P0202 on 2014-2020 Ram 2500: Injector 2 Circuit/Open Causes & Fixes

What's Unique About the 2014-2020 Ram 2500

On the 6.7L Cummins diesel engine, the wiring harness for the injectors is a known weak point. It is integrated into the valve cover gasket, where constant exposure to heat, oil, and vibration can cause wires to become brittle and break, making a wiring issue a very common cause for P0202. For gasoline HEMI engines, a Technical Service Bulletin (TSB 18-099-22 REV. A) indicates that P0202 and other injector circuit codes can be set as a result of low fuel rail pressure, which might point to a failing fuel pump rather than an injector-specific problem. For 2019-2020 Cummins models, this same TSB, which was superseded by recall Y78, warns that a failing CP4 high-pressure fuel pump can send debris through the system, causing injector codes.

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). The meaning of P0202 is the same, but the 2019-2020 models with the 6.7L Cummins may have a different high-pressure fuel pump (Bosch CP4) which was subject to recall Y78 (NHTSA 21V-880) for failures that could cause injector-related codes.

Symptoms You May Notice

• Check Engine Light is on
• Rough or shaking idle
• Engine misfire or stumbling
• Loss of power and poor acceleration
• Decreased fuel economy
• Engine will not start
• White smoke at idle (may be hidden by DPF on newer trucks)

Most Likely Causes

1. Faulty Injector Wiring Harness (especially 6.7L Cummins) 🔴 High Probability → Shop Engine Wiring Harness On the 6.7L Cummins, the injector harness is integrated with the valve cover gasket, exposing it to intense heat, oil, and vibration which leads to wire failure and fretting corrosion at the connector pins.
   How to confirm: Visually inspect the wiring harness for chafing, melting, or breaks, especially where it passes through the valve cover. Perform a continuity test on the wires from the PCM to the injector connector; resistance should be less than 5 ohms. A 'wiggle test' on the harness while the engine is running may change the misfire. Check the tightness of the two small terminal nuts on top of the injector; they are delicate and should be torqued to 8.8-13 in-lbs.
   Typical fix: Replace the valve cover gasket/harness assembly. In some cases, a damaged connector pigtail can be replaced.
   Est. part cost: $90-$300
2. Failed Fuel Injector #2 🟡 Medium Probability → Shop Fuel Injector The internal electronic coil of the injector can fail, creating an open circuit. This is a common failure for any high-mileage vehicle. On 2019-2020 Cummins models, debris from a failing CP4 fuel pump can also damage injectors.
   How to confirm: Test the injector's internal resistance with a multimeter. For a Cummins injector, it should be less than 1.0 Ohm but greater than 0. For a HEMI injector, it should be in the 12-15 Ohm range. An 'OL' (Open Loop) reading indicates a failed injector. A more definitive test is to swap the #2 injector with an adjacent one (e.g., #1 or #3). Clear the codes and run the engine. If the code changes to P0201 or P0203, the injector is bad. If P0202 returns, the problem is in the wiring.
   Typical fix: Replace the faulty fuel injector. It is best practice to also replace the high-pressure connector tube 🎬 Watch this step-by-step guide for replacing a Cummins 6.7 injector. on Cummins engines to prevent leaks.
   Est. part cost: $150-$650
3. Damaged External Wiring or Connector 🟡 Medium Probability Engine vibration and heat can damage the external portion of the harness or the plastic connector at the injector, causing a poor connection. Rodent damage is also a possibility.
   How to confirm: Visually inspect the connector for broken tabs, corrosion, or backed-out pins. Wiggle the connector while the engine is idling to see if it causes the misfire to change. Check for continuity from the PCM connector to the injector connector.
   Typical fix: Repair the damaged wire or replace the connector pigtail.
   Est. part cost: $15-$50
4. Low Fuel Pressure / Failing Fuel Pump (Gasoline & Diesel) ⚪ Low Probability As noted in TSB 18-099-22 REV. A, low fuel pressure from a weak fuel pump can, on these specific vehicles, trigger injector circuit codes. For 2019-2020 Cummins, this is often due to the recalled CP4 high-pressure fuel pump failing and contaminating the system.
   How to confirm: Connect a fuel pressure gauge and verify that the fuel pressure is within the manufacturer's specified range. On 2019-2020 Cummins, check the fuel filter housing for fine, silver, glitter-like metal shavings, which indicates HPFP failure.
   Typical fix: Diagnose and repair the source of the low fuel pressure. For CP4 failure, this involves replacing the entire high-pressure fuel system (pump, rails, lines, injectors) and cleaning the tank.
   Est. part cost: $200-$10,000+

