Accessing Diagnostic Mode and COM Ports For Motorola Phones

This guide is useful for QCN extracting, IMEI repairing and other phone operations that require a COM port or diagnostic mode. Apps like DFS Studio, QFIL, QPST and Motorola RSD Lite require this in order to communicate with your Android device.

I think it’s safe to say that if you are in need of this guide, you’re already familiar with adb, fastboot, device drivers and other Android specific stuff. So we won’t over-explain all that. You will need to have the Motorola mobile drivers installed for this guide to work. If you are not familiar, then you should maybe get acquainted with the basics first and/or get some help. Here we go.

1: Boot the phone into bootloader mode (fastboot). There’s more than one way to accomplish this. This is usually done by powering the phone off. Afterwards, hold the volume down button and the power button until the phone powers on and the fastboot screen appears. It should look something like this:

2: Use the volume down button to change the menu option to “BP TOOLS” and press power to select it.

3: The phone will reboot in the normal fashion but it will be in Diag mode. Now we gotta get Windows to assign a COM port.

1: In Windows, open the Device Manager. If you don’t know how to do this you’re fired.

2: In the Device Manager, expand the “Other devices” section. You may see your device listed multiple times. If you don’t see your device listed, DIAG mode is not active and/or your drivers are not installed properly.

3: Right-click one of your devices listed and select “Update Driver”.

4: When asked “how do you want to search for drivers”, select “Browse my computer for driver software”.

5: On the next screen, select “Let me pick from a list of available drivers on my computer”.

6: At the “Select your device’s type from the list below” window, find and select “Ports (COM and LPT)” then press Next.

7: At the “Select the driver you want to install for this hardware” window, find and select Motorola in the Manufacturer pane on the left and “Motorola USB BP Diagnostic Port” in the Model pane on the right. When done press “Next”. (If you have a Qualcomm based device and have the Qualcomm drivers installed, you can also select “Qualcomm Incorporated” and choose one of the “Qualcomm HS-USB Android Diag” drivers in this step).

8: Confirm that you want to install anyway by pressing YES despite windows warning you about potential problems.

9: The drivers should install and you will be presented with a success window when done. Hit Close.

10: Now in Device Manager you should see your Motorola (or Qualcomm) device with a dedicated COM port number under the “Ports (COM and LPT)” section.

And that’s the biz!

If you had more than one device listed in step 2, you may need to repeat these steps for the remaining device listings to find out which one will give you direct access to the phone. If the first one you choose does not work. Repeat the steps on each listing until you find the working one.

To exit DIAG mode restart your phone normally.

Peace and Blessings! 🙂