GMC Sierra T1XX (2019-Present) AC not cooling how to troubleshoot

GMC Sierra T1XX (2019-Present)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

3 min read

565 words

Problem Statement

Learn how to troubleshoot and fix AC not cooling issues in GMC Sierra T1XX (2019-Present). Step-by-step diagnostic and repair instructions included.

Affected Component

HVAC

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect battery before working on electrical systems.
•Allow the AC system to depressurize before disconnecting any components.

Symptoms

•AC blows warm air instead of cold
•AC compressor does not engage
•Unusual noises coming from the AC system
•Foul odors from the AC vents
•Decreased air flow from the vents
•Check engine light illuminated

Diagnostic Steps

1
Check the AC system for any visible leaks or damage to hoses and components.
2
Use an OBD-II scanner to check for any error codes related to the AC system.
3
Verify the refrigerant level using a manifold gauge set to ensure it is within specifications.
4
Inspect the AC compressor clutch for engagement when the AC is turned on.
5
Check the AC fuses and relays in the fuse box for continuity and function.
6
Test the cabin air filter for blockage and replace if necessary.

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
•Manifold gauge set
•Socket set
•Torque wrench
•Refrigerant

Parts Required

•AC compressor
•Cabin air filter
•Refrigerant

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Diagnostic Steps

1
Check the AC system for any visible leaks or damage to hoses and components.
2
Use an OBD-II scanner to check for any error codes related to the AC system.
3
Verify the refrigerant level using a manifold gauge set to ensure it is within specifications.
4
Inspect the AC compressor clutch for engagement when the AC is turned on.
5
Check the AC fuses and relays in the fuse box for continuity and function.
6
Test the cabin air filter for blockage and replace if necessary.

Solution

1. Preparation

Gather all necessary tools and parts.
Disconnect the battery to ensure safety.

2. Recharge Refrigerant

Tools Needed: Manifold gauge set, refrigerant (R-134a or R-1234yf as specified).
Steps:
1. Connect the low-pressure side of the manifold gauge to the AC service port.
2. Open the valve of the refrigerant canister and allow refrigerant to flow into the system until the appropriate pressure is reached (refer to manufacturer specifications).
3. Disconnect the manifold gauge and recap the service port.

3. Repair or Replace AC Compressor

Tools Needed: Socket set, torque wrench, AC compressor replacement.
Steps:
1. Remove the serpentine belt by loosening the tensioner.
2. Disconnect electrical connectors and refrigerant lines from the AC compressor.
3. Unbolt the AC compressor from its mounting bracket and remove it.
4. Install the new AC compressor, ensuring proper alignment and connection.
5. Reattach the refrigerant lines and electrical connectors.
6. Reinstall the serpentine belt, ensuring proper routing and tension.

4. Replace Cabin Air Filter

Tools Needed: None specifically; may require a flathead screwdriver.
Steps:
1. Locate the cabin air filter access panel, usually found under the dashboard or behind the glove compartment.
2. Remove the access panel and take out the old filter.
3. Insert the new cabin air filter in the correct orientation.
4. Reattach the access panel securely.