Guide to the Coolant Temperature Sensor for 2001-2006 Chevrolet Silverado 1500 HD
This small sensor on your 6.0L V8 can cause big problems, from a check engine light to poor fuel economy.
- A bad coolant temp sensor on your Silverado 1500 HD will often trigger a Check Engine Light with codes P0117 or P0118.
- Replacement is an easy DIY job located on the driver's side cylinder head, requiring a 19mm deep socket.
- Before replacing the sensor, always check its wiring harness for damage, as it can rub against the #1 spark plug wire and cause similar symptoms.
- If your truck has a P0128 code, the problem is more likely a stuck-open thermostat, not the sensor itself.
Is Your Silverado 1500 HD's Coolant Temp Sensor Failing?
A faulty Engine Coolant Temperature (ECT) sensor can cause a range of confusing problems for your truck. Because this one sensor provides data to so many different systems, its failure can mimic other, more serious engine issues. Understanding the symptoms is the first step to a correct diagnosis and a quick repair.
Pro Tip: Check the Wiring First
Before you replace the sensor, take a moment to inspect the wiring and connector. On the 6.0L V8 engine, the sensor's wire can sometimes rub against the #1 spark plug wire. This can cause damage or electrical interference that looks just like a sensor failure. Make sure the connector is clean, not corroded, and fits tightly.
Symptoms of a Bad Coolant Temperature Sensor
- Check Engine Light: This is usually the first sign. Your truck's computer will store a fault code, most often P0117 (sensor circuit low voltage) or P0118 (sensor circuit high voltage). 🎬 See a detailed diagnosis and explanation of P0117 and P0118 codes.
- Erratic Temperature Gauge: The gauge on your dashboard might stay on cold, swing back and forth wildly, or drop to its lowest reading unexpectedly. When this happens, the truck's computer may turn the cooling fans on high as a safety measure.
- Poor Fuel Economy: If the sensor incorrectly tells the computer the engine is cold, the computer will enrich the fuel mixture, causing the truck to use more gas than necessary.
- Hard Starting or Rough Idle: A bad sensor can send the wrong temperature reading, leading to an incorrect fuel mixture that makes the engine hard to start (especially when warm) or idle roughly. 🎬 Watch a breakdown of common symptoms caused by a failing sensor.
Choosing the Right Aftermarket Sensor
When it comes to sensors, the debate between OEM (Original Equipment Manufacturer) and aftermarket is common. For the Silverado, the OEM brand is ACDelco. However, for a simple and common part like a coolant temperature sensor, a quality aftermarket brand provides a reliable and cost-effective solution. Brands like Delphi are often the original supplier to GM, meaning you get an OEM-quality part without the dealer price tag. A standard "Replacement" brand sensor is a budget-friendly choice that is typically sufficient for this type of part, which is not complex electronically.
Cost to Replace a Silverado 1500 HD Coolant Temp Sensor
| Part/Service | Estimated Cost |
|---|---|
| New OEM (ACDelco) Sensor | $30 - $50 |
| New Aftermarket Sensor | $20.68 |
| Shop Labor Cost | $75 - $150 |
Frequently Asked Questions (FAQ)
Where is the coolant temperature sensor located on the 2001-2006 Silverado 1500 HD?
The sensor is located on the driver's side of the 6.0L V8 engine. It is screwed into the cylinder head, near the front of the engine, just below the thermostat housing.
Is this a difficult repair to do myself?
No, this is a great job for a beginner. It can be done in under an hour with basic tools. You will need a 19mm (or 3/4 inch) deep socket and a ratchet. Let the engine cool completely, disconnect the electrical plug, and then quickly swap the old sensor for the new one to minimize coolant loss.
Do I need to drain all the coolant to replace the sensor?
No, you do not need to drain the entire system. A small amount of coolant will spill out when you remove the old sensor. Have the new sensor ready to install quickly to keep the mess to a minimum, and place a drain pan underneath to catch what spills. It's a good idea to have some extra coolant on hand to top off the system afterward.
Are there any recalls for this part?
No, as of early 2026, there are no recalls from the NHTSA for the engine coolant temperature sensor on the 2001-2006 Chevrolet Silverado 1500 HD.
My truck has a P0128 code. Is that the sensor?
A P0128 code means the engine coolant temperature is below the thermostat's regulating temperature. While a bad sensor can sometimes cause this, it is almost always caused by a thermostat that is stuck open. If you have a P0128 code, you should plan on replacing your thermostat.
Helpful Videos
Technical Specifications
OEM Part Numbers: 213-4396 213-928
Location: Driver's side cylinder head. Socket Size: 19mm (or 3/4 inch) deep socket. Torque Spec: ~15-17 ft-lbs.
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.
- Chevrolet Silverado 1500 HD: