How To Use Secret Codes On Oppo A9 2020 Upd 【2026 Release】

Since ColorOS 11+ blocks many codes:

The OPPO A9 2020 is a powerful mid-range smartphone known for its massive battery, quad-camera setup, and smooth ColorOS interface. However, like most Android devices, it hides a treasure trove of diagnostic tools, test menus, and engineering screens behind a series of secret codes (also known as USSD codes or MMI codes).

If you have searched for "how to use secret codes on oppo a9 2020 upd", you are likely looking for the latest, working codes to test your hardware, access advanced settings, or recover information. This updated guide for 2025-2026 provides a complete, step-by-step walkthrough.

⚠️ Warning: Secret codes give access to system-level tests. Do not change values in "Engineering Mode" or "Device Test" unless you know exactly what you are doing. Incorrect settings can affect your phone's performance.

The process is simple and works exactly like making a phone call:

Code: *#*#232338#*#* Shows your Wi-Fi MAC address without going into Settings → About Phone.

Code: *#*#232337#*#* Shows your Bluetooth device address.

Your keyword includes "upd" — likely seeking update-related secret codes. Here they are:

Would you like a version formatted as a video script, Instagram carousel, or blog post? how to use secret codes on oppo a9 2020 upd

To use secret codes on your OPPO A9 2020, open the Phone (Dialer) app and type the specific sequence of numbers and symbols. Most codes execute automatically once the final character (usually #) is entered, without needing to press the call button.  Essential Secret Codes 

IMEI Information (*#06#): Instantly displays your device's unique IMEI number, which is vital for tracking or reporting a lost phone.

Engineering/Diagnostic Mode (*#899# or *#800#): Opens a hidden menu to test hardware components like the screen, GPS, and Bluetooth.

Software Information (*#6776#): Provides detailed technical specs, including Android version, kernel version, and ColorOS build.

Hardware Revision (*#888#): Shows the PCB (mainboard) serial number and hardware version.

Maximum SAR Level (*#07#): Displays the Specific Absorption Rate (radiation level) of your device.  Service and Testing Codes 

Calendar Info (*#*#225#*#*): Accesses a hidden page showing saved calendar events and related data.

FCM Diagnostics (*#*#426#*#*): View connection status and events related to Firebase Cloud Messaging. Since ColorOS 11+ blocks many codes:

GPS Test Mode (*#802#): Enters an automated TTFF (Time to First Fix) test for GPS. 

Watch this step-by-step guide to see these codes in action and learn how to navigate the hidden service menus safely: 02:06

Used to report logs for issues like lag, GPS problems, or battery drain. Hardware Revision The OPPO A9 2020 is a powerful mid-range

Displays the mainboard (PCB) serial number and hardware version.

Shows the Specific Absorption Rate for radiation safety standards. *#*#4636#*#* Usage Statistics

Provides advanced information about the battery, Wi-Fi status, and app usage. *#*#225#*#* Calendar Info

Displays events saved in your calendar and upcoming holidays. Advanced Hidden Menus

Beyond dialing codes, you can unlock additional capabilities through the system settings: Codes for OPPO A9 2020 - HardReset.info

Disclaimer: These codes are intended for advanced users and developers. Some codes can reset your device, delete data, or change critical system settings. Proceed at your own risk. It is highly recommended to back up your data before experimenting with unknown codes.

Code: *#*#682#*#* This forces the phone to ping the OPPO update server immediately. It’s more aggressive than tapping "Check for Updates" in Settings.