2021 - 2023 Chevrolet Trailblazer Engine Control Unit (ECU) (OEM)
✓IN STOCK
$78.95
ℹ️ Product Notes
This is a used part. It is an Engine Control Module (ECU). It fits vehicles with 1.3L, 2.0L, or 2.7L engines, and the classic (Limited) style. IMPORTANT: This module might need to be reprogrammed by a mechanic before it will work in your vehicle.
Requires professional programming to your VIN before it will work. Fits 1.3L, 2.0L, or 2.7L Turbo engines only. Match your original part number exactly.
Original Part #(s): 12689093, 12697793, 12703423, 12706635, 12726508
✓ Quality-Verified: Every used OEM part we sell has been professionally inspected and tested to ensure it meets our quality standards. While it may show some cosmetic wear from previous use, it's fully functional and ready to install.
✓ Original Equipment: This is a genuine OEM (Original Equipment Manufacturer) part - the exact same part that came with your vehicle from the factory. It's designed specifically for your make and model, ensuring perfect fitment and performance.
✓ Works Like New: Despite some visual wear, this part will perform just as well as a brand new one. The internal components and functionality are intact, giving you the same reliability you'd expect from OEM quality.
✓ Significant Savings: Save 50-80% compared to buying new! Used OEM parts offer exceptional value - you get factory quality at a fraction of the cost. It's the smart choice for budget-conscious vehicle owners who won't compromise on quality.
✓ Risk-Free Purchase: We stand behind our used parts with a generous 6-month warranty, 30-day returns, and 100% money-back guarantee. If it doesn't work out for any reason, simply return it for a full refund. You have nothing to lose!
🛡️ 30-Day Returns + 6-Month Warranty - Buy with Confidence!
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Vehicle Fitment Guide
This part fits the following vehicles:
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Chevrolet
Trailblazer2021-2023(tapclick to expand)(tapclick to hide)
⚠️ Important: Please verify your vehicle's year, make, model, and specifications before ordering. If you're unsure about fitment, contact our customer service team for assistance.
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Shipping & Handling
Standard shipping: 3-7 business days via UPS Ground
Parts are carefully packaged to prevent damage during transit
Returns (30 Days)
We accept returns within 30 days of delivery for this part.
Defective parts: We will replace the part or issue a refund at our discretion
Electronic parts: Must be returned with the sealed inspection bag unopened. The clear bag allows full visual inspection before opening. Once opened, electronic parts can only be exchanged for a replacement if defective — no refunds
Programming: "Needs to be programmed to my vehicle" is not a valid return reason. Many modules require dealer programming — we're happy to help connect you with resources if your dealer says it's not programmable
Return shipping: We cover return shipping as part of our 100% money-back guarantee
Parts must be returned in original packaging and unmodified condition
Poorly packaged returns that arrive damaged will not be credited
6-Month Warranty
All used parts include a 6-month warranty from the date of purchase.
If your part fails within 6 months, we will send a replacement
Refunds are only issued if we cannot provide a suitable replacement
Warranty covers defects — not installation errors, misuse, or damage after installation
Note: Warranty is for replacement, not refund. A part failing on day 80? We'll replace it. But the return window for refunds is 30 days.
Damaged in Shipping?
If your part arrives damaged:
Stop immediately — do not install the part
Keep all original packaging and boxes
Take clear photos of the damage and packaging
Contact us within 48 hours of delivery
We will handle the carrier claim. You are not responsible for shipping damage — we just need your help documenting it.
Order Cancellation
Orders can be cancelled before shipment for a full refund. Once shipped, cancellations follow our return policy.
Symptoms & Diagnosis
Warning Signs of a Failing Engine Control Unit (ECU)
Engine misfires or runs rough
Check Engine Light is on
Engine stalls or won't start
Poor fuel economy
Transmission shifting problems
Failed emissions test
Testing the ECU vs. Other Components
Check the basics: Make sure the battery is good, and all connections are clean and tight.
Scan for codes: Use an OBD2 scanner to read the trouble codes. This will give you clues about what's wrong.
Inspect wiring: Look for damaged or corroded wires and connectors going to the ECU and related sensors.
Test sensors: Use a multimeter to test the sensors that send information to the ECU, such as the mass airflow sensor and oxygen sensors.
Isolate the ECU: If other tests don't reveal the problem, the ECU might be the issue. A professional can perform more advanced tests.
