FCM ????

[gwatpe]

Had the message

"FCM temporarily unavailable" The usual warning triangle appeared with the FCM OFF permanently displayed. Holding the FCM button did not operate the function with toggling between off, far and near modes.

Was raining "cats and dogs" at the time.

The very conditions where FCM would be useful, and the PHEV turns it OFF.

I suspect that the same would happen if driving when snowing.

FCM had to be enabled manually and only when driving conditions improved.

Maybe other forum members have seen this happen as well?

 

[wazzad]

Silly question but have you tried cleaning the sensors?

I have no idea what they look like or where they are tbh but had the same issue till I ran my car through a good wash, now it seems to function even in heavy rain.

Could be a coincidence

 

[jaapv]

With radar reception impaired by heavy rain, snow or the sensor being obstructed the system cannot function.

 

[kcphev]

The same thing happened to me recently during a heavy downpour.

It looks like the FCM uses 77GHz, ie a wavelength of 4mm, about the size of a raindrop, so, as jaapv suggested, the function would be impaired by heavy rain. Since this is a safety critical system, Mitsubishi rightly disable it if it cannot be relied upon.

77-110 GHz looks to be the standard for ACC, so this should be a common constraint across other manufacturers...

 

[raymie]

I was just coming to the site to add this same comment.

In my case the FCM and therefore also the adaptive cruise control was knocked out but a little bit of falling snow. It tried to kick back in a few times but went back off straight away and only was working again the next morning.

Not expecting FCM to be knocked offline by such a relatively little bit of weather

 

[jaapv]

Just clean the caked snow from the sensor area.

 

[Bladevane]

Snow and heavy rain seem to knock out the FCM function, at least they do on my 2014 model.

 

[mellobob]

Is the sensor for FCM and adaptive cruise also looking after the auto headlight dim/bright option (which I really like)?

 

[DibbyDibbyDJ]

FCM, Adaptive cruise and AHB all have their own individual sensors

 

[SilverD]

ACC on my old Nissan Qashqai used to cut out in heavy rain as well. Didnt complain, as I felt it was much safer for it not to be on in case of aquaplaining on the odd puddle if there was so much rain.

 

[mellobob]

FCM, Adaptive cruise and AHB all have their own individual sensors

Assuming AHB is the headlights, are they radar or light sensing?

 

[DibbyDibbyDJ]

Automatic High beam. Light sensing

 

[AndyInOz]

Re wet weather and aqua-planning...

I remain very surprised at how stable the car is, even in appalling conditions.

I'm guessing that it is all the extra weight on the tyres.