Engine Coolant Temperature Sensor Guide for the 2012-2015 Ram C/V
Is your Ram C/V's temperature gauge acting up or is your fuel economy dropping? Your coolant sensor might be the culprit.
- A failing ECT sensor on your Ram C/V can cause a check engine light, poor fuel economy, and an incorrect temperature gauge reading.
- The 3.6L Pentastar engine can be sensitive to sensor accuracy; using an OEM Mopar part (5149077AB) is highly recommended to avoid issues.
- This is a simple, low-cost DIY repair that takes less than an hour with basic tools.
- The most common trouble code associated with this issue is P0128, which can be caused by either the sensor or a bad thermostat.
Is Your Ram C/V's Coolant Sensor Failing?
A bad Engine Coolant Temperature (ECT) sensor can cause more than just a faulty reading on your dash. Because your van's computer relies on this sensor for critical data, a failure can lead to noticeable performance problems. Ignoring these signs can lead to poor fuel economy, failed emissions tests, and potentially more serious engine issues down the road.
Key Symptoms of a Bad ECT Sensor:
- Check Engine Light: This is often the first sign. A scan tool will likely show fault codes like P0117 (Circuit Low), P0118 (Circuit High), or the very common P0128 (Coolant Temperature Below Thermostat Regulating Temperature).
- Poor Fuel Economy: If the sensor incorrectly tells the computer the engine is cold, the system will inject extra fuel, hurting your gas mileage.
- Inaccurate Temperature Gauge: The gauge on your dashboard might stay on cold, jump to hot unexpectedly, or provide erratic readings.
- Cooling Fans Run Constantly or Not at All: As a fail-safe, the computer may run the cooling fans at full speed if it gets a bad signal. Conversely, it might fail to turn them on, creating an overheating risk.
- Black Smoke from Exhaust: A rich fuel mixture caused by a bad sensor reading can result in black smoke from the tailpipe.
- Hard Starting or Rough Idle: The wrong fuel mixture can make the engine difficult to start, especially when warm, and can cause a rough or unstable idle.
Choosing the Right Aftermarket Sensor for Your Ram C/V
When replacing the ECT sensor, you have a choice between the original Mopar part and several aftermarket brands. While aftermarket options can save you money, it's important to choose wisely.
Aftermarket Brand Tiers
| Tier | Brands | Quality & Value Assessment |
|---|---|---|
| Tier 1: OEM | Mopar | The original equipment sensor (part # 5149077AB) is the safest choice. The 3.6L Pentastar engine can be sensitive to sensor voltage, and using the OEM part guarantees compatibility and avoids hard-to-diagnose issues that sometimes occur with aftermarket alternatives. |
| Tier 2: Premium Aftermarket | Delphi, Standard Ignition (SMP), Beck Arnley | These brands have a strong reputation for producing quality components that meet or exceed OE specifications. They are a reliable, cost-effective alternative to Mopar. For many owners, these brands provide a good balance of price and performance. |
| Tier 3: Economy Aftermarket | Global Parts, Holstein, Walker Products, others | While these brands offer the lowest price, their quality can be inconsistent. Given the low cost of even premium sensors and the engine's sensitivity, it's often worth spending a few extra dollars for a more trusted brand to avoid replacing the part twice. |
Pro Tip: Many experienced mechanics and owners strongly recommend using the OEM Mopar sensor for the 3.6L Pentastar engine. The extra cost is often considered cheap insurance against the frustration of a new aftermarket sensor that doesn't solve the problem completely.
How Much Does a New Coolant Sensor Cost for a 2012-2015 Ram C/V?
The cost will depend on the brand you choose and whether you do the work yourself or take it to a professional mechanic.
Estimated Replacement Costs
| Item | Estimated Cost |
|---|---|
| New OEM (Mopar) Part | $47 - $70 |
| New Aftermarket Part | $19 - $75 |
| Shop Labor | $77 - $113 |
| Total Professional Replacement | $124 - $183 (Aftermarket) / $150 - $210 (OEM) |
Frequently Asked Questions (FAQ)
Where is the ECT sensor located on the 2012-2015 Ram C/V?
The ECT sensor on the 3.6L Pentastar engine is located on the front cylinder head (Bank 2), which is on the passenger side of the engine bay. It is a brass-colored sensor threaded into the head, near the thermostat housing. 🎬 Watch a mechanic replace the sensor on a 3.6L engine. It is relatively easy to access after removing the plastic engine cover.
Can I replace the coolant temperature sensor myself?
Yes, this is a very DIY-friendly job for someone with basic tools. The difficulty is low and it should take less than an hour. You will need to remove the engine cover, unclip the electrical connector, and use a 19mm (or 3/4 inch) deep socket to unscrew the old sensor and install the new one. Always perform this work on a cold engine.
🎬 Watch this step-by-step guide to replacing the sensor yourself.Do I need to drain the coolant to replace the sensor?
You do not need to drain the entire cooling system. A small amount of coolant will leak out when you remove the old sensor. If you have the new sensor ready to go, you can swap it in quickly to minimize coolant loss. Just be prepared with a rag to clean up any spillage.
My van has a P0128 code. Is it the sensor or the thermostat?
The P0128 code means the engine isn't warming up as quickly as the computer expects. This is most often caused by a thermostat that is stuck open or a faulty ECT sensor giving an incorrect reading. Since the sensor is generally cheaper and easier to replace than the thermostat, many people start by replacing the sensor. If the code returns, the thermostat is the next likely culprit.
🎬 See the top 3 causes for the P0128 engine code.Helpful Videos
Technical Specifications
OEM Part Numbers: 5149077AB 05149077AB 5149096AB
The sensor is typically located on the passenger side cylinder head, near the thermostat housing. It is a 2-pin brass sensor that requires a 19mm or 3/4" deep socket for removal and installation.
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.
- Ram C/V:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Ram C/V's Coolant Sensor Failing?
- Key Symptoms of a Bad ECT Sensor:
- Choosing the Right Aftermarket Sensor for Your Ram C/V
- Aftermarket Brand Tiers
- How Much Does a New Coolant Sensor Cost for a 2012-2015 Ram C/V?
- Estimated Replacement Costs
- Frequently Asked Questions (FAQ)
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