The phone will process the code immediately. You do not need to press the call button for most codes. Essential Oppo A9 2020 Secret Codes 1. The Engineer Mode Code (Most Useful) *#899#
Monitors push notification delivery pathways and active server connection status. Specific Absorption Rate (SAR) Level
It's a powerful diagnostic tool built into your phone's firmware, primarily used by technicians to test hardware and software. You can think of it as a behind-the-scenes service menu for your device.
Shows detailed software parameters including ColorOS version, kernel, and build time. Feedback Menu how to use secret codes on oppo a9 2020 upd
: Provides deep details including Android version, kernel version, ColorOS version, and build branch.
Most codes will execute automatically as soon as the last character is entered. If they don't, tap the Essential Secret Codes for OPPO A9 2020
*#*#232338#*#* Shows your Wi-Fi MAC address without going into Settings → About Phone. The phone will process the code immediately
*#*#1029#*#* Allows you to apply a local OZIP or ZIP update file if you have downloaded the full ROM from OPPO’s support site. Do not use random files from the internet.
After a major update (e.g., ColorOS 6 to 11), OPPO may disable certain codes for security. If a code fails:
This is perhaps the most important question for anyone who has recently updated their Oppo A9 2020. As Oppo has evolved ColorOS, the company has significantly restricted access to hidden diagnostic menus. The primary reason is security: these codes grant deep system access, and leaving them open could potentially be exploited by malicious actors. As a result, many codes that worked on older ColorOS versions (like the original Android 9 Pie with ColorOS 6.1 that shipped with the Oppo A9 2020) are now disabled on newer updates. The Engineer Mode Code (Most Useful) *#899# Monitors
Here are some popular secret codes for Oppo A9 2020:
. These codes, often called USSD or MMI codes, provide access to hidden menus for hardware testing, software information, and system diagnostics. How to Enter Codes (dialer) app. Tap on the Carefully type the code (e.g.,
In most cases, the menu or information will after you type the last character. If nothing happens, press the Call button to execute the command. Essential Secret Codes List Below is a curated list of frequently used codes for the OPPO A9 2020