2000 Saturn LS Coolant Temperature Sensor: A Vehicle-Specific Guide
If your 2000 Saturn LS has a rough idle, poor fuel economy, or an erratic temperature gauge, the coolant temperature sensor is a likely and inexpensive culprit.
- The original resin-tipped sensor is a known failure point; ensure your replacement has a more durable brass tip.
- Symptoms like poor MPG, rough idle, and an erratic temp gauge strongly point to this sensor.
- This is a very easy and inexpensive DIY repair that can be done in under 30 minutes with basic tools.
- Always inspect the electrical connector for corrosion when replacing the sensor; it may also need replacement.
A Known Issue for the 2000 Saturn LS
Many Saturn vehicles from this era, including the 2000 LS, were originally equipped with a coolant temperature sensor that has a plastic or resin tip. These resin-tipped sensors are known to become brittle and crack over time. A cracked sensor can lead to incorrect temperature readings and may even leak coolant into the electrical connector, causing green corrosion and further electrical problems. When replacing the sensor, it is highly recommended to use a new part with a more durable brass tip to prevent this common failure.
Symptoms of a Failing Sensor
When the ECT sensor fails, it sends incorrect data to the engine's computer, which can cause a variety of noticeable problems. Here’s what to look for:
- Check Engine Light: This is the most common symptom. The computer will store diagnostic trouble codes, often P0117 (low voltage) or P0118 (high voltage), which point directly to a sensor circuit problem.
- Poor Engine Performance: You may experience a rough or high idle, difficulty starting, and reduced power. The engine may feel sluggish during acceleration.
- Reduced Fuel Economy: If the sensor incorrectly tells the computer the engine is always cold, the computer will inject more fuel than necessary, causing poor gas mileage.
- Black Smoke from Exhaust: A rich fuel mixture caused by a bad sensor can result in unburned fuel burning in the exhaust, creating black smoke.
- Erratic Temperature Gauge: The gauge on your dashboard might not move, or it could jump between cold and hot unexpectedly.
- Cooling Fan Issues: The radiator fans might run constantly, even when the engine is cold, or they might not turn on when the engine is overheating.
Check the Connector
When you replace the sensor, always inspect the electrical connector. The original resin-tipped sensors were prone to leaking coolant into the connector, causing corrosion. If you see any green crust or damage, the connector pigtail should be replaced along with the sensor to ensure a reliable repair.
Choosing the Right Aftermarket Part
For a vehicle like the 2000 Saturn LS, the distinction between OEM and aftermarket sensors is less critical than for newer, more complex vehicles, especially for a simple sensor like the ECT. The key is to choose a quality replacement part that meets or exceeds original specifications. Since many original sensors had a failure-prone resin tip, a modern aftermarket replacement with a brass tip is actually an upgrade. "Replacement" branded parts are designed to be a cost-effective solution that provides reliable, standard performance. Given the low cost and the upgrade from the original design, a new aftermarket sensor is a practical and smart choice for this repair.
Cost to Replace a 2000 Saturn LS Coolant Temperature Sensor
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Sensor | $20.68 |
| Shop Labor | $60 - $120 |
DIY Savings
Replacing the ECT sensor is a simple and quick job that most DIYers can complete in under an hour with basic tools. Doing it yourself can save you over $100 in labor costs. The sensor is easily accessible on both the 4-cylinder and V6 engines.
Frequently Asked Questions
Where is the coolant temperature sensor located on a 2000 Saturn LS?
The location depends on your engine. For the 2.2L 4-Cylinder, the sensor is near where the upper radiator hose connects to the engine, just below the EGR valve. For the 3.0L V6, it is located in the lower coolant passage of the cylinder head that is closer to the firewall.
Do I need to drain the coolant to replace the sensor?
No, you don't need to drain the entire cooling system. If you have the new sensor ready to go, you can quickly swap them, and only a small amount of coolant will be lost. Placing a rag underneath will help catch any spillage.
Are there any recalls for this sensor?
No. A search of the National Highway Traffic Safety Administration (NHTSA) database shows no recalls or technical service bulletins (TSBs) specifically for the coolant temperature sensor on the 2000 Saturn LS.
My car has two temperature sensors. Which one is this?
Some older Saturns had two sensors, but the 2000 model year should have a single, two-wire sensor that provides information to both the engine computer and the dashboard gauge. This is the one that affects engine performance and triggers the Check Engine Light.
Technical Specifications
OEM Part Numbers: 2111043 500382599
2-pin blade-style connector.
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.
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