P0205 on 2014-2020 Ram 2500: Injector Circuit 5 Malfunction Causes and Fixes

What's Unique About the 2014-2020 Ram 2500

On the Ram 2500, the most likely cause for P0205 differs significantly between the Cummins diesel and Hemi gasoline engines. For the 6.7L Cummins, a faulty under-valve-cover wiring harness is a very common point of failure; on many of these model years, this harness is integrated directly into the valve cover gasket, making it a single assembly. For the Hemi engines, while wiring can be the cause, the fuel injector itself is a more frequent culprit. Furthermore, for 2019-2020 Cummins models, this code is listed in TSB 18-099-22 REV. A as a potential symptom of a failing high-pressure CP4 fuel pump, which was subject to recall Y78.

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 third generation (2014-2018) and the start of the fourth generation (2019-2020) Ram 2500. The diagnostic principles for a P0205 code are consistent, though specific part numbers differ. Notably, the 2019-2020 models with the 6.7L Cummins have a known issue with the CP4 fuel pump that can trigger this code.

Symptoms You May Notice

• Check Engine Light is on
• Engine running rough or misfiring, especially at idle
• Hesitation and loss of power during acceleration
• Reduced fuel economy
• Engine may not start [TSB #18-099-22 REV. A]
• Engine knocking or popping sounds
• Vehicle may enter 'limp mode' with restricted speed.
🎬 Watch: Overview of causes and fixes for the P0205 code

Most Likely Causes

1. Faulty Injector Wiring Harness (Especially 6.7L Cummins) 🔴 High Probability → Shop Engine Wiring Harness On Cummins engines, the wiring harness located under the valve cover is subjected to constant heat cycles and oil exposure, causing it to become brittle and fail over time. On many 2014+ models, this harness is integrated into the valve cover gasket itself, a well-documented failure point.
   How to confirm: Remove the valve cover and visually inspect the wiring going to injector #5 for cracks, breaks, or oil saturation. Perform a 'wiggle test' on the connector; if the idle changes, the harness is likely the issue. Test for continuity on each wire from the main pass-through connector to the injector pins with a multimeter. 🎬 See this guide on troubleshooting Cummins injector circuits An open loop (OL) reading indicates a broken wire.
   Typical fix: Replace the injector wiring harness. On 2014-2018 models, this often means replacing the entire valve cover gasket with the integrated harness (Cummins P/N 5367847).
   Est. part cost: $90-$260
2. Failed Fuel Injector 🟡 Medium Probability → Shop Fuel Injector The internal solenoid coil of the injector can fail, creating an open or shorted circuit. This is a common failure on both Hemi and Cummins engines with higher mileage. A failing high-pressure fuel pump on 2019-2020 Cummins can also send debris that damages the injectors.
   How to confirm: Disconnect the injector and measure its resistance with a multimeter. For a 6.7L Cummins, a good injector should read less than 1.0 ohm but greater than 0. For a 6.4L Hemi, it's typically 12-16 ohms. An 'OL' (Open Loop) reading indicates a failed injector. The most definitive test is to swap the #5 injector with an adjacent one (like #6). If the code changes to P0206, the injector is bad.
   Typical fix: Replace the faulty fuel injector (e.g., Mopar #68444791AA for Cummins). It is highly recommended to replace the high-pressure connector tube (e.g., Mopar #4935974 for Cummins Cyl 5) at the same time, as it is a one-time use part.
   Est. part cost: $150-$700
3. Damaged External Wiring or Connector ⚪ Low Probability Rodents are known to chew on engine wiring, and the injector harness is a common target. Wires can also chafe against the engine or other components, causing a short or open circuit.
   How to confirm: Visually inspect the wiring harness leading to the cylinder 5 injector. Look for any signs of chewing, chafing, or melted plastic. Check that the connector is securely plugged in and that the pins are clean and not corroded.
   Typical fix: Repair the damaged section of wire or replace the injector pigtail connector.
   Est. part cost: $15-$50
4. High-Pressure Fuel Pump (CP4) Failure (2019-2020 6.7L Cummins) ⚪ Low Probability The Bosch CP4 high-pressure fuel pump used on 2019-2020 models is known to fail, introducing metal debris into the entire fuel system. This can damage injectors and trigger circuit codes. This issue led to FCA recall Y78. 🎬 Watch: High pressure fuel pump replacement for the Y78 recall
   How to confirm: This is a severe failure. Diagnosis involves checking for metal debris in the fuel filter and fuel rail. Often accompanied by other codes like P0087 (Fuel Rail Pressure Too Low). This diagnosis is best left to a professional.
   Typical fix: Requires complete replacement of the high-pressure fuel system, including the pump, rails, lines, and all injectors. This is an extremely expensive repair covered under recall Y78.
   Est. part cost: $5000-$10000+

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is the least likely cause. The internal driver circuit for the injector can fail. All other possibilities, especially wiring and the injector itself, should be exhaustively ruled out before considering PCM replacement. One owner on RamForum.com suspected a PCM after extensive troubleshooting.
• Metal Shavings Shorting Injector Terminals (6.7L Cummins): On 2013-2018 models, small metal shavings created when tightening the injector terminal nuts can fall and create a short circuit against the injector solenoid body. After removing the valve cover, carefully inspect and clean the area around the injector terminals with a magnet before reassembly. Check for a short from each terminal to the engine block with a multimeter.

