Qualcomm Diagnostic Mode or DIAG Mode is useful for changing the IMEI or repair baseband on your phone using QPST, WriteDualIMEI, and other tools. If you are facing 'cannot find DIAG COM Port' or similar error, then follow the steps listed in this tutorial to enable Qualcomm Diagnostic Mode or activate DIAG Mode.

Synaptics PS/2 Port Pointing Device driver download and installation. Download this Synaptics Input Devices device driver, then follow the procedure below. If you need help, let us know. Get fast auto repair information from the ShopKey Pro Repair Information System from Snap-on Diagnostics. NEXIQ First-Linkā„¢ is an application that provides important features to the drivers and service technicians of commercial vehicles and equipment. Download SAMSUNG Android USB Diagnostic Serial Port (WDM) Driver 5.28.0.2700 (Other Drivers & Tools). On this computer, B1, which is a new HP dv7 7212nr laptop I have had numerous problems. Today I came across the advanced tools and system diagnostics and performed the diagnostics. There were many.

Table of Contents

What is DIAG Mode?

Qualcomm DIAG Mode is a special diagnostic mode available on Qualcomm Snapdragon processor powered smartphones. When the Qualcomm Diagnostic Mode is enabled on your phone, it opens the DIAG port that helps to write or repair IMEI number using tools like QPST Tool, QFIL Tool, and other tools.

It is worth mentioning that for MediaTek (MTK) chipset powered devices, we use the Miracle Box tool to repair IMEI number, and DIAG COM Port is not required to repair IMEI on MediaTek and other processors like Spreadtrum, etc. But if you want to repair IMEI on any Qualcomm devices like Samsung, Oppo, Vivo, Xiaomi, OnePlus, Nokia, Lenovo, LG, and Motorola, then the diag port is required.

PLEASE NOTE
Windows

DIAG Port (Qualcomm HS-USB Android Diag 901D) and Qualcomm HS-USB QDLoader 9008 are separate things. Android DIAG 901D is a diag port, and HS-USB QDLoader is an EDL Mode (Emergency Download Mode).

To fix IMEI or repair baseband, it is required that your device has proper root permissions. So, make sure your device is rooted and have proper Root permissions.

How to Enable/Activate Qualcomm Diagnostic Mode on Android

There are three different methods to enable Qualcomm Diag port on your Qualcomm device. Check out all the methods below, and if one method doesn't work, then follow the other method.

[A.] Activate Qualcomm Diagnostic Mode using Diag Port Code (Dial Number)
[B.] Enable DIAG port using ADB diag Command Method
[C.] Activate Diag port using Terminal Emulator App (APK)

Enable Diag Mode using Secret Code

Some phones support activating Diag mode using the secret code. Follow the below steps to see if this method works on your device.

Snap-on Diagnostics Port Devices Driver Downloads

Open phone dialer app on your device and type #*#717717#*#*. It should enable Diag Mode, and fix cannot find DIAG COM Port error. If nothing happens, then try other methods listed below.

Enable / Activate Diag Mode from ADB

In this method, we will make use of ADB commands to enable Diag Mode. It requires that you have rooted your device and have proper root permissions.

  1. Install ADB and Fastboot drivers on your PC from here. Also, make sure to install the suitable Android USB Driver for your device model.
  2. Enable USB Debugging on your device from Settings > Developer Options. If Developer Options are missing, enable them from Settings > About Phone and tap on Build Number for about 7-10 times.
  3. Connect your device to PC and enter the below command.

    This command lists the devices connected to PC with USB Debugging enabled. If your device doesn't show up in the list, then make sure you have installed ADB, Fastboot, and USB Drivers properly.

  4. Now, type the below command and hit enter:

    This command enables Android Debug Shell. Using ADB Shell, we can perform several system actions.

  5. Now, enter the below command in CMD window and hit enter:

    This command requests superuser / Root permissions. Once the permissions are allowed, all the commands will run as the superuser.

  6. Finally, enter the below command to enable the Diag mode or Qualcomm DIAG port.
  7. Now, your device should be detected as Qualcomm HS-USB Android DIAG 901D in Device Manager.

Enable Qualcomm Diagnostic Mode using Terminal APK

  1. Make sure your device is rooted and have proper root permissions.
  2. Install Terminal Emulator app from here.
  3. Connect your device to PC.
  4. Open Terminal Emulator App and enter the below commands:
  5. Now, your device should be detected as Qualcomm HS-USB Android DIAG 901D in Device Manager.

These are the three methods using which we can enable Diag Mode and fix cannot find the DIAG COM Port problem on Android.

Have any queries? Ask them in the comment section below.

Related

This page may contain affiliate links so we earn a commission. Please read our affiliate disclosure for more info.

LG DriversModem Drivers

Supported Models

verizon model VX- Driver

LGE CDMA Composite USB Device Driver

LGE CDMA USB Modem Driver

LGE CDMA USB Modem (VCOMM) Driver

LGE CDMA USB Modem Diagnostic Serial Port Driver

Driver

LGE CDMA USB Modem Diagnostic Serial Port (VCOMM) Driver

LGE CDMA USB Serial Port Driver

Prolific USB-to-Serial Comm Port Driver

USB to Serial Port Driver

Manufacturers

Supported Operating Systems

Windows 2003, Windows XP, Windows 2000, Windows NT4, Windows ME, Windows 98SE, Windows 98, Windows 95

File Name

lg_usb_drivers.zip (710.0 KB)

Versions

1.5.0.0 (2002-04-09) via .inf
3.9.0.0 (2004-02-13) via .inf

Uploader Notes

This driver is used to connect your LG Mobile Phone to your pc with a USB datacable.

