Kia Carens: Heater / PTC Heater (Diesel only) Description and operation
The PTC (Positive Temperature Coefficient) heater is installed at the exit or
the backside of the 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 the 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
|

Replacement
1.
Disconnect the negative (-) battery terminal.
2.
Remove the heater and blower assembly.
(Refer to Heater -" ...
Inspection
Operating Logic Test (Manual only)
Inspect the PTC operation with the confirmation logic below :
1.
Entering
(1)
...
Other information:
Inspection
1.
Turn ignition switch OFF and disconnect the negative (-) battery cable.
2.
Remove the fuse box cover.
3.
Remove the starter relay (A).
4.
Check for c ...
Description
Rail Pressure Sensor (RPS) is installed on the delivery pipe and measures the
instantaneous fuel pressure in the delivery pipe. The sensing element (Semiconductor
element) built in the sensor converts the pressure to voltage signal. By using
this signal, the ECM ...