P2251 on 2013-2015 Dodge DART: O2 Sensor Circuit Causes and Fixes

What's Unique About the 2013-2015 Dodge DART

For the Dodge Dart, particularly models with the 2.4L engine, this code is specifically mentioned in a series of manufacturer Technical Service Bulletins (TSBs). These bulletins, which also apply to the related Chrysler 200, indicate that the code can be triggered by a software issue within the Powertrain Control Module (PCM), not just a physical part failure. Before replacing any parts, it's crucial to check if the vehicle's software is up to date, as a simple reflash at a dealership could be the correct and most cost-effective solution.

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
• Decreased fuel economy by 5-10%.
• Rough or fluctuating idle.
• Engine hesitation or lack of power during acceleration.
• Failing an emissions test
• Noticeable smell of unburned fuel from the exhaust.

Most Likely Causes

1. Faulty Upstream Oxygen Sensor (Bank 1, Sensor 1) 🔴 High Probability O2 sensors are wear-and-tear items that operate in a harsh exhaust environment. The internal heating element or sensing circuit can fail, creating the 'open circuit' condition reported by the P2251 code.
   How to confirm: After checking wiring, test the sensor's internal heater circuit resistance with a multimeter; a typical reading is between 2-5 Ohms. 🎬 See this video for quick steps to test your oxygen sensor. An open circuit (>10 kΩ) indicates a failed sensor. A professional can watch its live data on a scan tool to see if it's responding correctly.
   Typical fix: Replace the upstream oxygen sensor.
   Est. part cost: $45-$130
2. Outdated Powertrain Control Module (PCM) Software 🟡 Medium Probability Dodge and Chrysler released multiple TSBs (e.g., #18-006-15 REV-G, 18-023-16 REV. C) specifically for 2013-2015 Darts and 2015 Chrysler 200s with the 2.4L engine, which list P2251 as a code that can be resolved by a PCM software update.
   How to confirm: A Dodge dealership or a qualified shop with a wiTECH scan tool can check the current software calibration ID against the latest available version listed in the TSBs.
   Typical fix: Reprogram the PCM with the latest software. This must be done by a dealer or a properly equipped independent shop. The TSB also notes the TCM should be updated at the same time.
   Est. part cost: $0 (if under warranty) - $250
3. Damaged Wiring or Connectors ⚪ Low Probability The O2 sensor harness is routed near hot exhaust components. Over time, the protective loom can degrade, allowing wires to melt or chafe, leading to an open circuit. A Reddit user with a P2251 code specifically suggested checking for wires that may have burned on the exhaust.
   How to confirm: Visually inspect the wiring harness from the sensor to the main engine harness. Check the connector for corrosion, bent pins, or loose connections. Use a multimeter to check for continuity on the negative current control wire between the sensor connector and the PCM.
   Typical fix: Repair the damaged section of the wire or replace the connector pigtail.
   Est. part cost: $15-$50

Rare But Worth Checking

• Exhaust Leak: An exhaust leak near the sensor can allow outside air to enter the exhaust stream, skewing the sensor's readings and sometimes triggering circuit-related codes. Check for cracked manifolds or leaking gaskets.
• Faulty Powertrain Control Module (PCM): This is the least likely cause. The internal driver circuit in the PCM that controls the O2 sensor can fail. This should only be considered after all other possibilities, including the software update, have been exhausted. A replacement PCM can cost several hundred dollars and requires programming to the vehicle's VIN.

Diagnosis Steps

1. Scan for any other trouble codes. If other O2 sensor codes (e.g., heater circuit codes) are present, address them first.
2. For 2.4L models, check for applicable TSBs, such as 18-006-15, 18-023-16, or 18-022-17 and their revisions. If the TSB applies and the software has not been updated, this should be the first repair step.
3. Perform a thorough visual inspection of the Bank 1, Sensor 1 (upstream) O2 sensor's wiring and connector. Look for any signs of melting, chafing, or corrosion from the sensor up to where it joins the main harness.
4. With the ignition off, disconnect the sensor and use a multimeter to check the resistance of the sensor's heater circuit. A normal reading is typically 2-5 Ohms. An infinite resistance reading confirms an open circuit within the sensor.
5. If the sensor tests good, check for continuity on the negative current control wire between the sensor's harness connector and the PCM connector. Check for voltage on the power supply wire 🎬 Watch: How to find and replace the oxygen sensor fuse. with the key on.
6. If the wiring and sensor are confirmed to be 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

• Upstream Oxygen Sensor (Bank 1, Sensor 1) - 2.4L Engine (OEM #68087364AA) — This is the most common component to fail and directly cause the P2251 open circuit code if a software update is not the issue. The OEM part number applies to the 2.4L engine.
  Trusted brands: Mopar, NTK, Denso (234-5150), Bosch
  OEM price range: $90-$135
  Aftermarket price range: $45-$90
• Upstream Oxygen Sensor (Bank 1, Sensor 1) - 2.0L Engine (OEM #68192625AA) — For the 2.0L engine, this is the corresponding sensor that would be replaced for a P2251 code if the part is faulty.
  Trusted brands: Mopar, NTK, Denso, Bosch (18126), Walker (350-35162)
  OEM price range: $100-$150
  Aftermarket price range: $50-$95

