how to fix the AC not blowing cold air in 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

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 symptoms, diagnostic steps, 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 systems.
•Allow the engine to cool before opening any components.

Symptoms

•AC system is blowing warm air
•Unusual noises when the AC is turned on
•AC compressor not engaging
•Visible refrigerant leaks
•Poor airflow from AC vents

Diagnostic Steps

1
Check the AC controls to ensure they are set correctly to the coldest setting.
2
Inspect the AC compressor for signs of damage or wear.
3
Use an OBD-II scanner to check for any related error codes.
4
Check the refrigerant level using a manifold gauge set.
5
Inspect AC fuses and relays to ensure they are functioning properly.
6
Look for any visible leaks in the AC system hoses and connections.

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

•Manifold gauge set
•Refrigerant
•Socket set
•Screwdrivers
•Multimeter
•Safety goggles

Parts Required

•AC compressor (if faulty)
•AC refrigerant
•Fuses (if blown)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Check the AC controls to ensure they are set correctly to the coldest setting.
2
Inspect the AC compressor for signs of damage or wear.
3
Use an OBD-II scanner to check for any related error codes.
4
Check the refrigerant level using a manifold gauge set.
5
Inspect AC fuses and relays to ensure they are functioning properly.
6
Look for any visible leaks in the AC system hoses and connections.

Solution

1. Preparation

Gather tools: manifold gauge set, refrigerant, socket set, screwdrivers, and safety goggles.
Ensure the vehicle is parked on a flat surface and the engine is off.
Disconnect the battery to ensure safety while working on electrical components.

2. Check and Recharge Refrigerant

Sub-step 1: Connect the manifold gauge set to the low and high-pressure service ports on the AC system.
Sub-step 2: Start the engine and turn the AC to the maximum setting; observe the pressure readings on the gauges.
Sub-step 3: If the refrigerant level is low, add the appropriate type of refrigerant (typically R-134a) until the correct pressure is reached (check the vehicle manual for specifications).
Tools Required: Manifold gauge set, refrigerant.

3. Inspect and Replace AC Compressor (if necessary)

Sub-step 1: If the compressor is not engaging, visually inspect the wiring and the clutch for damage.
Sub-step 2: If the compressor is faulty, remove the serpentine belt by loosening the tensioner.
Sub-step 3: Disconnect the AC lines and electrical connectors from the old compressor.
Sub-step 4: Install the new compressor, reconnect the AC lines and electrical connectors, and replace the serpentine belt.
Tools Required: Socket set, screwdrivers, AC compressor.

4. Check and Replace AC Fuses and Relays

Sub-step 1: Locate the fuse box under the dashboard or hood and check the AC fuses with a multimeter for continuity.
Sub-step 2: Replace any blown fuses with the same amperage rating.
Sub-step 3: Test the relays by swapping them with a similar relay to determine if they are operational.
Tools Required: Multimeter.