Diagnosis Steps

1. Use an OBD-II scanner to confirm P0205 and check for other related codes like P0305 or P2149.
2. Visually inspect the external wiring harness and connector for cylinder #5. Look for obvious damage, corrosion, or loose connections.
3. Perform a 'noid light' test. Disconnect the injector's electrical connector and plug in a noid light. Crank the engine. If the light flashes, the PCM and wiring to the connector are likely good, pointing towards a bad injector. If it does not flash or stays on constantly, there is a problem in the wiring or the PCM.
4. If the noid light test passes, test the injector itself. Disconnect the battery and the injector connector. Use a multimeter to measure the resistance across the two pins on the injector. Compare this reading to the manufacturer's specification (typically <1.0 ohm for Cummins, 12-16 ohms for Hemi).
5. For 6.7L Cummins engines, if other tests are inconclusive, remove the valve cover to inspect the internal injector wiring harness. This is a very common failure point. Check for brittle wires, loose connections, or damage, especially where the harness is integrated into the gasket.
6. While the valve cover is off, inspect for metal shavings around the injector terminals. When re-installing, torque the injector terminal nuts to a precise 8.8 in-lbs to avoid damage.
7. As a final confirmation, consider swapping the cylinder 5 injector with an adjacent injector (e.g., cylinder 6). Clear the codes and run the engine. If the fault code moves to the other cylinder (e.g., P0206), the injector is definitively bad. If P0205 returns, the problem is in the wiring or PCM.
8. If all wiring and the injector have been confirmed good, the final possibility is a failed injector driver in the PCM.

Parts You'll Likely Need

• Valve Cover Gasket with Integrated Injector Harness (6.7L Cummins) (OEM #5367847) — This is the most common failure point for P0205 on 2014-2018 6.7L Cummins engines, where the internal wiring becomes brittle from heat and vibration.
  Trusted brands: Cummins
  OEM price range: $200-$260
  Aftermarket price range: $90-$150
• Fuel Injector (6.7L Cummins) (OEM #68444791AA) — If the injector coil fails its resistance test or an injector swap confirms it's the faulty component, replacement is necessary. This is more common on Hemi engines but still occurs on the Cummins.
  Trusted brands: Mopar, Bosch
  OEM price range: $480-$700
  Aftermarket price range: $150-$400
• Fuel Injector (6.4L Hemi) — On the gasoline Hemi engines, the injector itself is a more common failure point than the associated wiring.
  Trusted brands: Mopar, Bosch, Standard Motor Products
  OEM price range: $90-$150
  Aftermarket price range: $40-$80

Related Codes That Often Appear With This One

• P0305 — P0305 means "Cylinder 5 Misfire Detected." Since P0205 indicates the injector circuit is failing, cylinder 5 isn't receiving the correct amount of fuel, which directly causes a misfire.
• P2149 — On common-rail Cummins engines, this code means "Fuel Injector Group B Supply Voltage Circuit/Open." Group B includes cylinders 4, 5, and 6. A short or open in the cylinder 5 circuit can cause the PCM to shut down the entire bank, triggering this code and making the truck run on only three cylinders.
• P0204, P0206 — Because cylinders 4, 5, and 6 are on the same bank ('B'), a short to ground or voltage on any one of these circuits can cause the PCM to set codes for all three injectors on that bank to protect the driver circuit.

Technical Service Bulletins (TSBs) & Recalls

• 18-099-22 REV. A: For 2019 models, links P0205 to potential high-pressure fuel pump failure and system contamination. Superseded by recall Y78.
• 18-053-14: For 2014 models, describes a PCM software update to make P0205 a two-trip fault to reduce nuisance warnings from intermittent connections.
• 18-099-22: An earlier version of the same bulletin with identical information regarding code P0205.

Platform-Specific Known Issues

• TSB 18-099-22 REV. A & Recall Y78 (2019-2020 6.7L Cummins): This TSB lists P0205 as a potential code resulting from a high-pressure fuel pump (CP4) failure, which contaminates the entire fuel system with metal debris. This TSB was superseded by recall Y78, indicating a serious, widespread issue.
• TSB 18-053-14 (2014 6.7L Cummins): For 2014 models, this TSB outlines a PCM software update that changes injector circuit faults (P0201-P0206) from a one-trip to a two-trip fault. This was done to reduce the frequency of the check engine light for minor, intermittent connection issues.
• Integrated Harness/Gasket Failure (6.7L Cummins): On 2014-2018 models, the injector wiring harness is integrated into the valve cover gasket. This design makes the harness prone to failure from heat and vibration and is the most common cause of P020x codes on these trucks.

