P0201 on 2014-2020 Ram 2500: Injector 1 Circuit/Open Causes and Fixes

What's Unique About the 2014-2020 Ram 2500

On the Ram 2500 with the 6.7L Cummins engine, a very common failure point is the injector wiring harness that is integrated into the valve cover gasket. This harness is prone to degradation from intense heat and vibration, leading to an open circuit. For Hemi gasoline engines, the issue is more typically the injector itself or the external connector. Ram also issued a software update under TSB #18-045-15 REV A to change the P0201 fault from a sensitive 'one-trip' fault to a more reliable 'two-trip' fault, which requires the PCM to see the error on two consecutive drives before turning on the check engine light.

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 fourth generation (2014-2018) and the start of the fifth generation (2019-2020) Ram 2500. While the P0201 code's meaning is consistent, 2019-2020 Cummins models use a Bosch CP4.2 high-pressure fuel pump that is prone to catastrophic failure and can cause multiple injector codes when it fails. This issue led to recall Y78 (NHTSA 21V880000). The injectors for 2019+ models were also changed to operate at higher pressures (up to 200 MPa) and have a different design than the 2014-2018 injectors.

Symptoms You May Notice

• Check Engine Light is on
• Rough, unstable, or stumbling idle
• Engine misfire, sometimes felt as a shake or shudder
• Reduced engine power and acceleration ('limp mode')
• Poor fuel economy
• Raw fuel smell from the exhaust
• White smoke from exhaust on Cummins models

Most Likely Causes

1. Faulty Injector Wiring Harness (6.7L Cummins) 🔴 High Probability The harness is integrated into the valve cover gasket and is constantly exposed to intense heat, vibration, and oil, causing wires to become brittle and break, especially at the connector terminals.
   How to confirm: After removing the valve cover, visually inspect the harness for cracks, chafing, or burnt pins. Perform a continuity test on the wires from the injector to the main pass-through connector. A 'wiggle test' on the harness while the engine is running may cause a change in idle, indicating an intermittent open.
   Typical fix: Replace the valve cover gasket which includes the integrated injector harness. Torque the injector terminal nuts to the correct specification (8.8 in-lbs) during reassembly.
   Est. part cost: $100-$200
2. Failed Fuel Injector #1 🔴 High Probability High-pressure injectors operate under extreme stress and the internal solenoid coil can burn out over time. This is the most common cause on 6.4L Hemi engines. On Cummins engines, fuel contamination can also lead to premature failure.
   How to confirm: Swap the #1 injector with another cylinder (e.g., #2). If the code changes to P0202, the injector is bad. Alternatively, test the injector's resistance with a multimeter. A Cummins injector should be <1 Ohm, while a Hemi should be 11-15 Ohms. An 'OL' or infinite reading means the injector coil is open and has failed.
   Typical fix: Replace the faulty fuel injector. On Cummins engines, the new injector's IQA code must be programmed into the PCM for proper operation.
   Est. part cost: $150-$700
3. Poor Connection at Injector or PCM 🟡 Medium Probability Vibration can cause connectors to loosen or pins to corrode over time. On Cummins engines, the terminal nuts on top of the injector can loosen, causing an open circuit. On Hemi engines, pins can sometimes get bent inside the main PCM connector.
   How to confirm: Inspect the electrical connector at the injector and the PCM. Check for loose, corroded, or bent pins. On Cummins, check that the injector terminal nuts are torqued to specification (8.8 in-lbs).
   Typical fix: Clean the connector pins with electrical contact cleaner and apply dielectric grease. Tighten any loose connections. Carefully straighten any bent PCM pins.
   Est. part cost: $5-$20

Rare But Worth Checking

• Failed Powertrain Control Module (PCM) Injector Driver: This is very rare and should only be considered after all wiring and the injector itself have been proven to be good. A failure here often sets codes for an entire bank of injectors (e.g., P0201, P0202, P0203). One owner on a forum reported a bent pin inside the PCM connector, which is a much more likely scenario than a failed driver.

Diagnosis Steps

1. Check for other DTCs. If multiple injector codes (P0201-P0206) and fuel pressure codes (P0087) are present on a 2019-2020 model, investigate the high-pressure fuel system per TSB #18-099-22 REV. A for CP4 pump failure.
2. If only P0201 is present, locate cylinder #1 (front of the engine on Cummins, front driver's side on Hemi).
3. Visually inspect the wiring harness leading to the injector for obvious damage, chafing, or corrosion.
4. Use a noid light to test the electrical connector for injector #1. Crank the engine. A flashing light indicates the PCM and wiring are sending a signal, pointing to a bad injector. No light suggests a wiring or PCM problem.
5. Disconnect the battery. Test the resistance of the fuel injector with a multimeter. Compare the reading to the specification (<1 Ohm for Cummins, 11-15 Ohms for Hemi). An 'OL' or infinite reading means the injector coil is open and has failed.
6. If the injector tests good, check for continuity on the two wires between the PCM connector and the injector connector. Also check each wire for a short to ground or a short to power.
7. As a definitive test, swap the #1 fuel injector with the #2 fuel injector. Clear the codes and run the engine. If the code changes to P0202, the injector is faulty. If P0201 returns, the problem is in the wiring or PCM.

