Gearbox Warning Light

The gearbox may switch to an emergency mode with only one or a few gears. Heavy towing, steep hills and stop-start traffic can overheat the fluid. Some cars show a text message instead of a symbol. Using the correct fluid specification is essential when the gearbox is serviced.

The transmission control unit detects sensor, solenoid or temperature problems and limits operation to protect the gearbox.

If it warns of overheating, stop and let the gearbox cool down with the engine idling or off, as the manual says. Have the fault codes read before the damage gets worse.