2013 C-Max Hybrid No Heat unless your driving

[flipper]

2013 C-Max Hybrid.  

 

No heat unless I am driving steady on the highway.  Once I stop or slow down, the air turns cold.  

I checked the coolant level and it is full.  The actuators all seem to be working. 

 

Any suggestions?

 

 

[jestevens]

The hybrid version does get cabin heat from the engine ... It should run the engine even if you aren't driving if there is large demand for heat in the cabin when it's cold out.

 

You'd think a stuck thermostat or something like that would set a code. 

 

Maybe heater core is plugged or air in radiator?  I'm by no means a mechanical genius. 

[jestevens]

Here is a video that may help...
 

 

[cr08]

Good video. Another recommendation, and this may sound like a broken record here but is always a good, easy, and quick check for these vehicles: Scan for any codes. Get a cheap OBD dongle (one that can read MS-CAN! This is relevant for HVAC stuff) and use Forscan to get all Ford specific codes. These vehicles track and document a ton of stuff even if it doesn't trigger a warning light. This can include any HVAC malfunctions like the blend doors. There's also a number of sanity checks it does for coolant flow/temp stuff that will store trouble codes. Very easy and quick check and can potentially help narrow down the issue before getting into manual diagnostics.

 

Anecdotally a relative of mine recently purchased a 2015 Explorer with vent selection issues being stuck on face vents only. While an obvious cause there, the HVAC module has clearly reported a malfunction with that actuator. And because it is not emissions related, it doesn't produce a CEL or any other warning lights.

Edited November 7, 2023 by cr08