P0116 on 2022-2023 Jeep Cherokee: Engine Coolant Sensor Performance Causes and Fixes

What's Unique About the 2022-2023 Jeep CHEROKEE

For the Jeep Cherokee (KL generation), P0116 is frequently cited in Technical Service Bulletins (TSBs), often alongside other codes, suggesting the root cause can sometimes be overly sensitive software logic in the Powertrain Control Module (PCM). A TSB for 2022 models specifically lists P0116 as a code that may be resolved with a PCM software update. [Bulletin #18-044-26] This is a recurring issue, as similar TSBs for software updates to address P0116 were issued for earlier model years of this generation. The location of the ECT sensor and the difficulty of repair also vary significantly depending on whether the vehicle has the 2.4L I4 or 3.2L V6 engine. On the 2.4L, the sensor is part of the thermostat housing assembly, making replacement more involved. Note that the 2.4L engine was discontinued for the 2023 model year.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: The 2022-2023 models are part of the Jeep Cherokee KL generation, which began in 2014. TSBs and known issues from earlier years of this generation, particularly regarding software sensitivity and thermostat/sensor failures, are often relevant and have been noted in this article.

Symptoms You May Notice

• Check Engine Light is on.
• Temperature gauge on the dashboard behaves erratically (e.g., stays on cold, jumps to hot, or fluctuates).
• Cooling fans run constantly, even when the engine is cold, or do not turn on when needed.
• Reduced fuel economy.
• Engine may be hard to start, especially when cold.
• Heater may not blow warm air, a classic symptom of a thermostat stuck open.
• Issues with the Stop-Start system. 🎬 Watch: Common signs and symptoms of a failing ECT sensor [Bulletin #18-044-26]
• Dark exhaust smoke.

Most Likely Causes

1. Faulty Engine Coolant Temperature (ECT) Sensor 🔴 High Probability → Shop Engine Coolant Temperature Sensor Sensors can fail over time, providing incorrect resistance values to the PCM, leading to irrational readings. This is a very common failure point across many FCA vehicles.
   How to confirm: Use a scan tool to compare the ECT reading to the IAT reading on a cold engine; they should be within a few degrees of each other. Watch the live data as the engine warms up; the temperature should climb steadily. If it jumps erratically or doesn't move, the sensor is likely bad. A multimeter can also be used to test resistance; at 68°F (20°C), it should be between 2,000-3,000 ohms.
   Typical fix: Replace the ECT sensor. On the 3.2L V6, this is a standalone sensor. On the 2.4L I4 (2022 model), the sensor is often integrated into the thermostat housing and replaced as an assembly. 🎬 See how to locate and replace the 2.4L coolant sensor This requires partially draining the coolant.
   Est. part cost: $20-$60
2. Stuck Thermostat 🟡 Medium Probability → Shop Integrated Thermostat Housing Assembly If the thermostat is stuck open, the engine will warm up too slowly, causing the PCM to flag a performance issue with the temperature reading. If it's stuck closed, the engine will overheat. Modern thermostats are often designed to fail in the open position.
   How to confirm: Monitor the coolant temperature on a scan tool from a cold start. If it rises very slowly or fails to reach the normal operating temperature (typically 195-205°F), the thermostat is likely stuck open. You can also feel the upper radiator hose; it should stay cool for several minutes then get hot suddenly when the thermostat opens. If it warms up gradually, it's stuck open.
   Typical fix: Replace the thermostat and gasket. On the 2.4L engine, this is typically sold as a complete housing assembly that includes a new ECT sensor. On the 3.2L, it is also sold as a housing assembly. It's often recommended to replace the ECT sensor at the same time if it's separate.
   Est. part cost: $50-$150
3. Low Engine Coolant or Air in System 🟡 Medium Probability → Shop Engine Coolant / Antifreeze If the coolant level is low, the sensor tip can be exposed to an air pocket instead of coolant, causing erratic and irrational readings. This can happen from a leak or if the system was not properly bled after a previous repair.
   How to confirm: Visually check the coolant reservoir and radiator (when the engine is cool) to ensure the level is correct. If the system was recently serviced, it may have air trapped inside.
   Typical fix: Top off the coolant to the correct level with Mopar OAT 10-year/150,000 mile coolant. If air is suspected, the cooling system needs to be properly bled to remove all air pockets. 🎬 Watch: Step-by-step guide to servicing and bleeding the cooling system
   Est. part cost: $15-$30 for coolant
4. PCM Software Update Needed ⚪ Low Probability TSB #18-044-26 for 2022 models indicates that P0116 can be one of several codes set due to a software logic issue. [Bulletin #18-044-26, 11] Earlier models in the same generation also had TSBs for similar software sensitivity issues, sometimes triggered by using a block heater in very cold weather.
   How to confirm: A Jeep dealership or a qualified shop with access to OEM software can check your vehicle's VIN to see if this TSB or any other software updates are applicable and have not yet been performed.
   Typical fix: Update the Powertrain Control Module (PCM) software. This must be done by a dealer or a shop with the appropriate subscription and tools.
   Est. part cost: $0 under warranty, otherwise dealer labor rates apply (typically 1 hour)

