Jeep Wrangler JK (2014-2019) Engine Coolant Temperature Sensor Replacement Guide
An erratic temperature gauge or check engine light on your Wrangler could be a bad coolant sensor—here's how to choose the right replacement.
- A bad coolant sensor can cause overheating, poor performance, and hard starting on your Wrangler.
- Replacement is a simple DIY job, accessed by removing the driver's side inner fender liner.
- Be careful to buy the correct part, as it's often confused with the oil temperature sensor.
- For critical sensors, using Mopar or a premium brand like Delphi or NGK is highly recommended to avoid repeat failures.
Is Your Jeep's Coolant Temp Sensor Failing?
A faulty Engine Coolant Temperature (ECT) sensor can cause more than just a check engine light. Because it provides critical data to the engine computer, a bad sensor can lead to noticeable performance issues. If the sensor sends a false 'hot' signal on a cold engine, you may experience hard starting. If it sends a false 'cold' signal, the cooling fans may not activate when needed, putting your engine at risk of overheating.
Common Ordering Mistake
Be careful when ordering this part online. Many listings incorrectly show the Oil Temperature Sensor for a coolant sensor search. The two sensors use the same electrical connector but have different thread sizes and functions. The correct Engine Coolant Temperature Sensor for the 3.6L engine is located on the driver's side cylinder head, not next to the oil filter housing. Always verify the part by comparing it to the original.
🎬 Watch: How to distinguish the coolant sensor from the oil sensor.Choosing the Right Aftermarket Sensor
While Mopar is the original equipment manufacturer, several aftermarket brands offer quality replacements. Jeeps can be particular about electronics, so choosing a reputable brand is important to avoid replacing the part twice.
Brand Quality Tiers for Jeep Wrangler
- OEM & Premium Aftermarket: Mopar is the factory part and the safest bet for compatibility. Brands like Delphi and NGK/NTK are often original equipment suppliers to many automakers and are considered top-tier choices with excellent reliability.
- Trusted Aftermarket: Brands like Standard Ignition (SMP) and Walker Products have a solid reputation for producing reliable sensors that meet or exceed OEM specifications. They offer a good balance of quality and price.
- Jeep-Specialist Brands: Crown Automotive and Omix-Ada are well-known in the Jeep community. For a critical electronic sensor like this, community feedback often suggests sticking with Mopar or a premium brand, as sensor quality can be inconsistent.
- Value Brands: Dorman and other value-focused brands are widely available. While some Dorman parts are well-regarded, for sensitive electronics on a Jeep, many owners recommend spending a bit more for an OEM or premium aftermarket sensor to ensure long-term reliability.
Pro Tip: Check the Thermostat First
The trouble code P0128 (Coolant Temperature Below Regulating Temperature) can be triggered by a bad sensor OR a thermostat that is stuck open. If your Jeep is taking an unusually long time to warm up and the heater isn't blowing hot, your thermostat is the more likely culprit.
🎬 See this DIY guide for fixing a P0128 trouble code.Cost of Replacing a Jeep Wrangler Coolant Sensor
| Part Type | Estimated Cost |
|---|---|
| New OEM (Mopar) | $45 - $80 |
| New Aftermarket | $17 - $71 |
| Shop Labor | $75 - $150 |
Frequently Asked Questions
Where is the coolant temp sensor located on a 2014-2019 Wrangler?
The sensor is located on the rear of the driver's side cylinder head. The easiest way to access it is by removing the driver's side front wheel and pulling back the plastic inner fender liner.
Can I replace this sensor myself?
Yes, this is a DIY-friendly job for most home mechanics. It requires basic hand tools and accessing the sensor by removing the inner fender liner is straightforward. The job typically takes less than an hour.
🎬 Watch a complete 3.6L Pentastar coolant sensor replacement walkthrough.Do I need to drain all the coolant to replace it?
No, a full drain is not necessary. Some coolant will leak out when you remove the old sensor. To minimize loss, have the new sensor ready to install immediately after removing the old one. You will need to top off the coolant reservoir afterward with the correct type (OAT coolant for 2013+ models).
Are there any recalls for this part?
No recalls or widespread Technical Service Bulletins (TSBs) were found specifically for the engine coolant temperature sensor on the 2014-2019 Jeep Wrangler JK with the 3.6L engine.
Helpful Videos
Technical Specifications
OEM Part Numbers: 5149077AB
Location: Driver's side cylinder head, rear position. Tool size: 19mm or 3/4 inch wrench/socket.
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.
- Jeep Wrangler:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Jeep's Coolant Temp Sensor Failing?
- Common Ordering Mistake
- Choosing the Right Aftermarket Sensor
- Brand Quality Tiers for Jeep Wrangler
- Pro Tip: Check the Thermostat First
- Cost of Replacing a Jeep Wrangler Coolant Sensor
- Frequently Asked Questions
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