TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
15 Y/L Air conditioner relayEngine is running.
Air conditioner switch is ``OFF''.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Both air conditioner switch and blower fan
switch are ``ON''.
(Compressor is operating.)0-1V
ON BOARD DIAGNOSIS LOGIC
This diagnosis continuously monitors the engine coolant temperature.
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Diagnostic Trouble
Code No.Malfunction is detected when ...Check Items
(Possible Cause)
28+Cooling fan does not operate properly (Overheat).
+Cooling fan system does not operate properly (Over-
heat).
+Engine coolant was not added to the system using
the proper ®lling method.+Harness or connectors
(The cooling fan circuit is open or shorted.)
+Cooling fan
+Radiator hose
+Radiator
+Radiator cap
+Water pump
+Thermostat
+Fan belt
+Engine coolant temperature sensor
For more information, refer to ``MAIN 12
CAUSES OF OVERHEATING'', EC-120.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in the MA
section (``Changing Engine Coolant'', ``ENGINE MAINTENANCE''). Also, replace the engine oil.
a. Fill radiator with coolant up to speci®ed level with a ®lling speed of 2 liters per minute. Be sure to
use coolant with the proper mixture ratio. Refer to MA section (``Anti-freeze Coolant Mixture Ratio'',
``RECOMMENDED FLUIDS AND LUBRICANTS'').
b. After re®lling coolant, run engine to ensure that no water-¯ow noise is emitted.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)
Cooling Fan (Overheat) (Cont'd)
EC-114
