Method A — Engineering code
Dial:
*#*#83781#*#* or *#*#3646633#*#*
Go to Log and Debug → USB Port Settings → Enable DIAG, disable others if needed.
Method B — Via ADB
adb shell
su
setprop persist.sys.usb.config diag,adb
Method C — Hardware key combo (varies by model): sprd u25 diag driver work
Check Device Manager — a new unknown device appears when done correctly.
Most Spreadtrum Diag drivers are unsigned, so Windows blocks them by default. Method A — Engineering code Dial: *#*#83781#*#* or
The SPRD U25 Diag Driver is a proprietary software driver that enables diagnostic communication between a host PC and a device powered by a Unisoc U25 chipset (commonly found in IoT modules, feature phones, or low-end smartphones). It uses a proprietary diag protocol over interfaces like USB or UART to access internal chipset logs, memory dumps, modem states, and other debug information.
Use a terminal program (Putty, RealTerm, or HyperTerminal) on the COM port (e.g., COM5, 115200 baud, 8N1). Method C — Hardware key combo (varies by model):
Send AT+CGMI or AT+GSN — should return manufacturer and IMEI if diag port works.
Or use SPD SN Writer or ResearchDownload — select the correct COM port in tool settings.
Method A — Engineering code
Dial:
*#*#83781#*#* or *#*#3646633#*#*
Go to Log and Debug → USB Port Settings → Enable DIAG, disable others if needed.
Method B — Via ADB
adb shell
su
setprop persist.sys.usb.config diag,adb
Method C — Hardware key combo (varies by model):
Check Device Manager — a new unknown device appears when done correctly.
Most Spreadtrum Diag drivers are unsigned, so Windows blocks them by default.
The SPRD U25 Diag Driver is a proprietary software driver that enables diagnostic communication between a host PC and a device powered by a Unisoc U25 chipset (commonly found in IoT modules, feature phones, or low-end smartphones). It uses a proprietary diag protocol over interfaces like USB or UART to access internal chipset logs, memory dumps, modem states, and other debug information.
Use a terminal program (Putty, RealTerm, or HyperTerminal) on the COM port (e.g., COM5, 115200 baud, 8N1).
Send AT+CGMI or AT+GSN — should return manufacturer and IMEI if diag port works.
Or use SPD SN Writer or ResearchDownload — select the correct COM port in tool settings.
