P1116
ChryslerEngine Coolant Temperature (ECT) sensor out of range or failing self-test.
Medium SeverityCode P1116 indicates that the Engine Coolant Temperature (ECT) sensor is reporting values outside its expected operating range or failing a self-test. This can lead to incorrect fuel mixture, affecting engine performance and fuel efficiency.
⚠️ Before You Begin (Safety First)
Always allow the engine to cool completely before working on the cooling system to prevent burns. Disconnect the battery before performing any electrical work. Be cautious of hot engine components and fluids.
Common Symptoms
- Check Engine Light illuminated
- Engine running rich or lean
- Poor fuel economy
- Engine performance issues (hesitation, rough idle)
- Erratic temperature gauge readings
- Engine slow to warm up or overheating
Common Causes
- Faulty Engine Coolant Temperature (ECT) sensor
- Wiring harness open or short circuit affecting the ECT sensor
- Poor electrical connection at the ECT sensor
- Low engine coolant level
- Faulty thermostat (less common, but can impact coolant temp readings)
- Problem with the Powertrain Control Module (PCM) (rare)
Frequently reported on: Chrysler 300 (2005-2010), Dodge Charger (2006-2010), Jeep Grand Cherokee (2005-2010), Dodge Ram 1500 (2006-2011)
Diagnostic Steps
- Locate the Engine Coolant Temperature (ECT) sensor. Consult your vehicle's service manual for its exact location, often near the thermostat housing or cylinder head.
- Inspect the sensor's electrical connector and wiring for any signs of damage, corrosion, or loose connections. Repair as necessary.
- Check the engine coolant level and condition. Ensure it is at the proper level and free of contaminants.
- Carefully disconnect the electrical connector from the ECT sensor.
- Using a wrench or sensor socket, remove the old ECT sensor. Be prepared for some coolant to leak out; have a drain pan ready.
- Install the new ECT sensor, ensuring the O-ring is properly seated and it is tightened to manufacturer specifications.
- Reconnect the electrical connector.
- Top off the coolant system if needed and bleed any air from the system according to your vehicle's manual.
- Clear the P1116 code using an OBD-II scanner and test drive the vehicle to confirm the repair.
👨🔧 When to Call a Professional
If replacing the Engine Coolant Temperature sensor does not resolve the P1116 code, or if you suspect wiring damage or an issue with the powertrain control module (PCM), it is best to consult a professional mechanic for further diagnosis.
Commonly Asked Questions
What does P1116 mean for my Chrysler vehicle?
P1116 indicates a problem with your Engine Coolant Temperature (ECT) sensor circuit, meaning the sensor is reporting out-of-range values or failing its internal checks.
Can I drive with a P1116 code?
While you might be able to drive, it's not recommended for long. The engine's computer might be getting incorrect temperature readings, leading to poor fuel economy, emissions, or even potential overheating or damage if the engine runs too lean or rich.
Is replacing the ECT sensor difficult?
For most vehicles, replacing the ECT sensor is a relatively straightforward DIY task, often rated as easy. It involves locating the sensor, disconnecting wiring, unscrewing the old sensor, and installing a new one.
Do I need to drain all the coolant to replace the ECT sensor?
Not usually. You might lose a small amount of coolant when removing the sensor, so have a drain pan ready and be prepared to top off the system afterward.
What if replacing the ECT sensor doesn't fix P1116?
If the new sensor doesn't resolve the code, you should inspect the wiring harness for damage or corrosion, check the electrical connectors, and ensure the coolant level is correct. If these are fine, further diagnosis by a professional may be needed to check the PCM.