Uploaded By

dj (DG Member) on 4-Feb-2006

Most Helpful Reviews

15 of 16 people found the following review helpful:
15 Jan 2010
(41 minutes after download)

Stability:
'I tried a driver from cellphonemall.com that was supposed to be for my phone (LG VX8300), but it caused my system to lock up whenever I tried to launch any application that uses a modem. This driver, however, seems to work fine.'
12 of 13 people found the following review helpful:
1 Jul 2013
(7 minutes after download)

Stability:
'otimo site ,rapido e confiavel.'
Devices
10 of 11 people found the following review helpful:
15 Apr 2011

Snap-on Diagnostics Port Devices Driver Download

Stability:
'All drivers worked fine with my VX8100 using BitPim software interface.'
27 of 30 people found the following review helpful:
15 Mar 2006

Snap-on Diagnostics Port Devices Driver Download 64-bit

Stability:
'This seems to be the exact driver found on the Verizon CD. Works perfectly with my Verizon Cable, LG phone and BITPIM. If you lost or do nto have the CD this is the driver you want.'
23 of 26 people found the following review helpful:
9 Sep 2011
(29 minutes after download)

Stability:
'Thank you so very very much. I now can save all of my special text messages that I cherish from my kids.'

Snap-on Diagnostics Port Devices Driver Download Windows 7

Already tried it? Give your review.

See all LGE CDMA USB Modem Diagnostic Serial Port ratings and reviews

Supported Devices

Snap-on Diagnostics Port Devices Driver Download Windows 10

LGE CDMA Composite USB Device

ManufacturerLG Electronics Inc.
ClassUSB
Hardware Ids
Compatible Hardware Ids

LGE CDMA USB Modem

ManufacturerLG Electronics Inc.
ClassModem
Hardware Ids
Compatible Hardware IdsNo Compatible Hardware Ids found.
Snap-on

LGE CDMA USB Modem (VCOMM)

ManufacturerLG Electronics Inc.
ClassModem
Hardware Ids
Compatible Hardware IdsNo Compatible Hardware Ids found.

LGE CDMA USB Modem Diagnostic Serial Port

ManufacturerLG Electronics Inc.
ClassUSB
Hardware Ids
Compatible Hardware IdsNo Compatible Hardware Ids found.

LGE CDMA USB Modem Diagnostic Serial Port (VCOMM)

ManufacturerLG Electronics Inc.
ClassPorts
Hardware Ids
Compatible Hardware IdsNo Compatible Hardware Ids found.

LGE CDMA USB Serial Port

ManufacturerLG Electronics Inc.
ClassPorts
Hardware Ids
Compatible Hardware Ids

Prolific USB-to-Serial Comm Port

ManufacturerProlific
ClassUSB
Hardware Ids
Compatible Hardware Ids

USB to Serial Port

ManufacturerProlific
ClassPorts
Hardware Ids
Compatible Hardware Ids

Driver Contents File List

The following files are found inside the driver download file.

NameSizeDate
Setup.exe379.4 KB14 Apr 2004
Win2K/LGUSBBUS.INF5.8 KB7 Apr 2004
Win2K/LGUSBBUS.SYS19.9 KB7 Apr 2004
Win2K/LGUsbDiag.sys36.4 KB7 Apr 2004
Win2K/LGUsbModem.sys38.9 KB7 Apr 2004
Win2K/lgusbdiag.inf3.4 KB7 Apr 2004
Win2K/lgusbmodem.inf45.6 KB7 Apr 2004
Win2K/pl2303.cat7.1 KB30 Apr 2002
Win2K/ser2pl.inf1.9 KB9 Apr 2002
Win2K/ser2pl.sys39.6 KB9 Apr 2002
Win98/CCPORT.SYS41.5 KB7 Apr 2004
Win98/LGUSBBUS.INF5.8 KB7 Apr 2004
Win98/LGUSBBUS.SYS19.9 KB7 Apr 2004
Win98/SER9PL.sys27.3 KB7 Jan 2002
Win98/SERSPL.INF2.3 KB23 May 2001
Win98/SERSPL.VXD26.7 KB7 Jan 2002
Win98/SERWPL.INF2.5 KB29 Aug 2002
Win98/VCOMM.VXD33.1 KB30 Jan 2004
Win98/Wdmmdmld.vxd8.8 KB4 Feb 2004
Win98/lgbus9x.sys22.3 KB7 Apr 2004
Win98/lgsimdmv.inf51.9 KB7 Apr 2004
Win98/lgsisdmv.inf9.3 KB7 Apr 2004
Win98/lgusbmdm.inf3.3 KB7 Apr 2004
Win98/lgusbmdm.sys54.6 KB7 Apr 2004
Win98/lgusbsdm.inf3.4 KB7 Apr 2004
Win98/lgusbsdm.sys51.7 KB7 Apr 2004
Win98/ser2pl.sys39.6 KB9 Apr 2002
WinME/LGUSBBUS.INF5.8 KB7 Apr 2004
WinME/LGUSBBUS.SYS19.9 KB7 Apr 2004
WinME/SER9PL.sys27.3 KB7 Jan 2002
WinME/SERSPL.INF2.3 KB23 May 2001
WinME/SERSPL.VXD26.7 KB7 Jan 2002
WinME/SERWPL.INF2.5 KB29 Aug 2002
WinME/lgbus9x.sys22.3 KB7 Apr 2004
WinME/lgsimdmv.inf51.9 KB7 Apr 2004
WinME/lgsisdmv.inf9.3 KB7 Apr 2004
WinME/lgusbmdm.inf3.1 KB7 Apr 2004
WinME/lgusbmdm.sys54.6 KB7 Apr 2004
WinME/lgusbsdm.inf3.4 KB7 Apr 2004
WinME/lgusbsdm.sys51.7 KB7 Apr 2004
WinME/ser2pl.sys39.6 KB9 Apr 2002