Performance Test

The performance test will help determine if the A/C system is operating within specifications.

1. Do the A/C system inspection (see A/C SYSTEM INSPECTION ), and correct any problems found.
2. Connect an R-134a refrigerant recovery/recycling/charging station to the high-pressure service port and the low-pressure service port, following the equipment manufacturer's instructions.
3. Determine the relative humidity and air temperature.
4. Open the glove box. While holding the glove box, release the glove box stops on each side from the dashboard by pushing them in, then lower the glove box (see step 1 on GLOVE BOX STRIKER REPLACEMENT ).
5. Insert a thermometer (A) in the center vent.
   Fig 1: Inserting Thermometer In Center Vent

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
6. Place another thermometer (B) near the blower unit's recirculation inlet duct.
7. Test conditions:
   • Move the vehicle out of direct sunlight and let it cool down to the surrounding (ambient) temperature. If necessary, wash the vehicle to cool it down more quickly.
   • The ambient blower intake temperature must be at least 68°F (20°C).
   • Open the hood.
   • Open the front doors.
   • Set the temperature control dial to Max Cool, the mode control button to Vent, and the recirculation control button to Recirculate.
   • Turn the A/C switch ON and the fan control switch to Max.
   • Hold the engine speed at 1, 500 rpm.
   • No driver or passengers in the vehicle.
8. Inspect the A/C components for the following conditions:
   • A/C compressor clutch not engaged.
   • Abnormal frost areas.
   • Unusual noises.

   If you observe any of these conditions, refer to the Symptom Troubleshooting Index .

9. After running the air conditioning for 10 minutes under the above test conditions, read the delivery temperature from the thermometer in the center vent, the intake temperature near the blower unit, and the high and low system pressure from the A/C gauges.
10. To complete the vent (delivery)/intake temperature chart:
    • Mark the vent (delivery) temperature on the vertical line.
    • Mark the intake temperature on the bottom line.
    • Draw a vertical line from the intake temperature mark.
    • Draw a horizontal line from the vent (delivery) temperature mark until it intersects the vertical line.
    NOTE: The vent temperature and the intake temperature should intersect in the shaded area. Any measurements outside the area may indicate the need for further inspection.
    Fig 2: Intake Temperature VS. Vent (Delivery) Temperature Graph

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
11. To complete the high side (discharge) pressure/intake temperature chart:
    • Mark the high side (discharge) pressure on the vertical line.
    • Mark the intake temperature on the bottom line.
    • Draw a vertical line from the intake temperature mark.
    • Draw a horizontal line from the high side (discharge) pressure mark until it intersects the vertical line.
    NOTE: The high side pressure and the intake temperature should intersect in the shaded area. Any measurements outside the area may indicate the need for further inspection.
    Fig 3: Intake Temperature VS. High Side (Discharge) Pressure Graph

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
12. To complete the low side (suction) pressure/intake temperature chart
    • Mark the low side (suction) pressure along the vertical line.
    • Mark the intake temperature along the bottom line.
    • Draw a vertical line from the intake temperature mark.
    • Draw a horizontal line from the low side (suction) pressure mark until it intersects the vertical line.
    NOTE: The low side pressure and the intake temperature should intersect in the shaded area. Any measurements outside the area may indicate the need for further inspection.
    Fig 4: Intake Temperature VS. Low Side (Suction) Pressure Graph

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
    PRESSURE TEST
    
    

    Test results	Related symptoms	Probable cause
    Driver and passenger's side A/C vent temperatures may vary by approx. 52°F (11°C) or more.	Suction pressure may be low.	Low refrigerant charge. Expansion valve not opening sufficiently
    Discharge pressure abnormally high.	Discharge pressure reduced when A/C condenser cooled with water spray. With doors open, fresh air selected and radiator and A/C condenser fan run on high speed, temperature drop across A/C condenser inlet to outlet is less than about 41°F (5°C).	Significant refrigerant overcharge.
    	Restricted/weak airflow through A/C condenser.	Dirty A/C condenser or damaged fins. Debris between A/C condenser and radiator. One or more cooling fans malfunctioning.
    Discharge pressure abnormally low.	Suction and discharge pressures equalize rapidly after stopping compressor. Suction pressure higher than normal.	Faulty A/C compressor discharge valve or seal.
    Suction pressure abnormally low.	Weak or insufficient airflow across evaporator.	Restricted blower intake or pollen filter.
    	Suction pressure varies from near normal to a vacuum, as moisture freezes in expansion valve orifice.	Moisture in the system. Faulty expansion valve.
    	Reduced airflow from vents. Vent temperature is very low.	Condensation freezing on evaporator. Faulty evaporator temp sensor (check DTC). Faulty expansion valve or compressor relay.
    Suction pressure abnormally high.	Lack of slight suction pressure variation at 1, 500 RPM when "Recirculated" airflow is switched to "Fresh Air". Discharge pressure near normal.	Expansion valve stuck open or open too long.
    Suction and discharge pressures abnormally high.	Sheet of paper does not stick to front of A/C condenser surface with cooling fans on. With doors open, fresh air selected and radiator and A/C condenser fan run on high speed, temperature drop across A/C condenser inlet to outlet is less than about 41°F (5°C).	One (or both) cooling fan motor inoperative or wires reversed.
    	A/C compressor clutch remains engaged during off cycle. Pressure relief valve may open.	Insufficient compressor clutch clearance. Compressor relay or circuit problem. Excessive air in system.
    Suction and discharge pressures abnormally low.	Suction line from expansion valve to compressor is not cold.	Excessively low refrigerant charge.
    	Lack of slight suction pressure variation at 1, 500 RPM when "Recirculated" airflow is switched to "Fresh Air".	Expansion valve clogged with debris/desiccant, stuck closed, or not opening sufficiently.
    	More than 50-60°F (10-16°C) temperature drop across A/C condenser inlet to outlet pipes.	Blocked or restricted A/C condenser internal passages or lines/components restricting refrigerant flow.
    	Significant temperature difference along high or low side A/C lines or components. NOTE: Some restrictions may not show up until 3, 000 RPM.	Restriction in A/C suction or discharge lines or components (check temperatures to isolate).
    Suction pressure high and discharge pressure low.	Excessive A/C compressor noise. Pressures equalize quickly and noise after compressor turns off.	A/C compressor internal damage (Check for A/C system debris contamination).
    Suction and discharge pressures normal (or near normal).	Vent temperature too high.	Slightly low refrigerant charge. Air mix door sticking, misadjusted or inoperative. Excessive refrigerant oil in system. Heater valve (if equipped) misadjusted.
    	Static pressures high with A/C system equalized. (After engine is off 4-12 hours).	Air/non-condensable gasses in system. Contaminated or incorrect refrigerant.