P0057 on 2021 Chrysler Pacifica: O2 Sensor Heater Circuit Low Fixes

What's Unique About the 2021-2021 Chrysler PACIFICA

For the 2021 Chrysler Pacifica with the 3.6L engine, this code has a significant vehicle-specific nuance. Chrysler issued Technical Service Bulletins (TSBs #1805022REVA and #18-051-21) that include P0057 in a list of O2 sensor heater codes that may be resolved by reprogramming (flashing) the Powertrain Control Module (PCM). This is not just a suggestion; it is the most likely cause. The original PCM software has overly sensitive parameters for monitoring the heater circuits. Ignoring this and simply replacing the O2 sensor will likely result in the code returning.

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 is on
• Failure to pass an emissions inspection
• Slight decrease in fuel economy
• Rough idle in some cases, though less common for a downstream sensor issue

Most Likely Causes

1. PCM Software Calibration Issue 🔴 High Probability Documented in manufacturer TSBs #1805022REVA and #18-051-21, which call for a PCM reflash to fix a list of O2 sensor heater circuit codes. The original software parameters are too sensitive.
   How to confirm: A Chrysler dealership or qualified shop can check the current PCM software version against the latest available calibration using their diagnostic tool (wiTECH). This should be the first step.
   Typical fix: Reprogramming (flashing) the Powertrain Control Module with the updated software.
   Est. part cost: $0 (software), Labor cost for flashing typically $100-$200
🎬 Watch: How a Chrysler PCM is professionally reflashed
2. Failed Oxygen Sensor 🟡 Medium Probability The internal heater element within the O2 sensor is a common failure point. It can short out, causing the fuse to blow, or develop an open circuit. This is a common issue across many vehicles, including the Pentastar family.
   How to confirm: Disconnect the sensor and measure the resistance between the two heater circuit pins (usually the two wires of the same color). An infinite resistance reading (OL) indicates an open circuit. A very low reading (near zero ohms) could indicate a short. Typical resistance for a Pentastar O2 sensor is between 3 and 30 Ohms.
   Typical fix: Replace the Bank 2, Sensor 2 oxygen sensor.
   Est. part cost: $45-$80
3. Damaged Wiring or Connector ⚪ Low Probability The sensor is located under the vehicle, exposed to road debris, moisture, and high exhaust temperatures which can damage the wiring harness or connector over time. The harness can melt if it comes into contact with the exhaust pipe.
   How to confirm: Visually inspect the wiring harness and connector leading to the Bank 2, Sensor 2 for any signs of melting, fraying, corrosion, or loose pins. Perform a wiggle test on the harness while monitoring sensor data.
   Typical fix: Repair the damaged section of the harness or clean/replace the connector.
   Est. part cost: $10-$50

Rare But Worth Checking

• Blown Fuse: The O2 sensor heater circuits are often protected by a shared fuse. A shorted sensor can blow this fuse, which may cause multiple heater circuit codes to appear at once. On related Jeep platforms, this is a very common diagnostic step. Check the owner's manual or the fuse box diagram for the specific fuse location, which is in the Power Distribution Center in the engine bay.
• Faulty Powertrain Control Module (PCM): This is rare, but if the software reflash doesn't work and the sensor and wiring are confirmed to be good, the driver circuit within the PCM itself could have failed. This is a last resort diagnosis.

Diagnosis Steps

1. Check for any applicable Technical Service Bulletins (TSBs) for your vehicle's VIN. Specifically, inquire about TSBs #1805022REVA and #18-051-21. This is the most critical first step.
2. If a TSB regarding a PCM reflash exists, have this performed first by a dealer or qualified shop. This resolves the issue in a majority of cases.
3. If no TSB applies or the reflash does not solve the issue, proceed with physical diagnosis.
4. Check the fuse for the O2 sensor heater circuit. On related platforms like the Jeep Grand Cherokee, a shorted O2 sensor often blows a shared fuse, leading to multiple codes. The fuse box is in the engine compartment near the battery.
5. Visually inspect the Bank 2, Sensor 2 oxygen sensor's wiring harness and connector. The sensor is located on the front side of the engine (Bank 2), in the exhaust pipe after the catalytic converter. Look for melting, chafing, or corrosion.
🎬 Watch: Locate the oxygen sensors and emissions components on your Pacifica
6. If the wiring and fuse are okay, disconnect the sensor and test the resistance of the heater element using a multimeter. A reading of infinite ohms (OL) means the sensor has failed. A healthy sensor for a Pentastar engine should read between 3 and 30 ohms.
7. If the sensor's resistance is within spec, check for power and ground at the harness-side connector with the key on, engine off. You should have battery voltage on one pin and a good ground on another. The PCM controls the heater via pulse-width modulation, so you may be checking the control circuit.
8. If power or ground is missing, trace the wiring back to find the break or short.
9. If the sensor, wiring, power, and ground are all good, and the PCM software is up to date, the fault may lie within the PCM itself, though this is rare.

