Nissan Skyline R32 air conditioner self-diagnosis
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
(1) Self-diagnosis set
 
To change from ordinary automatic air conditioner control mode into self-diagnosis mode, depress automatic air conditioner OFF switch for more than five seconds within 10 seconds after turning ignition switch to ON from OFF. Start engine to prevent discharging discharged battery when performing self-diagnosis.
To return to automatic air conditioner control mode from self-diagnostic mode, turn ignition switch OFF, or depress air conditioner switch.
Self-diagnostic program is designed to facilitate detection of a fault. It consists of the following five self-diagnostic steps and one customizing step.
Steps 1-5 can be selected by depressing HOT switch or COLD switch. Steps 5 and 6 can be selected by depressing fan switch. 
NOTE: 
Step 6 is not used for trouble diagnosis.
 
Description of each step
Step 1: Segment check (Display section and LED)
Step 2: Sensor check
Step 3: Mode door position check
Step 4: Actuator operation check
Step 5: Sensor recognition temperature display
Step 6: 
• To set difference between display temperature and sensed temperature 
• To memorize intake port when ignition switch is OFF
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
(2) Step 1 (Display section and LED segment check)
Normal: All display and LEDs are lit. 
Abnormal: Failed portion is not lit.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
(3) Step 2 (Sensor check)
Step 2 is selected by depressing HOT switch (Δ) while in step 1 status.
Microcomputer detects whether each sensor input signal satisfies set conditions, and results are displayed on display section. Normal: '20' is displayed in display section.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
Abnormal: Failed sensor number is displayed. If sensor short-circuit is detected, a minus sign (-) is also indicated. If error is detected in two or more sensors, each sensor number is displayed by flashing twice in turn. 
NOTE:
If vehicle is positioned in dark place or if sunlight is exceptionally strong, then sunload sensor error may be indicated.
 
Display number and corresponding sensor, and judgment criteria
 

Display No.

Sensor

When discon­nected

When shorted

20

(Normal)

-

-

21

Outside air sen­sor

Below -60°C (-76°F)

Above 100°C (212°F)

22

Inside air sensor

Below -60°C (-76°F)

Above 100°(212°F)

23

Water tempera­ture sensor

Below -50°C (58°F)

Above 150°C (302°F)

24

Intake tempera­ture sensor

Below -50°C (-58°F)

Above 100°C (212°F)

25

Sunload sensor

Below 0.030 kW (26 kcal/h, 103

BTU/h)/m2

[0.0028 kW (2.42

kcal/h, 9.6 BTU/

h)/sq ft]

Above 1.323 kW

(1,138 kcal/h, 4,516 BTU/h)m2

[0.1229 kW

(105.72 kcal/h,

419.5 BTU/h)/

sq ft]

26

PBR (Note)

Above 4.9V

Below 0.1V

27

Refrigerant tem­perature sensor

Below -50°C (-58°F)

Above 100°C (212°F)

  

NOTE:
PBR is judged based on air mix door opening of 40%.
(Full cold: 0%, full hot: 100%)
If sensor is judged as faulty in step 2, check single sensor according to "SENSOR INSPECTION", and determine whether failure is in sensor or harness.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
(4) Step 3 (Mode door position check)
Depress HOT switch (Δ) while in step 2 status, and step 3 will be selected.
In this step, mode door actuator operates, and whether input signal from position detection switch is normal is checked by microcomputer, and the results are indicated on display section. 
NOTE:
Approximately 16 seconds are required to complete inspection of all modes.
NORMAL: '30' will be displayed. 
ABNORMAL: Number of faulty modes are displayed. 
If two or more modes are faulty, each mode number is displayed by flashing twice in turn. 
NOTE:
Connector disconnection is indicated by the following pattern: 31 -> 32 -> 34 -> 35 -> 36.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
Display number and corresponding mode
  

Display No.

Mode

Display No.

