2 Software...

Step 1: Install your OBD2 software (if you don't have it — checkout TOAD OBD software). Do NOT launch it yet.

Step 2: Connect ELM327 USB to your computer and car's OBD port (usually underneat dashboard/steering wheel).

Step 3: Place the key in the ignition and turn it forward to "ON" position. (Position where all dashboard lights are on. This is one position before engine starts.)

Step 4: Start your OBD diagnostic software. Click "Connect", and it should auto-connect to your vehicle. That's it!


TIP: If you want maximum data reported from the car — turn on the engine.

Yes, you can safely drive the vehicle while ELM327 is plugged in and application is monitoring car's data. Keep eyes on the road at all times.




Troubleshooting: Solutions for ELM327 Connection Issues...

Common Solutions:

If you're unable to connect successfully to your car, then that's because of 2 reasons:

  1. Your vehicle is not OBD2 compatible.

  2. Random issues that can be fixed with below solutions...


Here are solutions in recommended order:

  1. First check that ELM327 is physically working (not defunct). When you plug in the cable into a USB port, all the lights on ELM327 interface/device should flash. And then it'll return to 1 red light (power).

           Condition of a defunct ELM327 interface: All lights will not initially flash, and only red light will be on.

  2. Restart computer (while keeping cable connected to laptop). Try again.

  3. Plug USB into different physical port of your computer. Try again.

  4. If all above solutions fail, then we will help you (only if you are Total Car Diagnostics customer). Here's all you need to do...

    Connect ELM327 USB cable into laptop. (Don't need to plug the other end to car)

    Step 1: Go to Control Panel.

    Windows Vista/7/8/10: Control Panel » System » Device Manager
    Windows XP: Control Panel » System » "Hardware" tab » Device Manager

    Step 2: Expand "Ports (COM & LPT)" and "Other Devices".

    Step 3: Take picture of the screen (Press "Print Screen" key on the keyboard then paste into any graphics program. Or take shot with camera/phone.)

    Step 4: Contact us and attach the picture.


Free Software To Test If ELM327 is Working with Windows and Vehicle...

Step 1: Install EasyOBD. Do not launch it until Step 4 below.

Step 2: Connect ELM327 USB/Bluetooth to laptop and car.

Step 3: Turn on car ignition. (One step before engine turns on)

Step 4: Launch EasyOBD. It will automatically connect.


If first 5 lines are GREEN — then ELM327/Windows is 100% installed correctly. In this case, can get TOAD pro software.

If any of the first 5 lines are RED — then OBD2 scanner won't work on your car. Rather take it to mechanic.



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