why does my Toyota Highlander Third Generation (2014-2019) AC not blow cold air anymore

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

3 min read

563 words

Problem Statement

Learn how to diagnose and fix AC not blowing cold air in Toyota Highlander (2014-2019). Step-by-step guide with diagnostic procedures and repair instructions.

Affected Component

HVAC

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical components.
•Wear safety glasses and gloves when handling refrigerant and working with AC components.

Symptoms

•AC compressor not engaging
•Warm air blowing from the vents
•Unusual noises coming from the AC system
•AC system cycling on and off frequently
•Poor airflow from the AC vents

Diagnostic Steps

1
Check the AC system for visible leaks, particularly around the condenser and compressor.
2
Use an OBD-II scanner to check for any error codes related to the AC system.
3
Inspect the AC compressor clutch to determine if it is engaging when the AC is turned on.
4
Measure the refrigerant level with a pressure gauge to ensure it is within specifications.
5
Test the AC relay and fuse for continuity and proper operation.
6
Inspect the cabin air filter for clogs or blockages that could restrict airflow.

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

•OBD-II scanner
•Refrigerant pressure gauge
•Multimeter
•Socket set
•UV leak detection kit
•Torque wrench

Parts Required

•AC refrigerant (R-1234yf or R-134a)
•AC compressor (if needed)
•AC relay and fuse (if needed)
•Cabin air filter

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Diagnostic Steps

1
Check the AC system for visible leaks, particularly around the condenser and compressor.
2
Use an OBD-II scanner to check for any error codes related to the AC system.
3
Inspect the AC compressor clutch to determine if it is engaging when the AC is turned on.
4
Measure the refrigerant level with a pressure gauge to ensure it is within specifications.
5
Test the AC relay and fuse for continuity and proper operation.
6
Inspect the cabin air filter for clogs or blockages that could restrict airflow.

Solution

1. Preparation

Gather necessary tools and parts.
Disconnect the vehicle battery to ensure safety during repairs.
Allow the engine to cool before beginning work.

2. Inspect and Repair Refrigerant Leaks

Sub-steps:
1. Locate any leaks using an ultraviolet dye and UV light if necessary.
2. If a leak is found, replace the damaged component (e.g., condenser, hoses).
3. Recharge the AC system with the correct type and amount of refrigerant (R-1234yf or R-134a as applicable).

3. Repair or Replace the AC Compressor

Sub-steps:
1. If the compressor clutch is not engaging, check for power to the compressor.
2. If no power, trace wiring back to the relay and control module.
3. If the compressor is defective, remove it by disconnecting the refrigerant lines and unbolting it from the engine.
4. Install the new compressor and reconnect all lines, ensuring proper torque specifications are followed (consult repair manual for specifics).

4. Check and Replace AC Relay/Fuse

Sub-steps:
1. Locate the AC relay and fuse in the fuse box.
2. Test the relay with a multimeter for continuity.
3. Replace any faulty relays or blown fuses with OEM parts.

5. Replace Cabin Air Filter

Sub-steps:
1. Locate the cabin air filter housing (usually behind the glove box).
2. Remove the old filter and clean the housing.
3. Install a new cabin air filter, ensuring it is oriented correctly.