P0206 on 2014-2020 Ram 2500: Injector Circuit/Open Causes and Fixes

What's Unique About the 2014-2020 Ram 2500

For this generation of Ram 2500, Chrysler/FCA issued several Technical Service Bulletins (TSBs) including #18-045-15 and #1805314REVB to address this specific code family (P0201-P0206). [Bulletin #18-045-15, Bulletin #1805314REVB] These TSBs updated the PCM software to change the code from a one-trip to a two-trip fault, making it less sensitive and preventing false Check Engine Lights from intermittent connection issues. [Bulletin #18-045-15, Bulletin #1805314REVB] On 6.7L Cummins models, the injectors for cylinders 4, 5, and 6 are grouped on the same electrical bank (Bank 2). If a significant short circuit occurs in the wiring for one of these injectors, the PCM will shut down the entire bank to protect the internal driver circuit, often logging codes P0204, P0205, P0206, and P2149 simultaneously.

Diagnostic Flowchart

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

Generation note: This range covers the end of the Fourth Generation (2014-2018) and the start of the Fifth Generation (2019-2020) Ram 2500. While the code's meaning is consistent, 2019-2020 Cummins models used a Bosch CP4 high-pressure fuel pump that was subject to a major safety recall (Y78) which could cause a stall or no-start condition, sometimes accompanied by injector circuit codes. [6, Bulletin #18-099-22 REV. A]

Symptoms You May Notice

• Check Engine Light is on
• Rough or shaking idle
• Engine misfire or stumble
• Noticeable loss of power and acceleration
• Poor fuel economy
• Engine may not start (in some cases) [Bulletin #18-099-22 REV. A]
• Electronic Throttle Control (ETC) or 'lightning bolt' light may illuminate intermittently

Most Likely Causes

1. Faulty #6 Fuel Injector 🔴 High Probability Injectors are wear items. On 2019-2020 Cummins models, failure of the CP4 high-pressure fuel pump (Recall Y78) can send debris through the fuel system, damaging the injectors. On all models, the internal solenoid coil can simply fail and create an open circuit.
   How to confirm: The most definitive test is to swap the #6 injector with an adjacent one (like #5). Clear codes and run the engine. If the code changes to P0205, the injector is bad. Alternatively, check the injector's resistance with a multimeter. A 6.7L Cummins injector should be <1 Ohm. A HEMI injector should be ~12-16 Ohms. An infinite reading means the injector is open and faulty.
   Typical fix: Replace the faulty fuel injector. On high-mileage Cummins engines, it's often recommended to replace the set of three on the same bank (4, 5, 6) or all six.
   Est. part cost: $300-$800 for Cummins, $70-$150 for HEMI
2. Wiring Harness or Connector Issue 🔴 High Probability Engine vibrations and intense heat cause wiring to chafe, break, or connectors to become loose. On the 6.7L Cummins, the valve cover pass-through harness (which is integrated with the valve cover gasket) is a very common failure point, becoming brittle and cracking over time.
   How to confirm: Visually inspect the wiring harness leading to injector #6 for any signs of damage, melting, or corrosion. On Cummins engines, pay close attention to the main pass-through connector on the valve cover. Perform a continuity test on the two wires for the #6 injector from the injector connector back to the PCM connector. Resistance should be less than 10 ohms.
   Typical fix: Repair the damaged section of wire or replace the injector connector pigtail. If the under-valve-cover harness on a Cummins has failed, it must be replaced.
   Est. part cost: $20-$200
3. Loose Injector Terminal Nuts (6.7L Cummins) 🟡 Medium Probability Vibration can cause the small 8mm nuts securing the wires to the top of the injector solenoid to loosen over time, creating an open or intermittent circuit.
   How to confirm: Remove the oil fill cap and the small access cover on the valve cover to access the injector terminals. Check if the nuts on the rearmost injector (#6) are loose.
   Typical fix: Tighten the terminal nuts to the correct specification, which is very low: 11-13 inch-pounds (1.2-1.5 Nm). Do not overtighten, as this can damage the injector solenoid.
   Est. part cost: $0

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): This is rare. The internal driver circuit for the injector bank can fail. This should only be considered after the injector and all wiring have been thoroughly tested and confirmed to be good. It is more likely if codes for the entire bank (P0204, P0205, P0206) are present and do not resolve with wiring or injector replacement.