Rare But Worth Checking

• Wiring or Connector Issue: Damage to the wires leading to the ECT sensor (chafing, breaks) or corrosion in the connector can cause an intermittent or out-of-range signal. A loose connector, especially if the locking tab is broken or not secured, can also be the culprit. This should be checked if a new sensor doesn't resolve the code.
• Faulty Powertrain Control Module (PCM): This is extremely rare. The PCM should only be considered as the cause after all other possibilities, including sensors, wiring, and the thermostat, have been thoroughly ruled out.

Diagnosis Steps

1. Check the coolant level in the reservoir and radiator (only when the engine is completely cool). Ensure the correct Mopar OAT coolant is being used.
2. Use an OBD-II scanner to check for any other codes that may be present. Codes like P0128, P0117, or P0118 can provide strong clues.
3. With the scanner, view live data. On a cold engine (after sitting for several hours), compare the Engine Coolant Temperature (ECT) and Intake Air Temperature (IAT) readings. They should be within 5°F (3°C) of each other.
4. Start the engine and monitor the ECT reading. It should rise steadily and smoothly as the engine warms up to its operating temperature (around 195-205°F or 90-96°C).
5. If the temperature rises very slowly, never reaches operating temperature, or drops significantly while driving at speed, suspect a thermostat that is stuck open.
6. If the temperature reading is erratic, jumps suddenly, stays at a single value (e.g., -40°F), or is clearly incorrect, suspect a faulty ECT sensor or wiring issue.
7. Visually inspect the ECT sensor's wiring and connector for any signs of damage, corrosion, or looseness. Ensure the locking tab on the connector is fully engaged.
8. If the sensor and thermostat seem to be working, but the code persists, check with a dealer for any applicable PCM software updates, like TSB #18-044-26, especially if other seemingly unrelated codes are also present.

Parts You'll Likely Need

• Engine Coolant Temperature Sensor (OEM #5149077AB) — This sensor is the most common failure point for P0116, as it directly measures the data the PCM has flagged as irrational.

Related Codes That Often Appear With This One

• P0128 — This code means 'Coolant Temperature Below Thermostat Regulating Temperature' and is very common with P0116, as both can be caused by a thermostat that is stuck open.
• P0117 — Indicates 'ECT Sensor Circuit Low', suggesting a short to ground in the circuit. P0116 is a performance code, while this points to a specific electrical fault.
• P0118 — Indicates 'ECT Sensor Circuit High', suggesting an open circuit. P0116 is a performance code, while this points to a specific electrical fault.
• P2610 — This code for 'PCM Internal Engine Off Timer Performance' is mentioned alongside P0116 in TSBs for this platform, suggesting a potential software or PCM-related issue. [Bulletin #18-093-16 REV. A]
• P05BD-00 — A TSB for 2022 models links P0116 with this 'Stop-Start Mode Switch Range/Performance' code, indicating a potential PCM software update is needed. [Bulletin #18-044-26]

Technical Service Bulletins (TSBs) & Recalls

• 18-044-26: For 2022 models, mentions P0116 as part of a group of codes that may require a PCM software update.
• 18-085-17: For older models, lists P0116 among other DTCs that may be set.
• 18-093-16 REV. A: For older models, lists P0116 with other codes like P2610, indicating potential PCM timer performance issues.
• 18-005-15 REV F: For older models, includes P0116 in a long list of potential DTCs related to software updates.
• 18-035-16 REV.A: For older models, lists P0116 with other DTCs.

