Just spent over $1000 having my entire AC System under the hood replaced, but still experiencing issues.
AC blows cold as long as water is blocked off from heater core.
They tested the Heater Control Valve, said it operated correctly.
They tested the Climate Control Unit ( inside car ) and said it tested bad.
Replaced the bad Climate Control unit with new one, problem still exists.
Going to order new Heater Control Valve and install.
Question though...
Ran the HVAC self test on the Climate Control unit ( inside car )
it coded ( flashed ) 27 98 about 6 times.
I cannot for the life of me find any description of these codes anywhere.
Does anyone know of these codes or where I can find the description of these codes ???

 

Pretty sure the driver's side coolant control valve is shorted to ground. Make sure wiring is not pinched anywhere, if ok valve is defective.