Mechanic-Grade Diagnostic Values

• 6.7L Cummins Injector Coil Resistance — expected: < 1.0 Ohms. Failure: A reading of infinity (Open Loop) or over 1.0 Ohm indicates a failed solenoid.
• 6.4L Hemi Injector Coil Resistance — expected: 12-16 Ohms. Failure: A reading significantly outside this range, especially infinity (Open Loop) or near zero, indicates a failed injector.
• 6.7L Cummins Injector Pulse Width (Scan Tool Data) — expected: 0.5 - 0.9 ms at hot idle; 1.6 - 2.2 ms under moderate towing load.. Failure: A value of 0 indicates the PCM is not commanding the injector. Uneven rates between cylinders can indicate a failing injector.
• 6.7L Cummins Rail Pressure (for starting) — expected: Approximately 4,000 PSI. Failure: Failure to build sufficient rail pressure during cranking can prevent the engine from starting and may be related to injector or pump issues.
• Injector Circuit Continuity (Wiring Harness) — expected: < 0.5 Ohms. Failure: Higher resistance or an Open Loop (OL) reading indicates a break or corrosion in the wire between the PCM and the injector.

Scan Tool Commands That Help

• wiTECH (or equivalent professional scanner): Injector Kill Test / Cylinder Cutout Test — This bidirectional command allows a technician to disable individual injectors one at a time while the engine is running. If disabling cylinder 5 causes no change in engine idle, it confirms that cylinder was not contributing, strongly pointing to a problem in that circuit or with that injector.
• wiTECH (or equivalent professional scanner): View Freeze Frame Data — This should be one of the first steps. It shows the engine conditions (speed, load, temperature) at the exact moment the P0205 code was set, which can provide clues as to whether the fault is intermittent or occurs under specific loads.

Wiring & Ground Locations

• Injector #5 Control Circuit (6.7L Cummins) — This circuit runs from a pin on the Powertrain Control Module (PCM) C2 connector, through the main engine harness, to the valve cover pass-through connector, and then through the internal valve cover gasket harness to the injector.. This entire path must be tested for continuity, shorts to ground, and shorts to power. The most common failure points are within the valve cover gasket harness and at the pass-through connector.
• Injector #5 Control Circuit (6.4L Hemi) — The (K38) Injector Control No. 5 circuit runs from the PCM to the injector. Cylinder #5 is the third cylinder back from the front on the driver's side.. A service manual procedure for a similar engine involves disconnecting the C2 PCM harness connector and measuring resistance to check the circuit, indicating the control wire is in that connector.
• Harness Chafing Point (Cummins) — A known issue on some platforms involves the main engine harness chafing where it crosses over the alternator.. This can cause an intermittent short to ground for one or more injector circuits, leading to codes like P0205 and P2149.

Real Owner Repair Stories

• RamForum.com user 'Tr3y' (Ram 1500 (year not specified, but Hemi engine implied)) — P0205 and P0305, injector stuck open and dumping fuel.
  ❌ Tried (didn't work) Load tested all wiring for injector #5 (tested good)., Tested for short to ground on both wires (tested good)., Tested for short to power on both wires (tested good)., Swapped injectors multiple times (the problem did not move to another cylinder)., Cleaned injectors., Checked all fuses.
  ✅ What actually fixed it The user suspected a corrupted PCM was the only remaining possibility after exhaustively testing all wiring and swapping injectors without the fault moving. The thread ends before final confirmation, but points to PCM failure when all other common causes are eliminated.

OEM Part Supersession History

• 5264950, 3975641 → 5367847 — The part was updated by Cummins for improved design, better oil resistance, and enhanced electrical durability.
• 68444791AA → R8444791AA, R8504672AA — Part numbers are often superseded with remanufactured (R-prefix) or updated versions. 68444791AA is the original equipment number, while others may be service replacements.
  Heads up: These parts are for the 2019+ trucks with the CP4 pump and are not interchangeable with the 2014-2018 injectors.

Model Year Variations Within This Range

• 2014-2018: These model years primarily use solenoid-style injectors and a CP3 high-pressure fuel pump. The most common cause for P0205 is the under-valve-cover wiring harness integrated into the gasket (P/N 5367847).
• 2019-2020: These models transitioned to a Bosch CP4 high-pressure fuel pump and may use faster piezoelectric injectors. They are subject to recall Y78 for CP4 pump failure, which can cause P0205 by sending metal debris through the fuel system, damaging the injectors. The injector part number is different (e.g., 68444791AA).