TCL 40 R 5G sometimes drops to 4G to save battery. Use Engineering Mode → Telephony → Band Select → Choose NR5G only (advanced).
These are your most powerful diagnostic tools.
Bookmark this guide. Your TCL 40 R 5G has a hidden powerhouse of diagnostics—now you know exactly how to use it.
A: Some TCL firmware hides Phone Info. Use “Force LTE Only” (4G Switcher) app from Play Store instead.
Checks the Firebase Cloud Messaging status and server connection events. *#*#225#*#* Calendar Info
| Code | Function | |------|-----------| | *#*#34971539#*#* | Camera firmware details (not always supported on TCL but worth trying). | | *#*#0588#*#* | Proximity sensor test – move hand over top of phone to see status change. | | *#*#0589#*#* | Light sensor test (shows ambient light readings in lux). | | *#*#1575#*#* | GPS test menu – see satellite lock count and accuracy. Great for mapping app issues. |
Dial *#*#4636#*#* → “Phone Information” → Set preferred network type to “LTE/NR” (5G) instead of global. Many users report better signal locking.
TCL 40 R 5G sometimes drops to 4G to save battery. Use Engineering Mode → Telephony → Band Select → Choose NR5G only (advanced).
These are your most powerful diagnostic tools. How to Use Secret Codes on TCL 40 R 5G
Bookmark this guide. Your TCL 40 R 5G has a hidden powerhouse of diagnostics—now you know exactly how to use it. TCL 40 R 5G sometimes drops to 4G to save battery
A: Some TCL firmware hides Phone Info. Use “Force LTE Only” (4G Switcher) app from Play Store instead. Bookmark this guide
Checks the Firebase Cloud Messaging status and server connection events. *#*#225#*#* Calendar Info
| Code | Function | |------|-----------| | *#*#34971539#*#* | Camera firmware details (not always supported on TCL but worth trying). | | *#*#0588#*#* | Proximity sensor test – move hand over top of phone to see status change. | | *#*#0589#*#* | Light sensor test (shows ambient light readings in lux). | | *#*#1575#*#* | GPS test menu – see satellite lock count and accuracy. Great for mapping app issues. |
Dial *#*#4636#*#* → “Phone Information” → Set preferred network type to “LTE/NR” (5G) instead of global. Many users report better signal locking.