HVAC System Check (CJ2)
Step
| Action
| Normal Result(s)
| Abnormal Result(s)*
|
1
|
- Install the scan tool.
- Turn the ignition switch to the ON position.
- Select display DTC function with the scan tool.
- Check for any stored HVAC, PCM or BCM DTCs related to HVAC operation.
| No DTCs
are stored in memory or current status.
|
| • | DTC is stored in memory or current status (refer to appropriate
DTC table). |
|
2
|
- Turn ignition to the OFF position.
- Remove the scan tool from the diagnostic link connector.
- Start the engine and allow the vehicle to idle in Park until the
engine reaches operating temperature.
- Close the vehicle doors and windows.
- Engine decklid in the closed position.
- Press the HVAC mode control button until the UPPER air delivery
position is reached.
- Turn the blower switch to position four.
- Turn the driver's side temperature control knob to the 32°C
(90°F) position.
- Press the A/C button so that it is in the OFF position.
- Press the OUTSIDE AIR button to the ON position.
- Install an accurate thermometer into the UPPER air outlet.
|
| • | Air flows from the instrument panel outlets. |
| • | Hot air is delivered to passenger compartment. |
| • | Blower fan operates at medium speed. |
| • | Delivered air temperature is approximately between 63°C and
68°C (145°F and 155°F) measured in typical garage settings (21°C
to 24°C (70°F to 75°F)). |
|
|
3
|
- Doors and windows still closed.
- Engine decklid in the closed position.
- Depress the A/C button to the ON position.
- Depress the AUTO button.
- Turn the driver's side temperature control knob to the maximum
cold position.
- Thermometer still installed in the UPPER air outlet.
|
| • | Air flows from the instrument panel outlets. |
| • | A/C light illuminates and compressor is engaged. |
| • | Cold air is delivered to passenger compartment. |
| • | Blower fan operates at maximum speed. |
| • | Delivered air temperature is approximately 18°C (30°F)
lower than ambient air temperature. |
| • | Air delivery may switch between RECIRC and OUTSIDE AIR position. |
|
|
4
| Depress
the fan control button until the fan reaches low speed.
|
| • | Blower speed decreases as long as fan control button is depressed. |
| • | Blower speed is displayed. |
| • | Blower runs at speed attained when fan control button is released. |
|
|
5
| Depress
the fan control button until the fan reaches high speed.
|
| • | Blower speed increases as long as fan control button is depressed. |
| • | Blower speed is displayed. |
| • | Blower runs at speed attained when fan control button is released. |
|
|
6
| Rotate
the driver's side temperature control knob until the temperature display reaches
22°C (73°F).
|
| • | Driver's set temperature display drops one degree at a time (stops
at 22°C (73°F)). |
| • | Blower speed reduces as in-car temperature approaches 22°C
(73°F). |
| • | A/C system maintains in-car temperature at approximately 22°C
(73°F). |
| • | Air delivery may switch between the UPPER, BILEVEL, DEFOG and
LOWER position depending on ambient conditions. |
| • | Air delivery may switch between RECIRC and OUTSIDE AIR position
depending on ambient conditions. |
|
|
7
|
- Allow the car to idle for 5-10 minutes in the AUTO setting with
the temperature at 22°C (73°F).
- Rotate the passenger's side temperature control knob to the maximum
heat position.
- Rotate the passenger's side temperature control knob to the maximum
cold position.
- Return the passenger's side temperature control knob to the neutral
position.
|
| • | Passenger's side air flow becomes warmer then the master setting. |
| • | Passenger's side air flow becomes cooler then the master setting. |
| • | Passenger's side air flow returns to the master setting. |
|
|
8
|
- Depress the mode control button until the instrument panel UPPER
position is displayed.
- Rotate the driver's side temperature control knob until the temperature
display reaches 15°C (60°F).
- Push the A/C button to the OFF position.
- Depress the OUTSIDE AIR control button.
|
| • | Air flows from the panel outlets. |
| • | Outside (ambient temperature) air is delivered to passenger compartment |
|
|
9
| Depress
the mode control button until the LOWER floor position is displayed.
|
| • | Air flows from the floor outlets. |
|
|
10
| Depress the mode control button until the DEFOG position is displayed.
|
| • | Air flows from the floor and windshield outlets. |
| • | A/C compressor is engaged with ambient temperature greater than
2°C (35°F). |
|
|
11
| Depress the mode control button until the BILEVEL position is displayed.
|
| • | Air flows from the instrument panel and floor outlets. |
|
|
12
| Depress the front window DEFROSTER button.
|
| • | Air flows from the windshield outlets. |
| • | A/C is engaged with ambient temperature greater than 2°C (35°F). |
|
|
13
|
- Depress the mode control button until the UPPER position is displayed.
- Depress the A/C button to the ON position.
- Rotate the driver's side temperature control knob until the temperature
display reaches 15°C (60°F).
- Depress the RECIRC control button.
|
| • | Air flows from the instrument panel outlets. |
| • | Air recirculates within the vehicle. |
|
|
14
|
- Depress the A/C button to the OFF position.
- Depress the OUTSIDE AIR control button.
|
| • | Air flows from the instrument panel outlets. |
| • | Outside air circulates into the vehicle. |
|
|
15
| Depress the OFF button.
|
| • | Outside air temperature is displayed on the HVAC control panel
after a five second display of driver's set temperature. |
|
|
* Refer to the appropriate symptom diagnostic table for
the applicable abnormal result.
|
