Serial Number Location Guide for Honda Passport 2021
The first part is to find the radio's serial number.
Based on the head unit type fitted in your 2021 Passport, the S/N can be found either through the display menu or by pulling the unit out and checking the label on the radio itself.
Follow the steps below to identify your S/N quickly.
2021 Passport - Identifying Your Factory Head Unit
- 5-inch Color LCD Audio (Sport) - the smaller 5-inch non-touch colour LCD in the upper centre dash, with physical buttons and a rotary knob beneath the screen. Standard with AM/FM, Bluetooth HandsFreeLink and a 7-speaker, 215-watt audio system. The Sport trim does not get Apple CarPlay or Android Auto on its 5-inch unit and is the only 2021 Passport trim with this head-unit family.
- 8-inch Display Audio with High-Resolution Electrostatic Touch-Screen (EX-L, Touring, Elite) - the 8-inch landscape touchscreen with capacitive Home, Back and Brightness touch controls down the left edge and a volume/power knob. Apple CarPlay and Android Auto are standard (wired), along with Bluetooth, SiriusXM, HD Radio and HondaLink. Software updates wirelessly over Wi-Fi from the Settings menu.
- 8-inch Display Audio with Honda Satellite-Linked Navigation (Touring, Elite) - the same 8-inch hardware as the EX-L unit but with factory navigation baked in and turn-by-turn directions on the head unit's display. Touring and Elite trims pair this unit with a 10-speaker, 590-watt premium audio system; the EX-L keeps the 7-speaker, 215-watt setup. The Elite trim also adds wireless phone charging in the centre console.
- For code retrieval purposes - your 2021 Passport falls into one of two head-unit families: the 5-inch Audio module (Sport) or the 8-inch Display Audio module (EX-L and above, with or without navigation). Audio package and trim level change the speakers and amplifier, not the head-unit module that holds the anti-theft code.
Using Hidden Radio Menus to Find the Serial
Try the following for your 2021 Honda Passport:
The 2021 Honda Passport could have Honda's Display Audio system (8" depending on trim) or a standard non-touchscreen radio. All versions support serial number display via the 1+6 button method:
- Turn ignition to ON. Wait for the radio to power up. The screen shows "CODE" when anti-theft is active.
- Simultaneously press preset buttons 1 and 6 for about 5 seconds.
- The serial number displays in two halves (e.g.,
U3210+L0482).
Also: On 2021 Passport with the Display Audio touchscreen, check Settings → System → Device Information – the serial may be listed there instead of the button combination.
Taking Out the Radio Unit to Access the S/N on the Tag
If the serial does not appear on screen, the next step is checking the radio itself.
Many Honda radios require physical access to the ID label attached to the unit.
Usual approach:
- Start by completely shutting off the engine - pull the key out.
- Then detach the radio surround.
- Next, loosen the mounting points and move the radio forward.
- Look for a barcode label showing the serial number.
If none of these methods succeed on the 2021 Honda Passport:
- Power down the vehicle.
- Remove the center stack trim panel. The 2021 Passport's integrated dashboard uses plastic clips.
- For Display Audio models: Remove the mounting screws (Phillips-head) securing the display module.
- On base trims: Unscrew the 4 Phillips screws holding the radio unit.
- Ease the unit forward and read the serial on the label on the back or side.
Tip: The touchscreen unit is wider and more integrated than the standard radio. Be careful when extracting it.
Pulling the Head Unit on a 2021 Passport
- Safety first. Park on a flat surface, set the parking brake, switch the ignition off and take the key/fob out of reach. Disconnect the negative (-) terminal of the 12V battery and wait at least three minutes for the SRS (airbag) capacitor to discharge before touching anything in the centre stack - the passenger airbag harness runs close to the head-unit bezel.
- Tools you will want. A set of plastic trim removal tools, a 10mm socket on a short extension, and a small Phillips screwdriver. Masking tape around the bezel protects the soft-touch dashboard from scuffs.
