2021 - 2025 Chevrolet Trailblazer Theft Control Module (OEM)

What to Look For When Buying

• Make sure the part is for your car's year, make, and model.
• Check the part's condition (if buying used).
• Read reviews from other buyers.
• Buy from a trusted seller.

Quality Indicators

What's Included

• The theft control module itself.
• Sometimes, instructions or wiring diagrams.
• Check with the seller to confirm what's included.

Difficulty Level and Estimated Time

Replacing a theft control module can be tricky. It's generally considered a medium to high difficulty job.

• Difficulty: 6/10
• Estimated Time: 1-3 hours

Special Tools Needed

• Basic hand tools (sockets, wrenches, screwdrivers)
• Multimeter (for testing electrical connections)
• Scan tool (to clear error codes and reprogram the system)

Critical Steps and Tips

1. Disconnect the battery: This is very important for safety.
2. Locate the module: It's usually under the dashboard or in the center console.
3. Disconnect the wiring harness: Be careful not to damage the connectors.
4. Install the new module: Connect the wiring harness and secure the module.
5. Reconnect the battery:
6. Reprogram the system: You may need a scan tool to reprogram the new module to your car.

DIY or Professional Installation?

Professional installation is recommended. Reprogramming the module often requires specialized equipment and knowledge. If you're not comfortable with electrical work or don't have the right tools, it's best to leave it to a professional.

Used OEM

Used OEM theft control modules are original factory parts that have been removed from other vehicles.

• Pros:
• Lower price than new parts.
• Genuine factory quality.
• Tested and inspected to ensure they work.
• Cons:
• May have some wear and tear.
• Limited warranty (if any).

New Aftermarket

New aftermarket theft control modules are made by third-party companies.

• Pros:
• Brand new condition.
• Can be cheaper than OEM.
• Often come with a warranty.
• Cons:
• Quality can vary by brand.
• May not be as reliable as OEM.

Parts Commonly Replaced or Checked

• Key Fob: If the key fob isn't working, it could be the problem instead of the theft control module.
• Battery: A weak battery can cause security system problems.
• Wiring Harness: Damaged wires can cause the theft control module to malfunction.
• Ignition Switch: A faulty ignition switch can interfere with the security system.

Preventing Repeat Failures

Replacing related parts at the same time can help prevent future problems. For example, if a damaged wiring harness caused the theft control module to fail, replacing the harness will prevent the new module from being damaged as well.

How Long This Part Normally Lasts

A theft control module can last for many years, often 8-12 years or more.

Factors That Affect Longevity

• Climate: Extreme temperatures and humidity can shorten the lifespan.
• Water Damage: Leaks or floods can damage the module.
• Electrical Problems: Surges or shorts can cause the module to fail.
• Quality of the Part: OEM parts tend to last longer than aftermarket parts.

Budget vs Mid-Range vs Premium Options

• Used OEM: $75 - $200
• New Aftermarket: $100 - $300
• Labor Cost: $100 - $300 (if professional installation is needed)

Total Job Cost Estimates

• DIY (Used OEM): $75 - $200 (plus cost of scan tool if needed)
• Professional Installation (Used OEM): $175 - $500
• Professional Installation (New Aftermarket): $200 - $600

Known Issues

Some vehicles in this range (2018-2025 Buick, Cadillac, Chevrolet, & GMC) have reported issues with the theft control module causing false alarms or preventing the vehicle from starting. These issues are sometimes related to software glitches or faulty wiring.

TSBs and Common Complaints

Check online forums and databases for any Technical Service Bulletins (TSBs) related to the theft control module on your specific vehicle. These bulletins may provide information about common problems and solutions.

How to Confirm Proper Operation

• Start the car to make sure it starts normally.
• Test the remote key fob to make sure it locks and unlocks the doors.
• Check the security light on the dashboard. It should turn off after the car starts.
• Let the car sit for a while and make sure the alarm doesn't go off for no reason.

What to Look/Listen For

• Make sure the car starts smoothly.
• Listen for any unusual noises from the security system.
• Watch for any warning lights on the dashboard.

Q: Will this part need to be programmed?
A: Yes, most likely. The new theft control module will need to be programmed to your car's computer system. This usually requires a special scan tool.

Q: Can I install this part myself?
A: You can, but it's not recommended unless you have experience with electrical work and have the right tools. Professional installation is usually the best option.

Q: How do I know if this part is the problem?
A: The best way to know for sure is to have a mechanic diagnose the system. They can use special tools to read error codes and test the theft control module.

Q: What if the part doesn't fix the problem?
A: There could be other issues with your car's security system. A mechanic can help you diagnose the problem and find the right solution.

Q: Do used parts come with a warranty?
A: It depends on the seller. Some sellers offer a limited warranty on used parts, but others don't. Be sure to check before you buy.

OEM Part Numbers:

• GM: 13518836, 13518840, 13518841, 13558722

Fits Years: 2021 2022 2023 2024 2025