Kia Sportage: Heater / PTC Heater Description and operation
The PTC (Positive Temperature Coefficient) heater is installed at the exit or
the backside of heater core.
The PTC heater is an electric heater using a PTC element as an auxiliary heating
device that supplements deficiency of interior heat source in highly effective
diesel engine. The electric heater heats up the interior by directly heating
the air that passes through the heater. The name itself implies that the element
has a proportional resistance change sensitive to temperature.

Operation Principle
ECM outputs a PTC ON signal and operates PTC relay 1. Then heater controller
operates PTC relay 2 and PTC relay 3 with an interval of 15 seconds.
However, PTC relay 3 can be operated while battery voltage is above 12.4V.
Operating Condition
PTC heater operates according to the following conditions;
• |
Battery voltage: 12.4V or above
|
• |
Ambient temperature and coolant temperature
|
Ambient
Temperature
|
Coolant
Temperature
|
PTC
Operation
|
Below -20°C
(-4°F)
|
Below 75°C (167°F)
|
ON
|
10°C (504°F)
|
Below 65°C (149°F)
|
ON
|
12°C (53.6°F) or above
|
-
|
OFF
|
-
|
80°C (176°F) or above
|
OFF
|

Replacement
1.
Disconnect the negative (-) battery terminal.
2.
Recover the refrigerant with a recovery/recycling/charging station.
...
Inspection
Operating Logic Test (Manual only)
Inspect the PTC operation by confirmation logic as follows;
1.
Entering
(1)
Se ...
Other information:
Always observe the following:
Check tire pressure when the tires are cold. (After the vehicle has been
parked for at least three hours or hasn't been driven more than one mile (1.6
km) since startup.)
Check the pressure of your spare tire each time you check the pressure
of other ...
Replacement
Put on gloves to protect your hands.
•
Use a plastic panel removal tool to remove inter ...