Parts You'll Likely Need

• Fuel Injector (6.7L Cummins, 2014-2018 Pickup) (OEM #68210105AA (Mopar), 0986435621 (Bosch Reman)) — The internal solenoid coil of the injector can fail. Fuel contamination is a common cause of premature failure.
  Trusted brands: Bosch, Mopar
  OEM price range: $450-$700
  Aftermarket price range: $250-$500
• Fuel Injector (6.4L Hemi) (OEM #4627479AB) — The internal solenoid coil of the injector is the most common failure item for this code on Hemi engines.
  Trusted brands: Mopar, TRQ
  OEM price range: $120-$170
  Aftermarket price range: $60-$100
• Valve Cover Gasket with Integrated Injector Harness (6.7L Cummins) (OEM #5264950 (superseded by 68460979AA)) — This is the most common cause of P0201 on the 6.7L Cummins engine, as the wiring becomes brittle and fails from heat and vibration.
  Trusted brands: Mopar, Cummins
  OEM price range: $150-$250
  Aftermarket price range: $80-$150
• Fuel Injector Connector Pigtail — If the plastic connector or its terminal pins are damaged, replacing just the pigtail is a cost-effective repair.
  Trusted brands: Dorman, Mopar
  OEM price range: $30-$50
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• P0301 — This code means 'Cylinder 1 Misfire Detected'. Since P0201 prevents fuel from being injected into cylinder 1, a misfire is the direct result.
• P0202, P0203 — On 6.7L Cummins engines, injectors are grouped in banks (1-3 and 4-6). A significant electrical short in one injector circuit can cause the PCM to shut down the entire bank to protect the internal driver, setting codes for all three injectors in that bank.
• P0087 — As noted in TSB #18-099-22 REV. A, this code for 'Fuel Rail Pressure Too Low' can appear with P0201, especially on 2019-2020 models, indicating a larger problem like a failing high-pressure CP4.2 fuel pump.
• P2146 — This code means 'Fuel Injector Group A Supply Voltage Circuit/Open' and points to a fault in the power supply for injectors 1, 2, and 3. It often appears with P0201, P0202, and P0203 and strongly suggests a wiring fault common to all three, such as the under-valve-cover harness.

Technical Service Bulletins (TSBs) & Recalls

• 18-099-22 REV. A: Links P0201-P0206 codes to potential fuel pump failure and system contamination on 2019-2020 models.
• 18-045-15 REV A: Details a software update changing P0201-P0206 from a one-trip to a two-trip fault to reduce nuisance codes.
• 18-099-22: Original bulletin linking injector circuit codes to fuel pressure issues.
• 18-045-15: Original bulletin for the one-trip to two-trip fault software update.
• 1805421: Another bulletin noting the association between P0201 and fuel pressure codes P0087 and P008A.

Platform-Specific Known Issues

• A software update was issued under TSB #18-045-15 REV A to change the P0201 fault from a one-trip to a two-trip fault, reducing false check engine lights from intermittent connection issues.
• TSB #18-099-22 REV. A notes that on 2019-2020 models, P0201 can appear with other injector and fuel pressure codes (like P0087) as a result of a catastrophic high-pressure fuel pump failure. This issue was also addressed by recall Y78.
• On 6.7L Cummins engines, the injectors are grouped into two banks (1-3 and 4-6). A short circuit in one injector can cause the PCM to disable the entire bank as a protective measure, resulting in multiple codes (P0201, P0202, P0203) and the related code P2146.

Mechanic-Grade Diagnostic Values

• 6.7L Cummins Fuel Injector Resistance — expected: 0 to 1.0 Ohm. Failure: An infinite reading (OL) or high resistance indicates a failed injector coil.
• 6.4L Hemi Fuel Injector Resistance — expected: 11-15 Ohms at room temperature.. Failure: A reading significantly outside this range or an open loop (OL) reading.
• 6.7L Cummins Injector Circuit Short to Ground — expected: Greater than 10k Ohms.. Failure: Resistance below 10k Ohms indicates a short to ground in the circuit.
• 6.7L Cummins Injector Terminal Nut Torque — expected: 8.8 in-lbs (0.99 Nm). Failure: Loose nuts cause an open circuit; over-tightening can damage the injector.
• 6.7L Cummins Fuel Rail Pressure (Cranking) — expected: Approximately 4,000 PSI. Failure: Failure to build sufficient rail pressure during cranking can prevent starting and may indicate injector leakage or pump issues.
• 6.7L Cummins Fuel Rail Pressure Sensor Voltage (KOEO) — expected: Approximately 0.5 Volts. Failure: Incorrect voltage at Key On, Engine Off may indicate a faulty sensor or wiring issue.
• Injector Pulse Width (at idle) — expected: Approximately 2.5 milliseconds (varies by tune and conditions). Failure: Significantly longer pulse width on other cylinders may indicate the PCM is trying to compensate for a dead cylinder.