Mode

30

(Normal)

34

FOOT

31

VENT

35

D/F

32

B/L

36

DEF

   

If any mode is judged as faulty in step 3, it indicates that harness or mode door actuator is faulty.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
(5) Step 4 (Each actuator operation check)
If HOT switch (Δ) is depressed while in step 3, step 4 is selected, and '41' displayed. If AMB switch ([AMB]) is depressed in this status, displayed number will change to 42, 43, ... upon each depression of switch, and return to 41 after 47 is displayed.
Auto amplifier provides specified output to each actuator, blower motor and compressor corresponding to these displayed numbers. Check operation of these units visually, or by listening or feeling vibration.
 
NOTE:
Output to compressor is provided as magnet clutch ON-OFF signal and control valve output signal. Control valve output signal causes compressor swash plate inclination angle to change to control compressor delivery. This can be checked by measuring auto amplifier output voltage using a circuit tester.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
Display number and operation status
  

Display number

Intake door

Air mix door

Mode door

Blower motor

Compressor

Magnet clutch ON-OFF

Output voltage to control valve

41

Inside air

Full cold

VENT

5V

ON

Approx. 1V

42

Inside air

Full cold

VENT

5V

ON

Approx. 4.5V

43

inside air

Full cold

B/L

10.5V

ON

Approx. 2.5V

44

Half-outside air

Full hot

B/L

8.5V

ON

Approx. 2.5V

45

Outside air

Full hot

FOOT

8.5V

ON

Approx. 4.5V

46

Outside air

Full hot

D/F

8.5V

OFF

0V

47

Outside air

Full hot

DEF

12V

ON

Approx. 2.5V

  

If abnormality of any portion is detected in step 4, be sure to perform inspection according to "ACTUATOR INSPECTION" flowchart.
 

Abnormal section

Flowchart

Intake door

1-5 (1) Intake door system

Air mix door

1-5 (2) Air mix door system

Blower motor

1-5 (3) Blower motor system

Compressor

1-5 (4) Compressor system

 

Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
(6) Step 5 (Sensor recognition temperature indication)
If HOT switch (Δ) is depressed while in step 4, then step 5 is selected and '5' is indicated in display section. If AMB switch ([AMB]) is depressed in this status, temperatures sensed by outside air sensor, inside air sensor, suction temperature sensor and refrigerant temperature sensor are displayed in the following sequence.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
If temperature displayed in step 5 is excessively different from actual temperature, check suspected sensor according to "SENSOR INSPECTION".
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
(7) Step 6 (Not used when troubleshooting)
Depress fan switch while in step 5, then step 6 is selected and display appears as shown at left. If fan switch is depressed again, step 5 is selected again.
 
1 Setting difference between indicated temperature and sensed temperature
• If passenger's bodily sensation differs from the temperature set on the display section, then the auto amplifier sensing temperature can be changed with respect to the displayed temperature.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
In this case, depress HOT switch (Δ) or COLD switch in step 6. Each time the switch is depressed, displayed temperature will change by 0.5eC. In this way, sensed temperature can be varied in the range from +3.0 to -3.0°C. 
(Example)
If the sensed temperature is set -3.0°C as shown at left with respect to the set display temperature of 25°C, the auto amplifier sensing temperature will be 22.0°C (25.0-3.0 = 22.0). Thus, the actual temperature is controlled at a level lower than the displayed temperature.
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis
 
2 Memorizing intake door position when turning ignition switch OFF
The intake door position when turning the ignition switch OFF can be memorized, and the air conditioner can be started at the memorized intake door position.
To use this function, depress REC switch in step 6. This will cause the [AUTO] display to go out and the memory function to be activated. Pressing the REC switch again will cause [AUTO] to be displayed and the memory function canceled.
NOTE:
Even if condition (1) or (2) is set in step 6, the set condition will be canceled when the battery is disconnected. If step 6 is set at customer's request, it is necessary to explain this point to the customer.
 
(8) Self-diagnostic procedure flowchart
 
Nissan Skyline GT-R32 air conditioner self-diagnosis
 
Nissan Skyline GT-R32 1-1	air conditioner self-diagnosis