If the warning is being shown when the engine is first started (and therefore, patently not overheating) the fault is likely to be with an engine sensor that tells the computer the engine temperature. This model is known for this fault.

However, if the engine really is overheating, the possible causes are many and could be a stuck thermostat, a blocked radiator, a leak in the cooling system, a failed EGR valve, a failing water pump, or perhaps even something less obvious like a blown head gasket.

So the first step is to determine whether the engine really is overheating or not and go from there. An experienced mechanic will tackle each possibility in turn, but make sure they’re aware of the sensor problem with this model.

It’s not uncommon to find unused electrical connectors inside the cabin and engine bay of modern cars. You may find, for instance, that your car is a mid-spec model with electrical adjustment of the front seats (which explains the two connectors that are wired up). But further up the range, there’s a more expensive model with, say, heated front seats that yours doesn’t have. But the wiring loom is the same in both versions of the car, so the connector for the heated seats is present in your car, but has nothing to connect to. If that’s the case, then this is very unlikely to cause a starting problem.

However, a lot of modern cars also position their computers under the seat, inside the cabin. If somebody has removed the seats or fiddled about down there and either dislodged or not reconnected a plug for the computer, then this could definitely cause all sorts of running and starting issues. If you’re still in doubt, most workshops should be able to identify what the connector is and whether it needs to be reconnected or simply left alone.

Ultimately, you may have to resort to a locksmith to have the key fob re-synced with the car. But before you do that, try this: Mitsubishis of this era often have a key fob with a lock and unlock button. While sitting in the car (or standing next to it) push both lock and unlock buttons down together. Hold them down until you see the fob’s LED flash three times. Then, push the unlock button for one flash of the LED. The LED should then flash another two times and you’re all set. The lock and unlock buttons should now work.

It may not work with all cars, but it’s definitely worth a try. If it doesn’t, you probably have a Mitsubishi model where syncing has to take place via the OBD (On-Board Diagnostics) plug which requires a bit more know-how and the correct plug tools. That’s where your friendly locksmith or auto electrician comes in.