The near side (passenger) electric mirror on my 2015 grand c max was smashed. I ordered a replacement from a big uk supplier, but when fitted the temp sensor and reversing sensors do nor operate. Re fitting the old harness restores function. 

Is this a normal wiring arrangement , if so I guess the part is unsuitable??

Very strange as those sensors are no where near the mirror.

38 minutes ago, pragmatix said:

Very strange as those sensors are no where near the mirror.

The ambient air temp sensor is in the n/s door mirror

2 hours ago, iantt said:

The ambient air temp sensor is in the n/s door mirror

Not on mine it isnt but mine is the nwer version., still don't understand the reverse sensors though.

You sure It isn't? 

I don't understand the reverse sensors though. 

According to etis it's in the mirror housing, and the mirror connector c521 on pin 11 . That's grand cmax/cmax 2015 onwards. 

25 minutes ago, iantt said:

You sure It isn't? 

I don't understand the reverse sensors though. 

According to etis it's in the mirror housing, and the mirror connector c521 on pin 11 . That's grand cmax/cmax 2015 onwards. 

 Well,i had that mirror swiped of the car and still had outside temp i think dont recall it missing. But im willing to be proved wrong. 

The car is late 2015(nov) and temp sensor definitely in mirror as the thermocouple worked when the harness was hanging loose after mirror smashed off. Also re connecting  and disconnecting wiring activated and halted reversing sensors?.

Just thinking about the reverse sensors does you car have the all round sensors like mine does maybe the mirror plays a part in that system and its the wrong mirror

Does your car have the blind spot indicator?  If so, I think there is a radar sensor in the mirror which I would assume is also used by the parking sensors for auto-parking. 

With regards to the temp sensor, I have seen them both in the mirror housing and by the front bumper, I'm not sure if they changed location at some point or if both are fitted and an average taken between the two to remove the inaccuracies of parking in direct sunlight etc.

26 minutes ago, TomsFocus said:

Does your car have the blind spot indicator?  If so, I think there is a radar sensor in the mirror which I would assume is also used by the parking sensors for auto-parking. 

With regards to the temp sensor, I have seen them both in the mirror housing and by the front bumper, I'm not sure if they changed location at some point or if both are fitted and an average taken between the two to remove the inaccuracies of parking in direct sunlight etc.

That makes sense and is what i was trying to say

No blind spot sensor, but logically mirror and reversing sensors are a linked function ( I.e. going backwards views).However, I bought a new unit from ford dealer, fitted and all functions restored fine, so there is a wiring connection!

now just returning the wrongly specced unit which was cheaper, but no good if unsuitable!

cheers!

 

13 minutes ago, EddyR said:

No blind spot sensor, but logically mirror and reversing sensors are a linked function ( I.e. going backwards views).However, I bought a new unit from ford dealer, fitted and all functions restored fine, so there is a wiring connection!

now just returning the wrongly specced unit which was cheaper, but no good if unsuitable!

cheers!

 

Glad youve got it sorted.

Interesting - I too have a 2015 Grand C-Max 1.5TDCi (120hp) and need to look into how to access the outside-temp sensor in the LH (nearside) door mirror. Three Ford dealers told me very recently that the whole mirror unit has to be replaced, at between €400 (in France) and £200 (UK) - but I see one can obtain a replacement sensor, so... My dash outdoor-temp sensor has been giving wildly inflated readings all summer, and at the same time the engine cooling fan has been running excessively. I think there's a connection. Ford dealers have proved disturbingly vague about this - I don't think they have a clue.

@tonyharrrison did you solve issue? I have same problems since last 5 days... outside is around 0 C,and on display 42C, engine cooling fan working

Any news? 
 

i really don’t want to pony up for a new wing mirror if there’s some clever button sequence that recalibrates the ambient temp sensor

 

 cheers!