Diagnosis Steps

1. Scan the PCM for trouble codes and confirm P0206 is active. Note any other codes present, especially P0306, P2149, or other injector codes.
2. Visually inspect the wiring harness and connector for injector #6. On a 6.7L Cummins, pay special attention to the main pass-through connector on the valve cover.
3. For Cummins engines, check the tightness of the injector terminal nuts under the valve cover access plate. Torque to 11-13 in-lbs if loose. Do not overtighten.
4. Use a noid light to test the signal at the injector connector. Disconnect the harness, plug in the noid light, and start the engine. The light should flash steadily, indicating the PCM is sending a signal. If it doesn't flash or stays on constantly, the problem is in the wiring or PCM.
5. If the noid light flashes, the next step is to test the injector itself. The most reliable method is to swap the #6 injector with an adjacent one (e.g., #5).
6. Clear the codes, start the engine, and see which code returns. If P0205 appears, the injector is faulty. If P0206 returns, the problem is in the wiring specific to the #6 cylinder.
7. If wiring is suspected, perform a continuity test on both wires from the injector #6 connector back to the PCM connector. Resistance should be less than 10 ohms. Also check for shorts to ground and to each other.
8. If the injector and wiring are confirmed to be good after these tests, the PCM is the likely, though rare, culprit.

Parts You'll Likely Need

• Fuel Injector (6.7L Cummins) (OEM #68444791AA (Bosch Remanufactured)) — This is the most common component to fail, causing an open circuit internally.
  Trusted brands: Bosch, Mopar
  OEM price range: $400-$800
  Aftermarket price range: $300-$600
• Fuel Injector (5.7L/6.4L HEMI) (OEM #5184085AD) — The injector fails internally, causing an open circuit.
  Trusted brands: Mopar, Bosch, Standard Motor Products
  OEM price range: $100-$180
  Aftermarket price range: $70-$150
• Valve Cover Pass-Through Harness (6.7L Cummins) (OEM #68005149AA (Also sold as a gasket/harness assembly)) — This harness, which runs under the valve cover to connect the injectors, is a known high-failure item due to constant heat and vibration, leading to brittle wires and open circuits.
  Trusted brands: Mopar, Cummins
  OEM price range: $100-$200
  Aftermarket price range: $70-$150
• Fuel Injector Connector Pigtail (OEM #05183448AA (HEMI)) — The connector at the injector can become brittle from heat and vibration, causing a poor connection or broken wires.
  Trusted brands: Mopar, Dorman
  OEM price range: $30-$50
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• P0306 — This code means 'Cylinder 6 Misfire Detected'. A fault in the injector circuit (P0206) prevents proper fueling, which directly causes a misfire on that cylinder.
• P0204, P0205 — On the 6.7L Cummins, injectors 4, 5, and 6 are on the same bank. A major short in the harness or a failure of the PCM's bank driver can disable all three to protect the circuit, logging codes for the entire bank.
• P2149 — This code is for 'Fuel Injector Group 'B' Supply Voltage Circuit/Open' and points to a problem with the power supply for injectors 4, 5, and 6 on the Cummins engine, often appearing alongside the individual circuit codes when a bank-wide shutdown occurs.

Technical Service Bulletins (TSBs) & Recalls

• 18-099-22 REV. A: Links P0206 to a potential no-start condition and notes it is superseded by recall Y78.
• 18-045-15 REV A: Details a software update changing P0206 to a two-trip fault.
• 18-099-22: Original bulletin linking P0206 to a no-start condition.
• 18-045-15: Original bulletin for the software update to make the fault two-trip.
• 1805314REVB: Notes a software change for P0201-P0206 to prevent MIL illumination when no defect is present.

Platform-Specific Known Issues

• Software Sensitivity: TSBs #18-045-15 REV A and #1805314REVB were released to change the P0201-P0206 fault logic from a one-trip to a two-trip fault. This was done to reduce the frequency of the Malfunction Indicator Lamp (MIL) illuminating for intermittent, non-critical faults that might resolve themselves. [Bulletin #18-045-15 REV A, Bulletin #1805314REVB]
• No-Start Condition: TSB #18-099-22 REV. A notes that a P0206 fault, among others, can lead to a no-start condition. This TSB was later superseded by recall Y78. [Bulletin #18-099-22 REV. A]
• HPFP Recall (Y78): On 2019-2020 Cummins models, a failing CP4 high-pressure fuel pump can send metal debris into the fuel system, damaging the injectors and causing codes like P0206.

