A Guide to the Engine Coolant Temperature Sensor for the 2016-2019 Buick Cascada
If your Cascada's 1.6L turbo engine is running rough, getting poor mileage, or showing incorrect temperature readings, the coolant sensor may be the cause.
- A failing ECT sensor can cause poor fuel economy, rough running, and overheating in your Cascada.
- No specific recalls or widespread issues have been reported for this part on this vehicle.
- Premium aftermarket brands like ACDelco, NGK, and Standard Ignition are reliable and recommended over budget options.
- Before buying, verify if your Cascada needs OEM part #12656444 or #55591002, as both may be used.
Is Your Cascada's Coolant Sensor Failing?
A faulty Engine Coolant Temperature (ECT) sensor can cause a variety of noticeable problems. Because the engine's computer relies on this sensor for so much information, a bad signal can make the car behave strangely. You might notice one or more of these issues if your sensor is on its way out.
Common Symptoms of a Bad ECT Sensor:
- Check Engine Light: This is often the first sign. The computer will detect a signal from the sensor that is out of the expected range and trigger a fault code.
- Poor Fuel Economy: If the sensor wrongly tells the computer the engine is cold, the computer will enrich the fuel mixture, causing the car to use more gas than necessary.
- Black Smoke from Exhaust: A very rich fuel mixture, caused by a bad sensor signal, can result in unburnt fuel exiting through the exhaust, appearing as black smoke.
- Engine Overheating: If the sensor fails to report that the engine is hot, it may not turn on the cooling fans when needed, leading to overheating.
- Incorrect Temperature Gauge: The gauge on your dashboard might show the engine is overheating when it's not, or it might not move from the "cold" position at all.
- Rough Idling: An incorrect fuel mixture can cause the engine to idle poorly, shake, or even stall.
No Recalls or Specific TSBs Found
As of early 2026, searches of the National Highway Traffic Safety Administration (NHTSA) database and other technical resources did not find any specific recalls or common Technical Service Bulletins (TSBs) for the engine coolant temperature sensor on the 2016-2019 Buick Cascada.
Choosing the Right Aftermarket Sensor
For a part like the ECT sensor, you don't necessarily need to buy the original OEM part from a dealer. Many aftermarket brands offer excellent quality, often at a better price. However, not all brands are created equal. Here’s a breakdown of the available options.
Tier 1: OEM & Premium Aftermarket
These brands are known for providing original equipment for many car manufacturers or for having a reputation for quality that is equivalent to OEM. They are a safe bet for reliability and fit.
- ACDelco: As General Motors' own parts brand, this is the original equipment for your Buick. Choosing ACDelco guarantees a perfect fit and original performance.
- NGK / NTK: NTK is the sensor division of NGK. They are a world-renowned manufacturer and an OE supplier for many automakers, known for high-quality sensors that meet or exceed original specifications.
- Standard Ignition (SMP): A long-standing brand with a strong reputation in the aftermarket for producing reliable sensors and other engine management components that are often considered as good as OEM.
Tier 2: Quality Aftermarket
These brands provide a good balance of quality and value. They are a solid choice for most repairs.
- Walker Products: While well-known for exhaust parts, Walker also produces a line of engine sensors and is committed to meeting OEM standards.
- Holstein: This brand markets itself as an OE-quality alternative at a lower price, claiming a very low failure rate and offering a good warranty.
Tier 3: Budget Brands
These brands compete primarily on price. While they can be a solution, some user reviews across various car communities suggest a higher risk of premature failure or fitment issues.
- URO Parts: Generally considered a budget brand. While some of their simple mechanical parts are acceptable, forum discussions often caution against using their electronic components for critical functions.
- True Tech: A value-focused brand. Less information is available on its long-term reliability compared to more established names.
Pro Tip: Verify Your Part Number
GM lists two potential OEM part numbers for this sensor on the Cascada: 12656444 and 55591002. Before ordering, it is a very good idea to visually inspect the original sensor in your car or cross-reference the number stamped on it to ensure you are buying the correct replacement.
Cost to Replace the Engine Coolant Temperature Sensor
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket | $14 - $26 |
| New OEM (Dealer) | $19 - $24 |
| Shop Labor | $75 - $150 |
| Total Professional Replacement | $90 - $175 |
Frequently Asked Questions
Where is the ECT sensor located on the 2016-2019 Buick Cascada?
On the 1.6L turbo engine, the ECT sensor is typically threaded into the thermostat housing or directly into the cylinder head on the side of the engine. You will need to remove the engine cover to see it. It's a small sensor with an electrical connector on top.
Can I replace the ECT sensor myself?
Yes, this is a relatively easy job for a DIYer with basic tools. The process involves letting the engine cool completely, disconnecting the battery, unplugging the sensor's electrical connector, and unscrewing the old sensor. Have the new sensor ready to install quickly to minimize coolant loss. Always remember to top off your coolant afterward.
Do I need to drain the coolant to replace the sensor?
You do not need to drain the entire cooling system. However, the sensor is below the coolant level, so some coolant will leak out when you remove it. Working quickly to swap the old sensor for the new one will keep the mess to a minimum. Make sure the engine is completely cold before starting to avoid burns and reduce pressure in the system.
Should I buy a cheap sensor or a premium one?
Given the sensor's critical role and the small price difference between budget and premium brands, investing in a quality part from ACDelco, NGK, or Standard is highly recommended. This reduces the risk of having to do the job again in a few months due to premature failure of a cheaper part.
Technical Specifications
OEM Part Numbers: 12656444 55591002 12636534 55563530
Typically a 2-pin, brass-bodied sensor that threads into the engine's cooling system. Comes with an O-ring for sealing.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Buick Cascada:
- 🛍️ Shop This Part
- Is Your Cascada's Coolant Sensor Failing?
- Common Symptoms of a Bad ECT Sensor:
- No Recalls or Specific TSBs Found
- Choosing the Right Aftermarket Sensor
- Tier 1: OEM & Premium Aftermarket
- Tier 2: Quality Aftermarket
- Tier 3: Budget Brands
- Pro Tip: Verify Your Part Number
- Cost to Replace the Engine Coolant Temperature Sensor
- Frequently Asked Questions
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