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Home/Mazda/2/Mk3 (DJ/DL) 2015-2022/Open the Hidden Diagnostic Menu

Open the Hidden Diagnostic Menu

These instructions apply to the Mazda 2 Mk3 (DJ/DL) 2015-2022. For other models, please choose your vehicle here.

Last updated: June 11, 2026

The Mazda 2 (Mk3/DJ, 2015–2022) hides an instrument-cluster Test Mode that you can open yourself with no scan tool. Using nothing more than the dash trip-reset button and the ignition, the cluster runs through a full self-check — needle sweep, warning-lamp and LCD test, live sensor values and stored cluster faults — so you can tell a dead gauge from a bad sensor before paying a workshop.

What Test Mode is and what it shows

This built-in routine makes the DJ cluster check itself. It steps through a numbered sequence of tests, each shown as a code in the odometer window. Across the sequence you can see:

  • Every warning LED and indicator lit in turn, plus an LCD segment test for dead pixels
  • Full needle sweeps of the speedometer and tachometer
  • Fuel-gauge and engine-temperature gauge sweeps
  • Live fuel-sender and other input-signal readings as raw numbers
  • The warning chime and turn-signal sound test

Because the cluster is reporting on itself and on the sensors that feed it, a gauge that fails to sweep points at the cluster, while a sweep that works but reads wrong in normal driving points at the sender.

How to enter the hidden diagnostic menu

  1. Switch the ignition fully OFF and sit in the driver’s seat.
  2. Press and hold the trip-reset button on the instrument cluster.
  3. While holding it, switch the ignition to ON (position II) without starting the engine. On keyless DJ models, press the START button twice without touching the brake pedal to reach ON.
  4. Keep the trip button held until TEST appears in the odometer display, then release it.
  5. Tap the trip button to step from one test code to the next.

Reading the gauges and codes

Each press of the trip button advances to the next numbered test. Start with the LED and LCD checks — an unlit lamp or a missing display segment is a cluster fault. The gauge codes drive the needles through their full travel; watch for a needle that sticks or lags. The fuel and temperature readings appear as numeric values, which is the quickest way to confirm whether an erratic fuel gauge is the sender or the cluster. Note any code or value that looks wrong before you leave the mode.

How to exit

Turn the ignition OFF, then back ON, to leave Test Mode. Nothing you viewed is stored or changed, and the cluster returns to normal at the next start.

Frequently Asked Questions

Does this work on the keyless push-button Mazda 2? Yes. Hold the trip-reset button and press START twice without pressing the brake to reach the ON position, then keep holding until TEST shows.

Will Test Mode reset my service or oil light? No. It only reads and displays data. The service indicator and trip meters are left untouched.

Why does TEST not appear? You likely reached START or ENGINE-RUN rather than ON, or released the button too early. Make sure the cluster lights are on but the engine is not running, and keep the trip button held throughout.

Are these the same as engine fault codes? No. Test Mode shows cluster-level data and faults. If the check-engine lamp is lit, follow up with a full OBD-II scan of the engine ECU.

Is it safe to cycle through every test? Yes, with the engine off the tests only drive the gauges and lamps. Do not run the mode while driving.

To look up the meaning of any fault code you record, visit autodtcs.com.

Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.

This website is an independent resource and is not affiliated with, endorsed by, or sponsored by Mazda. All trademarks and brand names belong to their respective owners.

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