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is rare and should only be considered after the injector and all wiring have been thoroughly tested and confirmed to be good. A PCM failure may set codes for an entire bank of injectors (e.g., P0201, P0202, P0203).
• Blown Fuel Injector Fuse: → Shop Fuel Injector While less common for a single injector code, a dedicated fuse for the injector bank could be blown. One YouTube video for 2013-2018 Rams points to a 25A fuse in the under-hood fuse box as a potential culprit for multiple injector codes.

Diagnosis Steps

1. Read the codes with an OBD-II scanner and note any other codes present, especially P0302, P0087, or other injector codes.
2. Visually inspect the wiring harness and connector for cylinder #2 (second from the front) for any obvious signs of damage, melting, or corrosion.
3. Perform a 'wiggle test' on the injector connector and nearby harness with the engine running to see if it affects the idle.
4. Use a multimeter to test the resistance of the #2 fuel injector. Disconnect it and measure across the two pins. Compare the reading to the manufacturer's specification (typically <1 Ohm for Cummins, 12-15 Ohms for HEMI). An 'OL' (Open Loop) reading indicates a failed injector.
5. If injector resistance is good, test the wiring. Use a noid light to check for a signal pulse at the injector connector 🎬 See this video for common causes and fixes for P0202. while cranking the engine. A flashing light means the PCM and wiring are likely good. No light points to a wiring or PCM problem.
6. Perform a continuity test on both wires running from the PCM connector to the injector connector to check for breaks. Resistance should be under 5 ohms. Also, check each wire for a short to ground or a short to voltage.
7. If accessible, swap the #2 fuel injector with an adjacent one (like #1). Clear the codes and run the engine. If the code moves to P0201, the injector is faulty. If P0202 returns, the wiring or PCM is the issue.
8. For 6.7L Cummins: Remove the valve cover to inspect the internal harness. Check continuity from the external pass-through connector to the pigtail for the #2 injector. Check the torque on the injector terminal nuts (8.8-13 in-lbs).
9. If all else fails, the issue may be with the injector driver circuit inside the PCM, which requires professional diagnosis.

Parts You'll Likely Need

• Valve Cover Gasket with Injector Harness (6.7L Cummins) (OEM #5367847, 68441885AA, 5264950) — On the 6.7L Cummins, this integrated assembly is the most common point of failure for this code due to heat and vibration.

Related Codes That Often Appear With This One

• P0302 — This code means 'Cylinder 2 Misfire Detected'. Since P0202 indicates the injector isn't firing correctly, a misfire on that cylinder is a direct and expected consequence.
• P0201, P0203, etc. — If multiple injector codes are present, it points towards a larger issue. On Cummins, a short in one injector circuit can cause the PCM to shut down the entire bank (1-3 or 4-6) to protect the driver, setting codes for all three.
• P0087 — This code for 'Fuel Rail Pressure Too Low' can appear with P0202, as noted in TSB 18-099-22 REV. A. This combination strongly suggests a systemic fuel delivery problem, like a failing high-pressure fuel pump, rather than an isolated injector issue.
• P2146 — On Cummins engines, this code ('Fuel Injector Group 'A' Supply Voltage Circuit/Open') can be triggered by a fault in the cylinder 2 circuit, as the PCM monitors injectors in banks (1-3 and 4-6). Fixing the P0202 cause will often clear P2146.

Technical Service Bulletins (TSBs) & Recalls

• 18-099-22 REV. A
• 18-099-22
• 18-054-21
• 18-028-16 REV. A

Platform-Specific Known Issues

• Owner Experience: Chasing an Intermittent P0202 on a 5.7L HEMI: A user on RamForum.com with a 2003 Ram 1500 (analogous issue) reported a P0202 code that would only appear after the truck was warm and driven, not at idle. The owner first replaced the injector, then swapped it with another cylinder, but the P0202 code remained on cylinder 2. They verified good continuity on the wiring and a correct signal with a noid light while the engine was cold. The problem was eventually traced to a break in the signal wire within the main engine harness that would only open up and lose connection when the engine bay reached full operating temperature. This highlights how a static test in a cool engine bay can be misleading, and intermittent faults often point to wiring issues that change with heat and vibration.

