how to fix the air conditioning not working in my Toyota Highlander Third Generation (2014-2019)

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

3 min read

577 words

Problem Statement

Learn how to diagnose and fix the air conditioning not working in your Toyota Highlander (2014-2019). Step-by-step guide with symptoms and solutions.

Affected Component

HVAC

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical components.
•Allow the engine to cool before inspecting the AC system.

Symptoms

•No cold air blowing from the vents
•Air conditioning system making unusual noises
•Inconsistent temperature from the AC
•AC compressor not engaging
•Visible leaks around AC components
•Dashboard warning light related to the AC system illuminated

Diagnostic Steps

1
Inspect the AC system for any visible leaks or damage to hoses and components.
2
Check the refrigerant level using a pressure gauge.
3
Use an OBD-II scanner to check for any error codes related to the AC system.
4
Inspect the AC compressor clutch for engagement while the system is turned on.
5
Test the AC relay and fuses for proper operation.
6
Check the cabin air filter for clogs or restrictions.

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

•Socket set
•Screwdrivers
•Refrigerant pressure gauge
•OBD-II scanner
•Multimeter

Parts Required

•Refrigerant (R-134a)
•AC compressor (if faulty)
•AC relay (if faulty)
•Fuses (if blown)

Related Faults

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Diagnostic Steps

1
Inspect the AC system for any visible leaks or damage to hoses and components.
2
Check the refrigerant level using a pressure gauge.
3
Use an OBD-II scanner to check for any error codes related to the AC system.
4
Inspect the AC compressor clutch for engagement while the system is turned on.
5
Test the AC relay and fuses for proper operation.
6
Check the cabin air filter for clogs or restrictions.

Solution

1. Preparation

Tools Required: Socket set, screwdrivers, refrigerant pressure gauge, OBD-II scanner, multimeter.
Ensure the vehicle is parked on a level surface.
Disconnect the negative terminal of the battery for safety.

2. Refrigerant Level Check

Locate the low-pressure service port of the AC system.
Connect the refrigerant pressure gauge to the service port.
Check the pressure reading against the manufacturer's specifications.
- If low, proceed to recharge the system; if adequate, move to the next step.

3. Recharge the AC System (if necessary)

Using a refrigerant canister with a hose, connect it to the low-pressure service port.
Follow the instructions on the refrigerant canister for adding the refrigerant.
Start the engine and turn on the AC to the maximum setting while adding refrigerant.
Monitor the pressure gauge and ensure it reaches the correct level.

4. Inspect AC Components

Reconnect the battery terminal.
Start the vehicle and turn on the AC.
Check the AC compressor clutch by observing if it engages when the AC is turned on.
If not engaging, use a multimeter to check for voltage at the compressor connection.

5. Replace Faulty Components

If the AC compressor is not engaging, replace the AC compressor or the relay if testing indicates a failure.
If any fuses are blown, replace them with the same amperage rating.

6. Reassemble and Test

Reassemble any components removed during inspection.
Start the vehicle and turn on the AC to test functionality.
Ensure cold air is now blowing from the vents.