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What causes the air conditioning in the 2020 Highlander to blow warm air? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What causes the air conditioning in the 2020 Highlander to blow warm air?

What causes the air conditioning in the 2020 Highlander to blow warm air?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
663 words

Problem Statement

Learn how to diagnose and repair the air conditioning system blowing warm air in the 2020 Toyota Highlander with detailed steps and required tools.

Affected Component
A/C system

Symptoms

  • •Air conditioning (A/C) system blows warm air instead of cold.
  • •A/C compressor may engage but does not produce cold air.
  • •Possible strange noises when the A/C is activated.
  • •Unusual odors may come from the vents.

Diagnostic Steps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •Flashlight
  • •Safety glasses
  • •A/C manifold gauge set
  • •Refrigerant (R-1234yf for 2020 Highlander)
  • •Multimeter
  • •A/C clutch cycling switch
  • •Screwdriver
  • •OBD-II scanner
  • •Fuse puller

Additional Information

Affected Component
A/C system
Difficulty
medium
Severity
medium
Tools Required
9 items

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Back to Generation
Problem Diagnosis: Air Conditioning Blowing Warm Air in 2020 Toyota Highlander
Possible Causes
  1. Low refrigerant level due to leaks.
  2. A/C compressor failure.
  3. Faulty A/C climate control module.
  4. Blocked or dirty cabin air filter.
  5. Electrical issues (blown fuses, bad wiring).
  6. Faulty expansion valve or orifice tube.
  7. Blocked refrigerant lines or condenser.

Step 1: Visual Inspection

  • Tools Required: Flashlight, safety glasses.
  • Check for any visible signs of refrigerant leaks around hoses, compressor, and the condenser. Look for oily residue which may indicate a refrigerant leak.

Step 2: Check Refrigerant Level

  • Tools Required: A/C manifold gauge set, refrigerant (R-1234yf for 2020 Highlander).
  • Connect the high and low side gauges to the A/C service ports.
  • Start the engine and turn the A/C to maximum cooling.
  • Read the pressure on both the high and low sides.
    • Low side should typically be between 25-45 psi (varies with ambient temperature).
    • High side should be between 200-300 psi (varies with ambient temperature).
  • If low side pressure is low, it may indicate low refrigerant.

Step 3: Test the A/C Compressor

  • Tools Required: Multimeter, A/C clutch cycling switch.
  • With the A/C on, check if the compressor is engaging.
  • If not engaging, test the electrical connector for voltage with a multimeter.
  • If voltage is present but the compressor does not engage, the compressor may be faulty.

Step 4: Inspect Cabin Air Filter

  • Tools Required: Screwdriver (if necessary).
  • Locate and remove the cabin air filter (usually found behind the glove box).
  • Inspect for dirt or blockages. Replace if necessary.

Step 5: Check A/C Climate Control Module

  • Tools Required: OBD-II scanner.
  • Use an OBD-II scanner to check for any fault codes related to the A/C system.
  • If codes are present, note them and look up specific procedures for diagnosis based on the code.

Step 6: Inspect Electrical Components

  • Tools Required: Multimeter, fuse puller.
  • Check the A/C fuses in the fuse box. Replace any blown fuses.
  • Inspect wiring for any signs of damage or corrosion.
Repair Instructions

Repair 1: Recharging Refrigerant

  1. If low refrigerant is the issue, evacuate the system using a vacuum pump.
  2. Recharge the system using the appropriate amount of R-1234yf refrigerant.
  3. Recheck pressures to ensure they are within specifications.

Repair 2: Replacing the A/C Compressor

  1. Disconnect the battery.
  2. Remove the drive belt from the A/C compressor.
  3. Disconnect electrical connectors and refrigerant lines (ensure to recover refrigerant if necessary).
  4. Unbolt the compressor from its mounting points and remove it.
  5. Install the new compressor, reverse the removal procedure, and recharge the system.

Repair 3: Replacing the Cabin Air Filter

  1. Remove the glove box or cover to access the cabin air filter compartment.
  2. Remove the old filter and clean the compartment.
  3. Install the new cabin air filter and reassemble the glove box.

Repair 4: Replacing Fuses or Wiring

  1. Replace any blown fuses identified in the previous diagnostic steps.
  2. Repair or replace damaged wiring as needed, ensuring secure connections.
Final Steps
  • After repairs, turn on the A/C system and verify that cold air is being produced.
  • Monitor the system for a few days to ensure the problem does not return.
  • Check for any leaks or issues after recharging the refrigerant.
Conclusion

By following these diagnostic and repair steps, you can effectively address the issue of warm air blowing from the A/C system in your 2020 Toyota Highlander. Always ensure to follow safety protocols and consult the vehicle’s service manual for specifications and detailed procedures.