Hello just got a 2008 Mariner Premier AWD hybrid with 97K miles. The AC blows cold but when engine shuts off during electric mode it warms down. From my experience with Escape hybrids when you put the AC on Auto or Defroster or Defroster and Floor the engine stays on to keep AC cold (or heat hot). I double checked the owners manual and it states the same. What could be the possible issues on this?

 

2008 FEH compressor is engine driven only - no electric. If the engine isn't spinning, you're not driving the compressor.

Are you in ECON mode? Is your ECON mode somehow stuck on? If so, that forces the engine to stop if it's only being run for A/C.

http://www.fordservicecontent.com/Fo.../08hevog2e.pdf

pages 13 and 43

 

Turns out the dealership replaced the PCM and HVAC module to get it to operate correctly. The PCM only didn’t repair it so I wonder if the PCM was okay in hindsight.

 

I see u solved issue, for heating with car in ev mode there is a coolant recuirculate pump for cabin heat that can fail also. This would only affect cabin heat in ev mode not cooling. The pump continues to recirculate coolant through heater core when engine is off. A Mercedes idea!