Platform-Specific Known Issues

• A Technical Service Bulletin (TSB #18-044-26) for 2022 Jeep Cherokee models with the 2.4L engine notes that P0116-00 may be set along with other codes, and the recommended fix is to reprogram the PCM with the latest software. [Bulletin #18-044-26]
• The location of the ECT sensor differs by engine. On the 2.4L engine, it is on the thermostat housing on the passenger side. On the 3.2L V6, it is on the back of the driver's side cylinder head, which is more difficult to access.

Mechanic-Grade Diagnostic Values

• ECT Sensor Resistance (NTC Type) — expected: ~2000-3000 Ohms at 20°C (68°F); ~200-300 Ohms at 90°C (194°F). Failure: Infinite resistance (open circuit), zero resistance (short), or values significantly outside the expected range for a given temperature.
• ECT Sensor Signal Voltage (Key On, Engine Off) — expected: ~2.0V - 3.0V on a cold engine; drops to ~0.5V on a fully warm engine.. Failure: Voltage is stuck high (e.g., near 5V) or low, or does not change smoothly as the engine warms up.
• ECT Sensor Circuit Integrity Test (Scan Tool) — expected: With sensor disconnected, scan tool should show >4.6V. With signal and ground pins jumpered, scan tool should show <1.0V.. Failure: If voltage is not >4.6V with the sensor disconnected, there's a short to ground in the harness. If voltage does not drop below 1.0V with the jumper, there's high resistance in the signal or ground circuit.

Scan Tool Commands That Help

• OBD-II Scan Tool (Advanced): Live Data Graphing: ECT, IAT, Ambient Air Temp — On a cold-soaked engine, all three temperature sensors should read within a few degrees of each other. This is the primary test the PCM uses to set P0116. Graphing the ECT during warm-up will clearly show if the thermostat is stuck open (slow, flat rise) or if the sensor is erratic (sharp jumps/drops).

Wiring & Ground Locations

• ECT Sensor Connector — On the thermostat housing (2.4L and 3.2L engines). It is a 2-wire connector.. The connector itself can have corrosion or a broken locking tab, leading to a poor connection and intermittent signals. The two wires are the K2 (ECT Signal) and K900 (Sensor Ground) circuits.
• Engine/Chassis Grounds (General) — Key locations on similar Jeep platforms include the inner fenders, a stud on the engine block (often near the oil dipstick tube), and braided straps from the engine head to the firewall.. The ECT sensor relies on a clean sensor ground path back to the PCM. A corroded main engine or chassis ground can introduce voltage offsets and resistance, causing the PCM to receive an irrational signal from an otherwise good sensor.

Real Owner Repair Stories

• Reddit user in /r/Jeep (Jeep (model not specified, but common issue)) — Check engine light with code P0128 (Coolant Temp Below Thermostat Regulating Temp).
  ❌ Tried (didn't work) Living with the code for 18 months.
  ✅ What actually fixed it Replacing the thermostat finally resolved the code, which had not returned after two weeks. Multiple other users in the thread recommended replacing the thermostat as the primary fix for this code.
• YouTube channel 'Robert Dotterer' (2015 Jeep Cherokee 2.4L) — Check Engine Light with code P0128 and very low coolant.
  ❌ Tried (didn't work) Initially just topping off the low coolant.
  ✅ What actually fixed it After topping off coolant, the technician watched live data and confirmed the engine was warming up too slowly. The final fix was replacing the entire thermostat housing assembly, which includes the thermostat. This highlights how P0116/P0128 often point to a stuck-open thermostat.

When the Usual Fixes Don't Work

• While replacing the ECT sensor or thermostat are the most common hardware fixes, a significant number of cases on this platform are not resolved by replacing parts. On earlier models of the same generation, owners frequently reported replacing the sensor and/or thermostat, only for the P0116 code to return. The final, successful repair was a dealership visit to have the Powertrain Control Module (PCM) software updated ('flashed') per a Technical Service Bulletin. This indicates that for any persistent P0116 code, verifying the PCM has the latest software should be a priority before assuming a hardware failure.

OEM Part Supersession History

• 5149096AB → 5149077AB — Standard part revision/update by the manufacturer.
  Heads up: The new part number (5149077AB) is the correct direct replacement for the original.

Model Year Variations Within This Range

• 2022 vs 2023: The 2.4L I4 engine was available for the 2022 model year but was discontinued for 2023, which primarily offered the 2.0L Turbo and 3.2L V6. This is significant because the 2.4L engine features an ECT sensor integrated into the thermostat housing, making its replacement a more involved job than on the 3.2L V6 where it is a separate, more accessible sensor.