P0111 on 2017-2021 Chrysler Pacifica Hybrid: IAT Sensor Causes and Fixes

What's Unique About the 2017-2021 Chrysler PACIFICA PLUG-IN HYBRID

For the Pacifica Hybrid, the P0111 code is specifically mentioned in a Technical Service Bulletin (TSB #18-044-26) alongside the Ambient Air Temperature Sensor code (P0071). This indicates that the vehicle's computer closely cross-references these two sensors. An issue with one can easily trigger a fault in the other, and the fix may require a software update at the dealership to adjust the PCM's sensitivity, rather than just a simple part replacement. This pattern of software fixes for sensor range codes is seen in other FCA hybrid models as well.

Diagnostic Flowchart

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

Symptoms You May Notice

• Check Engine Light (MIL) is on
• Reduced fuel economy
• Rough idle or hesitation during acceleration
• Hard starting, especially in cold weather
• Engine may run rough when idling

Most Likely Causes

1. Faulty Intake Air Temperature (IAT) Sensor 🔴 High Probability The sensor is a simple thermistor that can degrade over time due to heat cycles and exposure to the elements, causing its readings to become inaccurate. It is a widely used part across many Chrysler/Dodge/Jeep vehicles.
   How to confirm: Use a scan tool to compare the IAT reading to the ambient air temperature reading with the engine cold; they should be nearly identical. If the IAT reading is stuck at a very high or low temperature or doesn't change as the engine warms up, the sensor is likely bad. You can also test the sensor's internal resistance with a multimeter and compare it to a temperature/resistance chart; for example, it should be around 9k-11k Ohms at 77°F (25°C).
   Typical fix: Replace the Intake Air Temperature sensor. It is a twist-in sensor located on the air intake duct between the air filter box and the throttle body. The OEM Mopar part number is 5149182AB. 🎬 Watch: Step-by-step IAT sensor replacement on a Pacifica Hybrid.
   Est. part cost: $20-$50
2. Powertrain Control Module (PCM) Software Update Needed 🟡 Medium Probability TSB #18-044-26 specifically addresses P0111 appearing with P0071, which often points to the PCM's diagnostic logic being too sensitive. The manufacturer issues software updates to correct these logic errors, a common practice for many powertrain-related DTCs.
   How to confirm: A Chrysler dealership or a qualified shop with a wiTECH scan tool can check if your vehicle's PCM has the latest software version by connecting to the vehicle and checking against available updates. They can also confirm if TSB #18-044-26 applies to your VIN.
   Typical fix: Reprogram the PCM with the updated software provided by the manufacturer. This must be done by a dealership or a properly equipped independent shop using a wiTECH scan tool while the vehicle is connected to a stable battery charger.
   Est. part cost: $0-$200
3. Damaged Wiring or Loose Connector 🟡 Medium Probability The IAT sensor connector or its wiring can become corroded, loose, or damaged from engine vibrations and heat, leading to an intermittent or lost signal.
   How to confirm: Visually inspect the IAT sensor's connector and wiring for any signs of corrosion, fraying, or damage. Wiggle the connector and wiring with the engine running while monitoring the IAT data on a scan tool to see if the reading fluctuates wildly. Check for continuity on the signal wire between the sensor connector and the PCM.
   Typical fix: Clean the connector pins with electrical contact cleaner or repair/replace the damaged section of the wiring harness.
   Est. part cost: $5-$100
4. Dirty or Clogged Engine Air Filter ⚪ Low Probability A severely clogged air filter can restrict airflow across the IAT sensor, preventing its temperature from changing as quickly as the PCM expects, which can trigger a performance range fault. A YouTube tutorial on Pacifica Hybrid IAT sensor replacement specifically recommends checking the air filter first.
   How to confirm: Visually inspect the engine air filter. If it is visibly dirty, clogged with debris, or has not been changed in a long time, it should be replaced.
   Typical fix: Replace the engine air filter.
   Est. part cost: $20-$40

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): While rare, the internal circuits of the PCM that process the IAT sensor signal can fail. This should only be considered after all other possibilities, including software updates, have been exhausted. A full PCM replacement can cost over $500 plus programming.

Diagnosis Steps

1. Check for Technical Service Bulletins (TSBs). Specifically, see if TSB #18-044-26 applies to your vehicle's VIN at a dealership.
2. Using an OBD-II scanner, read the live data for the Intake Air Temperature (IAT) and Ambient Air Temperature (AAT) sensors with the engine cold. The readings should be within a few degrees of each other.
3. Start the engine and monitor the IAT reading. It should gradually increase as the engine bay warms up. If it remains static or shows an illogical value (e.g., -40°F), the sensor or its circuit is faulty.
4. Visually inspect the IAT sensor, its connector, and wiring for any signs of damage, corrosion, or loose connections. The sensor is located on the air intake duct and is a simple twist-in component.
5. Inspect the engine air filter. A severely clogged filter can cause this code and should be replaced if dirty.
6. If the wiring looks good, test the sensor's resistance with a multimeter and compare it to the specifications in a service manual. At room temperature (~77°F/25°C), a good sensor should read approximately 9,000-11,000 ohms.
🎬 See how to test and replace your IAT sensor.
7. If the sensor and wiring test good, the issue is very likely a software glitch, and a PCM update should be performed by a dealer or qualified shop.