Mechanic-Grade Diagnostic Values

• 6.7L Cummins Injector Solenoid Resistance — expected: Less than 1.0 Ohm, but greater than 0 Ohms. Failure: A reading of 'OL' (Open Loop) or infinite resistance.
• 6.7L Cummins Injector Terminal Nut Torque — expected: 8.8-11 in-lbs. Failure: Loose nuts can cause an open circuit; over-tightening can damage the injector.
• 6.7L Cummins Injector Wiring Harness Continuity — expected: Less than 10 Ohms. Failure: A reading higher than 10 Ohms indicates excessive resistance or an open in the harness.
• 6.7L Cummins Fuel Rail Pressure (Cranking) — expected: Approximately 4,000 PSI or higher. Failure: Significantly lower pressure prevents the engine from starting and can indicate a larger fuel system issue.
• 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 driver circuit.
• 5.7L/6.4L HEMI Injector Resistance — expected: Approximately 12-15 Ohms. Failure: A reading significantly different from other injectors, or 'OL' (Open Loop).

Scan Tool Commands That Help

• wiTECH or equivalent professional scanner: Injector Kill Test / Cylinder Cutout Test — This function allows the technician to disable one injector at a time while the engine is running. If disabling cylinder #2 causes no change in idle roughness, it confirms that cylinder was not contributing, validating the fault is in the #2 injector circuit. This is a primary step to confirm the location of the misfire before testing components.
• wiTECH: Fuel Pressure Override Test — This test commands the fuel system to its maximum pressure (around 26,000 PSI) while the engine is running at a set RPM. It's used by advanced technicians to test for injector leakage by measuring return flow, which can help differentiate a mechanical injector issue from a purely electrical one.

Wiring & Ground Locations

• Cylinder 2 Injector Control Circuit (PCM) — At the PCM C1 harness connector, this corresponds to the (K12) Fuel Injector 2 High Side Driver circuit and the (K612) Fuel Injector 2 Low Side Driver circuit.. These are the specific circuits and pin designations a technician needs to test for continuity, shorts to ground, or shorts to voltage directly from the PCM, definitively isolating the problem to the wiring, injector, or PCM itself.
• G101 / G102 — G101 is on the left front of the engine, related to the battery ground. G102 is the battery ground on the left front of the chassis.. A poor engine or chassis ground can cause floating voltages and unpredictable electrical behavior across multiple systems, including the injector driver circuits in the PCM. Verifying these main grounds are clean and tight is a crucial early step in diagnosing any electrical fault.
• G106 — Located on the left rear of the engine.. This is a primary engine block ground. A loose or corroded connection here can directly impact the electrical reference for sensors and actuators mounted on the engine, potentially causing the PCM to misinterpret data from the injector circuits.
• F25 Fuse (Potentially) — In the under-hood main engine fuse box.. A YouTube video for 2013-2018 Ram trucks identifies a 25A fuse that may protect the fuel injector circuits. If multiple injector codes (P0201, P0202, P0203, etc.) appear simultaneously, checking this fuse is a quick and easy first step before diagnosing a more complex wiring or PCM issue.

Real Owner Repair Stories

• cumminsforum.com user (2014 Ram 2500 6.7L Cummins) — Rough running and check engine light with codes P0201, P0202, P0203, and P2146.
  ❌ Tried (didn't work) Diagnosing individual injectors.
  ✅ What actually fixed it The owner replaced the entire valve cover gasket which has the injector harness integrated into it (Mopar P/N 5264950). This single part replacement resolved all four codes, confirming the common failure of the under-cover harness causing a bank-wide fault.

OEM Part Supersession History

• 3975641, 5264950 → Mopar 5367847 — Design revision to improve durability and resistance to heat/vibration.
  Heads up: This is the part number for the Valve Cover Gasket with Integrated Injector Harness for 6.7L Cummins engines. The latest revision (5367847) is recommended for all applicable years for the most updated design.

Model Year Variations Within This Range

• 2019-2020: Models in this range with the 6.7L Cummins may be equipped with the Bosch CP4.2 high-pressure fuel pump, which was subject to a major recall (Y78 / NHTSA 21V-880). A failure of this pump can cause metal debris to contaminate the entire fuel system, leading to multiple injector codes (like P0202) and a P0087 (Fuel Rail Pressure Too Low) code. Diagnosis must include checking the fuel filter for metal shavings before replacing injectors.