- Release the centre trim bezel. The 2021 Passport's centre stack is a one-piece gloss-black panel surrounding the head unit and the climate controls. Insert a plastic trim tool at the lower edge and work the spring clips loose along the bottom first, then up each side. The whole panel comes forward as one piece. Tilt it toward you and disconnect the climate-control and accessory connectors at the back so the panel can be set aside.
- Unbolt the radio chassis. Four 10mm bolts hold the radio into the dashboard cradle - two at the top corners and two at the bottom corners. Remove all four. Slide the unit straight out a few centimetres, then disconnect the wiring harness, antenna lead and (on Display Audio units) the USB and HDMI ribbon connectors at the back. The head unit is now free.
- Read the serial. The serial number sticker sits on the top or side of the metal chassis - a small white label with a barcode and an alphanumeric serial. Photograph it with your phone for the radio-code request.
- Reassembly. Reverse the sequence: rear connectors first, four 10mm bolts back in, climate panel connectors reattached, trim bezel pressed back into its spring clips, then reconnect the battery negative terminal last. On power-up the radio will prompt for its anti-theft code.
- Dealer alternative. Any Honda dealer can read the radio serial directly through their HDS (Honda Diagnostic System) tool plugged into the OBD-II port - no physical removal is needed. This is the fastest and lowest-risk path on a near-new Passport.
Example: Honda Passport serial number label location
What a Valid Serial Number Looks Like
Based on which radio fitted to the 2021 Honda Passport:
U1234L5678– Standard Honda OEM formatHBM####– Used in Display Audio and navigation units913A####– Some Alpine-manufactured radios
The 2021 Passport may have: base CD radio (U/L format), Display Audio 5"/7" (HBM format), or navigation unit (HBM format). All use a 5-digit unlock code.
Important Ensure you record the serial number, not the part number (which starts with 39100, 39101, or similar Honda part coding).
2021 Passport Radio Serial Format
The 2021 Passport's 5-inch Audio (Sport) and 8-inch Display Audio (EX-L and above) head units carry the standard Honda 8-character alphanumeric serial. It contains only digits 0-9 and uppercase letters A-Z, with no spaces, dashes or special characters, and is laser-printed or sticker-printed onto the metal chassis of the unit. Older Honda single-DIN radios show this same serial in a split 'U' (upper) and 'L' (lower) format on a dealer-mode display that you concatenate into the 8-character string - whether the 2021 Passport Display Audio still supports that split dealer-mode display is not publicly confirmed for this model year, so the most reliable reference is always the chassis sticker or an HDS read at a Honda dealer.
Code Entry Instructions
After locating the radio serial and received the unlock code, the final step is entering it into your radio.
Honda OEM units display a CODE prompt when ready for input.
The process is straightforward, but button layouts and confirmation methods may vary depending on the radio version installed in your Passport.
Step-by-Step - Correct Entering Process
To enter the code on the 2021 Honda Passport:
- Ignition ON. Radio shows "CODE" or "ENTER CODE".
- Non-touchscreen models: Use preset buttons 1-5 to select each digit, then press and hold button 6 to confirm.
- Display Audio touchscreen: An on-screen keypad may appear. Enter each digit and press "Enter" or "OK".
Lockout: 3 wrong attempts trigger a 60-minute lockout. Keep ignition ON. Do not cycle the key or the timer resets.
Entering the Code on the 2021 Passport
- Touchscreen entry on the 8-inch Display Audio (EX-L / Touring / Elite). When the unit displays 'Enter Code', a numeric keypad appears on the touchscreen. Tap the five digits of your code in order, then tap Enter (or Done) on the touchscreen. The radio will resume normal operation if the code is accepted, or show the remaining attempts if it is rejected.