Scan Tool Commands That Help

• wiTECH, DRBIII, or equivalent professional scan tool: Injector Kill Test / Cylinder Cutout Test — Used to isolate a misfiring cylinder. When the scan tool deactivates a healthy injector, the engine idle will noticeably worsen. If deactivating an injector causes no change in idle, that cylinder is the one with the problem. This helps confirm which cylinder is at fault before disassembly.
• wiTECH or equivalent: Fuel Pressure Override Test — This test commands maximum rail pressure (e.g., 26,000+ PSI) to check for leaks in the high-pressure system. It's used to diagnose excessive injector return flow, which can cause hard starts and low power, sometimes in conjunction with injector codes.
• wiTECH or equivalent: Program IQA Codes / Injector Flow Programming — This is required after replacing a fuel injector on a 6.7L Cummins engine. Each new injector has a specific flow rate code (IQA code) that must be entered into the PCM to ensure proper fueling, smooth idle, and emissions compliance.

Wiring & Ground Locations

• PCM Connector C1 (6.7L Cummins) — The main engine computer (PCM/ECM) is located on the driver's side of the engine block.. This connector contains the driver circuits for the injectors. For Injector #1, the specific pins are K11 (High Side Driver) and K611 (Low Side Driver). Testing for continuity and shorts should be done at these pins.
• Valve Cover Pass-Through Connector (6.7L Cummins) — The large, rectangular electrical connector on the valve cover.. This is the junction between the main engine harness and the internal harness that is integrated into the valve cover gasket. It's a key point for testing to determine if the fault is in the external harness or the failure-prone internal harness.
• Main Chassis/Engine Grounds — Key grounds are located from the battery negative terminal to the chassis and engine block. A specific ground point is often found on the sheet metal below the driver's side battery.. While a bad ground typically causes multiple, widespread electrical issues rather than a single injector code, poor grounding can lead to erratic PCM behavior and voltage drops that could potentially trigger false codes. Ensuring main grounds are clean and tight is a crucial foundational step.

Real Owner Repair Stories

• cumminsforum.com user (2014 Ram 2500 6.7L Cummins) — Sudden rough running, check engine light on, multiple injector codes (P0201, P0202, P0203) and a group fault code (P2146).
  ❌ Tried (didn't work) Initial diagnosis pointed to a single bad injector, but the presence of multiple codes for the entire bank suggested a common wiring issue.
  ✅ What actually fixed it The owner replaced the valve cover gasket with the integrated injector harness (Mopar part #5264950). This resolved all codes and the rough running, confirming the internal harness had failed and shorted, causing the PCM to shut down the entire injector bank.
• Reddit user r/Cummins (2021 Ram 4500 6.7L Cummins) — User ran out of fuel, which triggered a P0201 code that was stored as 'constant' even after the check engine light went away after repriming the system.
  ❌ Tried (didn't work) The code could not be cleared with the user's scan tool.
  ✅ What actually fixed it The dealer advised that as long as the check engine light is off, the code is a stored historical fault and not active. The suggested fix was to disconnect the batteries to perform a hard reset of the modules, which would clear the stored code.

OEM Part Supersession History

• 5264950 → 68460979AA (Mopar), 5367847 (Cummins) — The original valve cover gasket with integrated harness was prone to failure from heat and vibration. The updated part uses improved materials for better durability.
• 68444790AA (High Output) → 68568034AA — Standard part revision and updates by the manufacturer for 2019+ High Output engines.
  Heads up: Injectors for Standard Output (SO) and High Output (HO) 2019+ engines are different and not interchangeable.
• 68444791AA (Standard Output) → 68568033AA — Standard part revision and updates by the manufacturer for 2019+ Standard Output engines.
  Heads up: Injectors for Standard Output (SO) and High Output (HO) 2019+ engines are different and not interchangeable.

Model Year Variations Within This Range

• 2014-2018: These models use a Bosch CP3 high-pressure fuel pump and solenoid-style injectors. The most common cause for P0201 is the under-valve-cover wiring harness or the injector itself.
• 2019-2020: These models switched to a Bosch CP4.2 high-pressure fuel pump and different injectors designed for higher pressure (up to 200 MPa). The CP4.2 pump is known for a failure mode that can send debris through the fuel system, causing P0201 along with other injector and fuel pressure codes (P0087), as noted in TSB #18-099-22 REV. A. Injectors are also specific to Standard Output (SO) vs. High Output (HO) engine variants and are not interchangeable with earlier years.