Mechanic-Grade Diagnostic Values

• 6.7L Cummins Fuel Injector Resistance — expected: Less than 1.0 Ohm, but greater than 0 Ohms (typically 0.3-0.5 Ohms).. Failure: A reading of infinite resistance (OL) indicates an open circuit; 0 Ohms may indicate a short.
• 6.4L/5.7L HEMI Fuel Injector Resistance — expected: Approximately 12-16 Ohms.. Failure: A reading significantly outside this range, especially an open circuit (OL), indicates a failed injector.
• Injector Circuit Wiring Continuity (PCM to Injector) — expected: Less than 10 Ohms.. Failure: Resistance greater than 10 Ohms indicates an open or high resistance in the wiring harness.
• Injector Circuit Short to Ground — expected: Greater than 100k Ohms between either injector terminal and the engine block/ground.. Failure: Any low resistance reading indicates a short to ground.
• 6.7L Cummins Injector Pulse Width (at hot idle) — expected: Approximately 0.5 – 0.9 milliseconds (ms).. Failure: Scan tool data showing no pulse width for cylinder 6, or values that are drastically different from other cylinders, can indicate a control problem.

Scan Tool Commands That Help

• wiTECH, Autel, Launch, AlfaOBD: Injector Kill Test / Cylinder Contribution Test — This bidirectional command allows a technician to disable one injector at a time while the engine is running. If disabling cylinder #6 causes no change in engine idle or roughness, it confirms that cylinder wasn't contributing, pointing strongly to a problem with that injector or its circuit.
• wiTECH or equivalent professional scan tool: Fuel Pressure Override Test — This test commands the fuel system to produce maximum rail pressure (around 26,000 PSI) to stress the system and measure injector return flow under load, which can help diagnose injector health beyond just the electrical circuit.
• wiTECH or equivalent professional scan tool: Program IQA (Injector Quantity Adjustment) Code — This is NOT required for 2013-2018 models. For other model years, this function is used after replacing a Cummins injector to program the new injector's specific flow characteristics into the ECM.

Wiring & Ground Locations

• Injector Harness Connector (Bank 2) — On the driver's side of the 6.7L Cummins engine, there are two large pass-through connectors on the valve cover. The REAR connector is for cylinders 4, 5, and 6.. This is the main connection point for the entire injector bank that includes cylinder 6. A problem at this single connector can cause P0206, often along with P0204 and P0205.
• PCM Connector C1 (6.7L Cummins) — On the Engine Control Module (ECM), located on the driver's side of the engine block.. This connector contains the driver circuits for injector bank 2 (cylinders 4, 5, 6). The specific circuits for injector #6 are (K658) for the High Side Driver and (K58) for the Low Side Driver. Probing these specific pins is necessary for accurate electrical diagnosis of the circuit back to the computer.
• Engine Block Grounds — On the 6.7L Cummins, there are primary ground cables from the battery to the engine block on both the driver and passenger sides.. While not a direct cause of a single injector code, a poor engine ground can cause a host of intermittent electrical issues and incorrect sensor readings. Ensuring these are clean and tight is a fundamental step in any electrical diagnosis.

Real Owner Repair Stories

• Dodge Diesel - Ram Truck Forum user (2007 Ram 6.7L Cummins (similar architecture to 2014-2018)) — Intermittent Check Engine Light with code P0206.
  ❌ Tried (didn't work) Testing the injector solenoid (showed good resistance), Checking for continuity to ground (showed no short)
  ✅ What actually fixed it The problem was intermittent and ultimately resolved by replacing the valve cover gasket, which includes the integrated injector wiring harness. The user noted that a short in any injector circuit can cause the ECM to shut down the entire bank.
• YouTube video by 'Fixing P0206 on Dodge Ram/Cummins' (Dodge Ram with 6.7L Cummins) — P0206 trouble code.
  ❌ Tried (didn't work) N/A, went straight to testing.
  ✅ What actually fixed it The injector solenoid for cylinder #6 was faulty. The video demonstrates testing the solenoid's resistance (showed bad) compared to a good one, and then replacing only the solenoid by grinding down a socket to fit, avoiding the need to remove the entire injector body.

OEM Part Supersession History

• 68444791AA → R8444791AA, R8504672AA — Standard part number evolution, often indicating a remanufactured unit or minor revision.
  Heads up: Part number 68444791AA is specified for 2019-2020 Ram 2500 with the 6.7L Cummins. R8444791AA is often the remanufactured equivalent. Always verify fitment with VIN as standard and high-output engines may use different injectors.

Model Year Variations Within This Range

• 2013-2018: Fuel injectors for these 6.7L Cummins model years do NOT require Injector Quantity Adjustment (IQA) codes to be programmed into the ECM after installation.
• 2019-2020: These models used the Bosch CP4 high-pressure fuel pump, which was subject to recall Y78. A failure of this pump is a known cause of injector damage due to metal debris, which can lead to a P0206 code.