These instructions apply to the Ford Mondeo Mk5 (CD391) 2014-2022.
For other models, please choose your vehicle here.
The Ford Mondeo (Mk5, 2014–2022) includes the owner-accessible instrument cluster Self-Diagnostic Mode common to modern Fords, sometimes called engineering test mode. You open it with the steering-wheel OK button and the ignition — no scan tool — to run a gauge sweep, check the display and warning lamps, read live engine data and view stored cluster fault codes from the driver’s seat.
What the self-test is and what it shows
This hidden routine drives the Mk5 cluster through a self-check sequence: a gauge needle sweep, an LCD test that lights the display, and an indicator-bulb check. It then steps through diagnostic and live-data screens covering:
- ROM level, NVM (EEPROM) level and DTC revision level — cluster reference data
- Stored cluster Diagnostic Trouble Codes (DTCs), or "nOnE" if clear
- Road speed and engine speed (RPM)
- Engine coolant temperature and battery voltage
- Fuel level and fuel flow
It is the cluster reporting on itself and the sensors feeding it — a quick, free first check before booking diagnostics.
How to enter the hidden diagnostic menu
- Sit in the Mondeo with the doors closed and the ignition fully OFF.
- Press and hold the OK button on the left-hand steering-wheel control cluster.
- While holding OK, switch the ignition from position 0 to position II (ON). On keyless cars, press START once with your foot OFF the brake so accessories power up only — do not start the engine.
- Let the dash show the seatbelt / welcome info first, keeping OK held, until TEST appears.
- Release OK within about three seconds of TEST showing, or the cluster exits the mode.
Reading the gauges, voltage and codes
Press the OK button to move through or skip each test. Start with the gauge sweep, LCD illumination test and indicator-bulb check — a missing segment or unlit lamp points to a cluster hardware fault rather than a sensor. Continue past the ROM, NVM and DTC revision-level screens to the live-data pages for road speed, RPM, coolant temperature, fuel flow and battery voltage. With the engine off, a healthy battery reads around 12.4–12.7 V. The DTC screen lists any stored cluster codes or shows "nOnE" when clear; note them before exiting.
How to exit
Turn the ignition to OFF to leave Self-Diagnostic Mode. The cluster returns to normal at the next start and nothing you viewed has been altered.
Frequently Asked Questions
Does this work on the Mondeo Hybrid? Yes. The Self-Diagnostic Mode reports on the instrument cluster and its 12 V supply, so the OK-button entry is the same on petrol, diesel and hybrid Mk5 Mondeos.
The dash shows seatbelt info first — do I let go of OK? No, keep OK held through the seatbelt and welcome screens. TEST appears after they clear; release only then, and within about three seconds.
What do the ROM and NVM screens mean? They show the cluster’s software and stored-data reference levels, useful to a technician confirming the cluster configuration. Most owners can simply skip past them.
Will this reset the service indicator? No. The self-test only reads and displays; the service reminder and trip meters are untouched.
Are the DTCs the same as a check-engine scan? Not quite — they are cluster-level codes. If a powertrain warning lamp is lit, run a full OBD-II scan of the engine ECU as well.
To decode any cluster trouble codes you record and judge how serious they are, visit autodtcs.com.
Independent guide — not affiliated with Ford. Always follow your official service manual and safety precautions. Read our full disclaimer.