Hi Folks,

 

First post here. I've got an issue with our S-max 2018 2.0 TDCi with Sync 3. The external temperature is wrongly displayed and always seems to be 18 degrees or close to it. Sitting outside with a thermometer tells me it's wrong.

 

I've tried pressing the AC and recirc buttons together, explored the "hidden menu" on Sync 3 and tried a master reset to no avail.

 

Any useful tips or pointers appreciated.

7 minutes ago, smaxthat said:

The external temperature is wrongly displayed and always seems to be 18 degrees

Please post photo of the display.

Hello,

 

It's a SYNC 3 unit, software version 3.0, with AC. The temperature is in centigrade as confirmed by the instrument cluster.

Was there anything in particular to clarify?

 

Thanks for the photo.

I see today it is showing 16^oC so it does change. What temperature should it have been showing ?

It always seems to be about 6 degrees out in either direction. I've located the "ambient temperature sensor" in the front grille and suspect it may be out of tolerance. 

It seems that Ford sells a lot of these. 

Previously no issues with ambient external temperature. Normally, I would ignore this but it plays with the heating/cooling system and I've got 3 kids.

Anyone replaced one on an S-max or Galaxy?

You might find this interesting to read through, especially the last post from Krista, which if true means its not the sensor !!

Krista said "The fix was a new air conditioning condenser. Took mine into an AC specialist today who has confirmed I need a new condenser."

I have may doubts but perhaps the poster will return to confirm when the system has been repaired.

 

Thanks for the suggestions. I think I'll replace the ambient temperature sensor first and see what happens. Live data tracing does appear to show reaction to a towel soaked in hot water but I think it's just a simple thermistor. 

If it gets worn/out of tolerance then the temperature will be wrongly displayed. 

The car is going to the mechanic on Monday and I'll ask them to swap a new one in whilst the front under-tray is off.

I will update after that.

So, ambient temperature sensor replaced with a brand new Ford part today. Live trace shows a much better profile with quite active response compared to the old one and close to external actual temperature.

 

However, the display on the Sync 3 unit will not change.

 

In summary, it seems to be Sync 3 software issue rather than a hardware one as the live data proves that accurate figures are now being fed through to the system. 

 

Curious. 

Just to close this off, I replaced the ambient external temp sensor and the internal one and upgraded to SYNC 3.4 (much nicer!).

The issue turned out to be a failing main battery. Fitted with an AGM one from factory, replaced with a new one (096 size AGM), reset the BMS and everything is working again.

I hope this helps someone!

Don't forget to order replacement cable ties with fir tree adapter to secure the cables back into place. eBay or Aliexpress are good sources if you can wait for delivery and identical to Ford ones.