Self-Diagnosis

Self-diagnosis








CHECKING PROCEDURE

STEP 1: Checks LEDS and segments





When switch's LED and segments are in good order in STEP 1 mode, the corresponding LED and fluorescent display tube will illuminate.





If LEDs or segments malfunction, LED does not come on or display shows incomplete segment.





STEP 2: Checks each sensor circuit for open or short circuit
Display shows "2 "in STEP 2 mode.
When all sensors are in good order, display shows "20". It takes approximately 4 seconds to check all sensors.
If a circuit is shorted, display shows ECON mark blinks on display.





If two or more sensors malfunction, corresponding code Nos. respectively blink two times.





Sensors and abnormalities
If a circuit is opened or shorted, display shows its code No. when input corresponds with any of following conditions.

STEP 3: Checks mode door operation





Display shows "3 "in STEP 3 mode.
When all doors are in good order, display will then show "30"
It takes approximately 16 seconds to check all mode and intake doors.





When abnormalities are detected, display shows a code No. corresponding with malfunctioning circuit, door position switch or motor.





If any mode and intake door motor position switch is malfunctioning, mode and intake door motor will also malfunction.





If two or more mode and intake doors are out of order, corresponding code numbers respectively blink two times.

STEP 4: Checks operation of each actuator





Start engine and run at operating temperature.
Display shows "41 "in STEP 4 mode. When 6 (DEF) switch is pressed one time, display shows "42". Thereafter, each time the switch is pressed, display advances one number at a time, up to "46", then returns to "41".

The auto amplifier will forcefully transmit an output to the affected actuators in response to code No. shown on display, as indicated in table below.





Checks must be made visually, by listening to any noise, or by touching air outlets with your hand, etc. for improper operation.





Operating condition of each actuator cannot be checked by indicators.





STEP 5: Checks temperature detected by sensors
Display shows "5 "in STEP 5 mode.





- When (DEF) switch is pressed one time, display shows temperature detected by ambient sensor.
- When (DEF) switch is pressed second time, display shows temperature detected by in-vehicle sensor.
- CON indicates display shows negative temperature reading.
- When (DEF) switch is pressed third time, display returns to original presentation "5"




If temperature shown on display greatly differs from actual temperature, check sensor circuit at first then inspect sensor itself according to the procedures described in Control System Input Components.





AUXILIARY MECHANISM: Temperature setting trimmer
This trimmer compensates for differences in a range of ±3°C (±6°F) between temperature setting (displayed digitally) and temperature felt by driver.

Operating procedures for this trimmer are as follows:
- Begin Self-diagnosis STEP 5 mode.
- Press the (fan) UP switch to set system in auxiliary mode.
- Press either (HOT) or (COLD) switch as desired. Temperature will change at a rate of 0.5°C (1°F) each time a switch is pressed.

When battery cable is disconnected, trimmer operation is canceled and temperature set becomes that of initial condition, i.e. 0°c (0°F).