Parts You'll Likely Need

• Bank 2, Sensor 2 Oxygen Sensor (Downstream, Front) (OEM #5149180AB (replaces 5149180AA)) — This is the component identified by the code. The internal heater element is the most common physical failure point if the issue is not software-related.
  Trusted brands: Mopar, Bosch, Denso, NTK
  OEM price range: $70-$125
  Aftermarket price range: $45-$80

Related Codes That Often Appear With This One

• P0031 — Heater circuit low code for Bank 1, Sensor 1. If multiple heater circuit codes appear, it strongly points towards the PCM software issue mentioned in the TSBs or a shared power/ground issue like a blown fuse.
• P0051 — Heater circuit low code for Bank 2, Sensor 1. Similar to P0031, its presence alongside P0057 strengthens the case for a PCM software update or a systemic electrical issue.
• P0037, P0038, P0052, P0058 — These are all O2 sensor heater circuit codes listed in TSB #18-051-21 and #1805022REVA. The appearance of any combination of these codes makes the PCM reflash the most probable solution.

Technical Service Bulletins (TSBs) & Recalls

• 1805022REVA: Lists P0057 as a code that may require a PCM software update. This TSB covers a wide range of O2 heater circuit high and low codes.
• 18-051-21: Also lists P0057 as a code that may be addressed by flashing the PCM. This bulletin reinforces the software-based nature of the problem.

Platform-Specific Known Issues

• Chrysler TSBs #1805022REVA and #18-051-21 list P0057 among several O2 sensor heater codes that may be resolved by a PCM software update. This is a critical first check before replacing any parts.
• The 3.6L Pentastar engine family across multiple platforms (Jeep, Dodge, Ram) is known for O2 heater circuit issues, reinforcing that this is a well-documented problem with known solutions.

Mechanic-Grade Diagnostic Values

• O2 Sensor Heater Element Resistance — expected: 3 to 30 Ohms when measured at room temperature.. Failure: A reading of infinity (OL) indicates an open circuit (failed heater), while a reading near zero indicates a short circuit. Any reading outside the 3-30 Ohm range is a fault.
🎬 See how to test O2 sensor heater circuits with a multimeter
• O2 Sensor Heater Power Supply Voltage — expected: Battery voltage (approx. 12V) should be present at one of the heater circuit pins on the harness-side connector with the ignition on.. Failure: Voltage close to zero indicates an open circuit or blown fuse in the power supply.
• O2 Sensor Heater Control Circuit (Scan Tool) — expected: When actuating the O2 Heater Test with a scan tool, a test light connected to the control circuit pin should flash, or a multimeter/oscilloscope should show a pulse-width modulated ground signal.. Failure: No flashing light or no voltage change/pulse indicates a problem with the PCM driver or the wiring to the PCM.

Scan Tool Commands That Help

• wiTECH (Chrysler/FCA Dealer Tool): O2 Heater Test — This is a bidirectional test used to command the PCM to activate the specific O2 sensor heater circuit. It is used after confirming the sensor and wiring have correct resistance. If the command is sent but the circuit doesn't activate (verified with a test light or meter), it points towards a faulty PCM driver. The DTC may need to be cleared before the test will run.

Wiring & Ground Locations

• Power Distribution Center (PDC) / Underhood Fuse Box — Located in the engine compartment, on the driver's side, near the battery.. This fuse box contains the fuse(s) that supply power to the oxygen sensor heater circuits. A shorted sensor or wire can blow a fuse here, which is a common diagnostic step to check before replacing parts.
• O2 Sensor Heater Wires — On a typical 4-wire Mopar O2 sensor, the two wires of the same color (e.g., both white or both black) are for the heater circuit.. These are the specific wires/pins that must be tested for resistance on the sensor side, and for power/ground on the harness side, to diagnose P0057.

OEM Part Supersession History

• 5149180AA → 5149180AB — Standard part revision by the manufacturer.
  Heads up: The new part number (5149180AB) is the correct replacement for the original. Using the old stock (5149180AA) is not recommended.