Step 1: Check for the Serial Number
Turn off your car's ignition.
Find the radio's serial number. This is usually printed on a sticker at the top or bottom of your radio's faceplate.
Step 2: Calculate the Unlock Code
Using a VIN decoder or online calculator, enter the serial number to generate an unlock code.
Double-check the code to ensure that it's accurate.
Step 3: Prepare Your Radio
Turn the ignition to the first position (accessory mode) without starting the engine.
Press and hold the "1" or "6" preset button on your car radio. Keep holding the button even when the radio display changes.
While still holding the button, turn the ignition to the second position (engine on) without starting the engine.
Continue to hold the preset button until the display changes and the code input mode appears.
Step 4: Enter the Unlock Code
Use the radio's buttons to input the unlock code you calculated earlier.
Press the preset button to confirm each digit.
Check that you've entered the correct code.
Step 5: Complete the Unlock Process
Once the unlock code is entered, the radio display should change and the error 4 message should disappear.
Turn off and then turn on the ignition to check that the radio is unlocked.
Remember, the exact process may vary slightly depending on your Peugeot car model and year. If the above steps don't work, you may need to consult your vehicle's manual or a professional car audio installer for assistance.