Parts You'll Likely Need

• Intake Air Temperature Sensor (OEM #5149182AB) — This is the most common hardware failure for this code. The sensor is a simple thermistor that can fail over time, providing inaccurate readings to the PCM.
  Trusted brands: Mopar, Standard Motor Products, Delphi
  OEM price range: $30-$50
  Aftermarket price range: $20-$40

Related Codes That Often Appear With This One

• P0071 — As noted in TSB #18-044-26, this code for Ambient Air Temperature Sensor Performance often appears with P0111. The PCM compares these two sensors, and a fault in one's logic can trigger a code for the other.

Technical Service Bulletins (TSBs) & Recalls

• 18-044-26: Malfunction Indicator Lamp (MIL) illumination for P0111-00 - Intake Air Temperature Sensor 1 Circuit Range Performance and/or P0071-00 - Ambient Air Temperature Sensor Performance.

Platform-Specific Known Issues

• TSB #18-044-26 indicates that P0111 may be set along with P0071 (Ambient Air Temperature Sensor Performance) due to overly sensitive PCM diagnostic logic. The prescribed fix is often a software update, not necessarily a hardware replacement.
• On a Reddit thread, an owner of a 2018 Pacifica with the 3.6L engine replaced the 'Air Charge Temp Sensor' as one of several parts in an attempt to resolve a persistent rough idle, which is a known symptom of a failing IAT sensor.

Mechanic-Grade Diagnostic Values

• IAT Sensor Resistance (disconnected) — expected: Resistance should decrease as temperature increases. Common values: ~32,650 Ohms at 32°F (0°C); ~9,000-11,000 Ohms at 77°F (25°C); ~2,000 Ohms at 158°F (70°C).. Failure: An open circuit (infinite resistance) or short circuit (near zero resistance) indicates a failed sensor. A reading that doesn't change with temperature also indicates failure.
• IAT Sensor Signal Voltage (live data) — expected: Should be within a range of approximately 0.5V (hot) to 4.5V (cold). On a cold start, the reading should be very close to the Ambient Air Temperature sensor reading.. Failure: A voltage stuck near 5.0V indicates an open circuit (P0113). A voltage stuck near 0V indicates a short circuit (P0112). A reading that doesn't change as the engine warms up indicates a performance fault (P0111).
• IAT Sensor Connector Voltage (Key On, Engine Off) — expected: One wire should have a 5V reference from the PCM. The other is the signal return/ground.. Failure: Absence of the 5V reference points to a wiring or PCM issue, not a sensor failure.

Scan Tool Commands That Help

• wiTECH (Dealer Tool): PCM Reprogramming / Software Update — This is the specific fix called for by TSB #18-044-26 when P0111 is present, especially if accompanied by P0071. It should be performed if the sensor and wiring test correctly, as it adjusts the PCM's sensitivity to prevent false codes.

Wiring & Ground Locations

• PCM Connector C2, Pin 17 — At the Powertrain Control Module (PCM). The PCM is located in the engine bay.. This is the specific pin for the IAT Signal wire (typically Dark Blue/Green). A technician can backprobe this pin to verify the signal is reaching the PCM, or test for continuity between this pin and the sensor connector to rule out a broken wire.
• IAT Sensor Connector — On the air intake duct, between the air filter housing and the throttle body.. This 2-pin connector is a common failure point. One pin receives the 5V reference from the PCM, and the other is the signal return. Checking for voltage and good pin contact here is a primary diagnostic step.

Real Owner Repair Stories

• Reddit user on r/volt (2013 Chevrolet Volt (Demonstrates a similar software-related issue)) — Check engine light with P0111 code appearing during hot weather.
  ❌ Tried (didn't work) The dealer initially suggested replacing the sensor.
  ✅ What actually fixed it A PCM software update as specified in a GM Technical Service Bulletin. The TSB explicitly stated not to replace the sensor for this condition, as the fault was due to incorrect software calibration for high ambient temperatures. This parallels the Chrysler TSB for the Pacifica Hybrid.

OEM Part Supersession History

• 5149182AA → 5149182AB — Standard part revision by the manufacturer. The new part is a direct replacement.

Model Year Variations Within This Range

• 2017-2021: The IAT sensor on the Pacifica Hybrid is a standalone, two-wire sensor located in the intake duct. This is important to note because some earlier applications of the 3.6L Pentastar engine (e.g., 2011-2014 minivans) integrated the IAT sensor into the Manifold Absolute Pressure (MAP) sensor. Technicians familiar with older models may look in the wrong place or for the wrong part.