- Preset-button entry on the 5-inch Audio (Sport). Use the preset buttons on the front of the head unit to enter each digit. The presets work as number keys: tap the one that matches each digit of the code once, in order (a code of 52164 is preset 5, 2, 1, 6, 4). On some firmware revisions the tuning knob and a confirmation button are used instead, and the on-screen prompt will tell you which.
- Lockout protection. Honda head units typically lock out after about ten failed attempts and need a one-hour cooldown with the radio powered on before further attempts are accepted. Leave the ignition in accessory and the radio on, then retry once the lockout has cleared.
- VIN-pairing note. Some 2021 Display Audio units may revalidate against the VIN through HDS after a battery disconnection. If the correct code is rejected and the unit refuses to unlock, a Honda dealer can re-pair the head unit through their diagnostic tool.
Locked Passport Radio? Here's Exactly How to Get the Code
Vehicle radios use anti-theft codes tied to the radio unit itself rather than the vehicle model or production year.
- The generator identifies your Honda radio via serial-based verification.
- After entering the serial into the form above, the system identifies the radio family and retrieves the corresponding code.
- Use the code to unlock the radio immediately.
- This approach saves time compared to traditional methods for 2021 Honda Passport.
Why Did the Radio Lock and Ask for a Code?
Honda's Display Audio system retains the same anti-theft design as earlier radios: losing battery power triggers a code request at next startup. Applies to both the base radio and the Display Audio unit.
- Battery replacement — the usual culprit.
- Battery disconnect during repairs — any work that interrupts battery power will re-engage the lock.
- Completely dead battery — a fully discharged battery also triggers the request.
Worth knowing: a number of higher-trim Display Audio models from this era might not use a traditional code-based lock — if the radio never showed "CODE" after losing power, it could have a different anti-theft method linked to the vehicle VIN.
Understanding Unlock Issues with Your Passport
If the Display Audio screen powers on but goes straight to the home screen without any "CODE" prompt, consider these points:
- Anti-theft may not have triggered — certain battery changes don't trigger the lock if power was restored fast.
- On some Display Audio units, the code prompt shows only on the audio portion of the screen, not the navigation display — wait a moment after startup.
- Try the Settings → System → Device Information route; if the serial is visible there, the unit may still be functional without a code.
Should none of the above match, a fuse check is the next step — a failed fuse prevents the radio from powering on at all.
Code entry depends on the specific radio in the Display Audio-era Passport:
- Non-touchscreen base radio: Use preset buttons 1–5 to scroll to each digit, then press and hold button 6 to confirm — identical to older Honda platforms.
- Display Audio 5" or 7" touchscreen: An on-screen numeric keypad is shown when the code prompt is active. Enter the digits and press OK or Enter on screen.
If the touchscreen is unresponsive, attempt the physical preset buttons — some units support either input method. Make sure the screen is fully booted before starting entry.
The Display Audio platform uses the same three-try lockout as older Honda radios. To recover:
- Leave the ignition in ON or ACC — do not switch off.
- Wait out the full 60-minute period. The touchscreen might dim during this time — that's normal.
- After 60 minutes, the radio re-displays "CODE" and you can.
For touchscreen units, the lockout countdown runs in the background. Simply leave the vehicle running or the ignition on ACC for the full hour.
The Display Audio era includes radios using multiple serial prefixes depending on which unit was fitted:
U####L####— base CD radio serial (10 characters, two halves).HBM####— Display Audio 5"/7" and navigation units.913A####— certain Alpine OEM configurations.
Part numbers printed nearby begin with 39100 or 39101 — these are not serials. When in doubt, use the Settings → Device Information menu or the 1+6 button method to retrieve the serial directly from the unit.
On the Display Audio, a rejected code most often means the serial was misread. Both the button method and the settings menu can produce the correct serial — double-check that the serial you submitted was read off the radio unit and not from an online database.
If the code was already entered once and rejected, stop and contact support before trying again — another incorrect entry gets you one step closer to the 60-minute lockout. A no-charge serial reverification can be done on request.