New to this forum 👋🏻
 

21 Plate Galaxy Titanium Diesel, just under 16k on clock. Recent amber spanner comes on when car reaches temperature (says check manual, suggesting Powertrain). Under 3 month Ford Warranty as only had for 3 weeks so taking in tomorrow, but I have read that Ford cars wipe the codes when switched off? 

52 minutes ago, ljc7 said:

..., but I have read that Ford cars wipe the codes when switched off? 

Ya read wrong...

Some codes do get cleared when the ignition is switched off.

Generally any that bring the proper engine warning light (EML) on will not get wiped as they create OBD2 codes.

But the Ford specific codes that trigger warning messages rather than the engine light can be cleared when the ECU does it's self test after switching off the ignition.

Personally I'd thrash it on the way over to Ford in order to heat it up and trigger the fault, then leave it running outside their workshop.  There will definitely be a fault code while the warning is on.  There may not be after switching off.

Agree with @TomsFocus, always read the codes (cheap code reader or, better, Forscan?) when the fault is present before switching off (take photos as evidence in case it clears?)  
We had "Fuel rail pressure high" and limp mode which cleared when switched off but read the code and discussed with dealer - it was a "bad batch" of fuel filters causing the issue (change diesel ones at 2 years?)