Air Conditioning Cycle Diagnosis

Air Conditioning Cycle Diagnosis

Condition / Possible Cause Part 1:

Condition / Possible Cause Part 2:

For the execution of the charging and discharging operation in the table, refer to Recovery, Recycling, Evacuating and Charging.

Checking The Refrigerant System With Manifold Gauge

Since Refrigerant-134a (HFC-134a) is used in the air conditioning system in this vehicle, be sure to use manifold gauges, charging hoses and other air conditioning service tools for HFC-134a when checking the refrigerant system.

Conditions:

- Run the engine at idling
- Air conditioning switch is "ON"
- Run the blower motor at "HIGH" position
- Temperature control lever set to "MAX COLD"
- Air source selector lever at "CIRC"
- Open the engine hood
- Close all the doors

Part 1:

Part 2:

Normal Pressure:

- At ambient temperature: approx. 25 - 30 °C (77 - 86 °F).
- At low-pressure side: approx. 147.1 - 294.2 kPa (21.3 - 42.7 psi).
- At high-pressure side: approx. 1372.9 - 1863.3 kPa (199.1 - 270.2 psi). Refer to the table on the refrigerant pressure-temperature relationship.

Condition / Possible Cause Part 1:

Condition / Possible Cause Part 2:

Condition / Possible Cause Part 3:

Connect The Manifold Gauge

Low-pressure hose (LOW) - Suction side

High pressure hose (HI) - Discharge side

Checking The A/C System

1. Run the engine and close all the vehicle doors.
2. Turn A/C switch "ON", set the fan switch to its highest position.
3. Set the air source lever to "CIRC", set the temperature lever to the full cool position.
4. Check the high and low pressure of the manifold gauge.
- Immediately after charging refrigerant, both high and low pressures might be slightly high, but they settle down to the pressure guidelines shown below:
- The ambient temperature should be between 25 - 30 °C (77 - 86 °F).
- The pressure guideline for the high-pressure side is approximately 1372.9 - 1863.3 kPa (199.1 - 270.2 psi).
- The pressure guideline for the low-pressure side is approximately 147.1 - 294.2 kPa (21.3 - 42.7 psi).
- If an abnormal pressure is found, refer to Checking The Refrigerant System With Manifold Gauge in this section.

5. Put your hand in front of the air outlet and move the temperature control lever of the control panel to different positions. Check if the outlet temperature changes as selected by the control knob.