Common Causes of ECU Failure
Water damage or corrosion
Overheating
Electrical surges
Vibration
Age
Buyer's Checklist
What to Look for When Buying
Correct part: Make sure the part is the right one for your vehicle's year, make, and model.
Warranty: Look for a warranty to protect your investment.
Seller reputation: Buy from a reputable seller with good reviews.
Quality Indicators
Feature
Used OEM
New Aftermarket
Origin
Original equipment from the manufacturer
Made by a third-party manufacturer
Testing
Typically tested and inspected
Brand new, but may have varying quality control
Price
Generally lower than new
Can be lower or similar to used OEM
Reliability
Can be very reliable when tested
Reliability can vary by brand
What's Included
The Engine Control Unit (ECU) itself.
Sometimes, instructions or a basic wiring diagram.
Installation Overview
Difficulty Level and Estimated Time
Difficulty: Medium
Estimated Time: 1-3 hours
Special Tools Needed
Basic hand tools (sockets, wrenches, screwdrivers)
OBD2 scanner
Multimeter (optional)
Critical Steps and Tips
Disconnect the battery: This is very important to prevent electrical damage.
Locate the ECU: It's usually under the dashboard or in the engine compartment.
Disconnect the wiring harness: Be careful not to damage the connectors.
Install the new ECU: Connect the wiring harness and secure the ECU.
Reconnect the battery:
Program the ECU: Some ECUs need to be programmed to your vehicle. This usually requires a scan tool.
DIY or Professional Installation?
If you're comfortable working on cars and have some experience, you might be able to do it yourself.
If you're not sure, it's best to have a professional install it. Programming the ECU often requires specialized equipment.
Buying Options
Compare: Used OEM, New Aftermarket
Feature
Used OEM
New Aftermarket
Origin
Original equipment from the manufacturer
Made by a third-party manufacturer
Testing
Typically tested and inspected
Brand new, but may have varying quality control
Price
Generally lower than new
Can be lower or similar to used OEM
Reliability
Can be very reliable when tested
Reliability can vary by brand
Used OEM
Best value for your money.
Genuine factory parts.
Tested and inspected to ensure they work.
Significantly lower prices than new parts.
New Aftermarket
Brand new parts.
Made by third-party manufacturers.
Built to meet or exceed OE specifications.
Related Parts
Parts Commonly Replaced or Checked
Mass Airflow (MAF) Sensor
Oxygen (O2) Sensors
Crankshaft Position Sensor
Camshaft Position Sensor
Wiring Harness
Why Replace Related Parts?
Replacing related parts can prevent repeat failures.
A faulty sensor can damage the ECU.
Old wiring can cause problems with the new ECU.
Typical Lifespan
How Long This Part Normally Lasts
An ECU can last for the life of the vehicle.
Typically 10-15 years or more.
Factors That Affect Longevity
Heat
Vibration
Moisture
Electrical surges
Quality of related sensors
Price Ranges
Budget vs. Mid-Range vs. Premium Options
Used OEM: $100 - $300
New Aftermarket: $150 - $400
Labor Cost Considerations
Labor costs can range from $100 to $300, depending on the shop and the complexity of the job.
Total Job Cost Estimates
DIY: $100 - $400 (parts only)
Professional Installation: $200 - $700 (parts and labor)
Vehicle-Specific Notes
Some vehicles are known to have issues with ECU grounding. Make sure the ECU is properly grounded.
Check for any Technical Service Bulletins (TSBs) related to the ECU on your specific vehicle.
Some vehicles require the ECU to be programmed to match the VIN.
Verification After Install
How to Confirm Proper Operation
Start the engine and let it idle.
Check for any warning lights on the dashboard.
Take the vehicle for a test drive.
What to Look/Listen for
Smooth engine operation.
Proper shifting.
No unusual noises.
Normal fuel economy.
No Check Engine Light.
FAQ
Q: Will this ECU need to be programmed? A: Some ECUs need to be programmed to your vehicle's VIN. Check with a professional or the seller to see if programming is required.
Q: What happens if I install the wrong ECU? A: The engine may not start, or it may run poorly. It could also damage the ECU or other components.
Q: How do I know if the ECU is really the problem? A: Have a professional diagnose the problem to be sure. It's important to rule out other possible causes first.
Q: What kind of warranty comes with a used OEM ECU? A: Warranty coverage varies by seller. Check the seller's warranty policy before you buy.
Q: Can I return the ECU if it doesn't fix my problem? A: Check the seller's return policy before you buy. Make sure you understand the terms and conditions.