Related Codes That Often Appear With This One

• P219A — This code for 'Bank 1 Air-Fuel Ratio Imbalance' is listed in the exact same TSBs as P2251 for the Dart, Cherokee, and 200. A faulty O2 sensor cannot provide accurate data, leading the PCM to detect an imbalance.
• P2172 — 'High Airflow/Vacuum Leak Detected' is another code frequently mentioned alongside P2251 in the relevant software update TSBs, indicating the PCM software improvements address multiple related diagnostic strategies.

Technical Service Bulletins (TSBs) & Recalls

• 18-006-15 REV-G: "Flash: 2.4L Powertrain Diagnostic and System Improvements" - This bulletin explicitly lists P2251 as a code that can be fixed by reprogramming the PCM on 2013-2015 Darts with the 2.4L engine.
• 18-023-16 REV. C: Supersedes earlier versions and also covers the 2015 Chrysler 200, listing P2251 as a target DTC for the PCM reflash.
• 18-022-17 REV. A: Another revision of the software update bulletin for the 2.4L engine in the Dart and 200, which also includes P2251.
• 18-005-15 REV. E: A similar PCM flash bulletin for the 2014-2015 Jeep Cherokee (KL) with the 2.4L engine, also addressing code P2251.

Platform-Specific Known Issues

• A significant number of 2013-2015 Dodge Darts with the 2.4L engine may trigger P2251 due to a software glitch. TSB #18-006-15 and its subsequent revisions (like 18-023-16 and 18-022-17) direct technicians to reprogram the PCM with updated software to resolve this and other diagnostic trouble codes. This same issue and TSB fix applies to the 2015 Chrysler 200 and 2014-2015 Jeep Cherokee with the same 2.4L engine.

Mechanic-Grade Diagnostic Values

• O2 Sensor Heater Circuit Resistance — expected: 2-5 Ohms. Failure: An open circuit reading (>10 kΩ) or infinite resistance indicates a failed internal heater element.
• Upstream O2 Sensor Live Data Voltage (at idle) — expected: Fluctuating rapidly between approximately 0.1V and 0.9V.. Failure: Voltage is stuck, sluggish, or flat-lined.
• O2 Sensor Heater Power Supply — expected: Approximately 12V (Battery Voltage) at the sensor connector with Key On, Engine Off.. Failure: No voltage indicates a problem with the power supply from the fuse or relay.

Scan Tool Commands That Help

• wiTECH or equivalent full-function scan tool: O2 Heater Actuation Test — This bidirectional control allows a technician to command the PCM to activate the O2 sensor heater circuit independently of engine conditions. It is used to verify if the PCM driver, wiring, and heater element are capable of functioning when commanded. A successful test (showing current flow on an amp clamp) with the code still present points towards a logic or software issue.

Wiring & Ground Locations

• PCM Connector C1 (Orange Insert) — The Powertrain Control Module (PCM) on the 2.0L/2.4L engines is located at the left front of the engine compartment.. The O2 sensor 1/1 heater control circuit wire terminates at a specific pin in this connector. For Chrysler NGC controllers, the PCM pulses 12 volts to the heater; testing at this pin can confirm if the PCM is sending the signal.
• Engine to Chassis Ground — A primary ground strap runs from the engine block/transmission area to the driver's side frame rail, accessible after removing the plastic belly pan and/or driver's side wheel splash guard.. Multiple owners have reported that corrosion at this main ground point causes a wide range of electrical issues, including no-start conditions. While not specific to P2251, a poor ground can create floating voltages and unpredictable behavior in sensor circuits that rely on a stable ground reference.
• Fuse F87 — In the under-hood fuse box located next to the battery.. On some Dodge Dart configurations, fuse F87 is dedicated to the oxygen sensor heaters. If this fuse is blown, the heater circuit will be open. If the fuse is missing, power may be supplied via a general engine control module fuse.

Real Owner Repair Stories

• YouTube channel 'Fix it Angel' (2013 Dodge Dart 2.0L) — No crank, no start condition.
  ❌ Tried (didn't work) Replacing the starter motor.
  ✅ What actually fixed it The vehicle had a bad engine-to-chassis ground. The ground stud on the driver's side frame rail was corroded. Cleaning the corrosion from the ground stud, the wire terminal, and the nut with a wire brush restored the connection and resolved the no-start issue for $0.

OEM Part Supersession History

• 68087364AA → 68195741AA — Part consolidation and potential design update.
  Heads up: Part interchange data shows 68195741AA as a valid replacement for 68087364AA for the 2.4L engine in the Dart, as well as the Chrysler 200 and Jeep Cherokee.