P1404 on 2019-2024 Ram 2500 6.4L V8: EGR Valve Causes and Fixes

What's Unique About the 2019-2024 Ram 2500

On the 6.4L Hemi V8 (engine code ESB) in this generation of Ram trucks, the P1404 code is strongly linked to a direct failure of the EGR valve assembly itself, rather than just carbon buildup. Multiple Technical Service Bulletins (TSBs) have been issued by the manufacturer for this exact code, citing "Internal EGR Valve Distortion" as the cause and calling for a complete replacement of the valve. This suggests a potential design or manufacturing flaw in the part, making replacement a much more reliable fix than cleaning. Forum discussions among owners confirm that replacing the valve is the standard, effective repair.

Symptoms You May Notice

• Check Engine Light (Malfunction Indicator Lamp) is on
• Engine tugging or hesitation, especially at low speeds.
• Unstable or rough idle.
• Engine knocking or pinging noises.
• Reduced fuel efficiency.
• Failed emissions test
• Abrupt gear engagement during Power Take-Off (PTO) operation.

Most Likely Causes

1. Faulty EGR Valve Assembly 🔴 High Probability Multiple manufacturer TSBs (including #09-007-25) cite "Internal EGR Valve Distortion" as the direct cause for this code on the 6.4L Hemi, indicating a common part failure. This is widely corroborated in owner forums as the primary fix.
   How to confirm: Use an OBD-II scanner to monitor the EGR commanded position versus the actual position. At idle, 'EGR Commanded' should be 0% and 'EGR Actual' should be at or very near its learned closed position voltage (typically under 1.0V). If the actual position does not return to this baseline when commanded closed, the valve's internal sensor or mechanism has failed.
   Typical fix: Replace the entire EGR valve assembly with a new one. This is the specific repair called for in TSB #09-007-25.
   Est. part cost: $170-$270
2. PCM Software Issue 🟡 Medium Probability TSB #18-004-26 and #18-088-22 (superseded) explicitly state that P1404 can be set due to a software glitch, causing symptoms like engine tugging or unstable idle. This is a known issue that requires a dealer-level software update.
   How to confirm: A dealership or qualified shop must check the vehicle's VIN against FCA's service database (DealerCONNECT) to see if a PCM software update for TSBs like 18-004-26 is applicable and outstanding.
   Typical fix: Reprogram the Powertrain Control Module (PCM) with the latest software using the wiTECH scan tool.
   Est. part cost: $0 if covered by a service campaign or warranty, otherwise dealer labor rates apply (typically 0.5-1.0 hours).
3. Carbon Buildup in EGR Passages ⚪ Low Probability While all EGR systems are susceptible to carbon (soot) buildup, on this specific platform it is a less frequent cause of P1404 than outright valve failure. However, it can still physically prevent the valve from seating correctly.
   How to confirm: Remove the EGR valve and visually inspect the valve pintle and the intake manifold passages for heavy, chunky carbon deposits that could restrict movement.
   Typical fix: Clean the EGR valve and passages with a wire brush and carburetor cleaner. However, due to the high rate of internal valve failure on this platform, replacement is often a more permanent solution.
   Est. part cost: $10-$20 for cleaning supplies

Rare But Worth Checking

• Damaged Wiring or Connector: While less common than valve failure, the wiring harness to the EGR valve can become damaged from engine heat and vibration. A quick visual inspection for frayed wires, melted insulation, or loose pins in the connector is worthwhile before replacing parts.

Diagnosis Steps

1. Connect an OBD-II scanner to confirm P1404 is the primary code. Check for other codes like P0456 or P2457, which may be related per TSBs.
2. Check with a dealer if the vehicle's VIN has any open software updates (recalls/TSBs), specifically referencing TSB #18-004-26 or similar PCM flashes, before proceeding with hardware replacement.
3. Use the scanner's live data function to observe 'EGR Commanded Position' and 'EGR Actual Position'. Command the EGR valve closed (it should be at idle) and verify if the actual position reads above the learned closed value (typically > 5-10%).
4. If the position is incorrect, inspect the wiring harness and connector going to the EGR valve for any signs of damage, melting, or corrosion.
5. If wiring is intact, remove the EGR valve from the engine. It is located on the front of the intake manifold.
6. Inspect the valve and its corresponding port on the intake manifold for heavy carbon buildup that could be preventing it from closing.
7. If significant carbon is present, you can attempt to clean it. However, given the TSBs for this vehicle citing 'Internal EGR Valve Distortion', the valve's internal sensor is the most likely failure point.
8. The most reliable repair is to replace the EGR valve assembly and the associated gaskets.
9. After installation, clear the trouble codes with the scanner and perform a test drive to ensure the code does not return.

Parts You'll Likely Need

• Exhaust Gas Recirculation (EGR) Valve (OEM #4627465AG) — This is the most common failure part for code P1404 on this engine, as confirmed by multiple manufacturer service bulletins that cite internal valve failure. This part number supersedes previous versions 4627465AC, 4627465AD, 4627465AE, and 4627465AF.
  Trusted brands: Mopar, Standard Motor Products, Wells
  OEM price range: $240-$270
  Aftermarket price range: $170-$190
• EGR Mounting Gasket (OEM #04627541AC) — The gasket provides a critical seal and should always be replaced when the EGR valve is removed to prevent exhaust leaks. It is often included with a new EGR valve.
  Trusted brands: Mopar, Fel-Pro
  OEM price range: $10-$15
  Aftermarket price range: $5-$10

Related Codes That Often Appear With This One

• P0456 — A manufacturer TSB (#1807123) notes that P1404 can appear alongside P0456 (EVAP System Small Leak), sometimes due to related PCM software issues that require a reflash.
• P2457 — TSB #18-088-22 states that P1404 can be erroneously set when P2457 (EGR Cooling System Performance) is the primary fault. The diagnostic procedure should focus on the P2457 first.

Technical Service Bulletins (TSBs) & Recalls

• 18-004-26: Links P1404 to engine tugging and unstable idle, recommends PCM software update.
• 1807123: Mentions P1404 can be set with P0456.
• 09-007-25: States the fix for P1404 is replacing the EGR valve due to internal distortion.
• 18-088-22: Notes P1404 can be a 'ghost code' triggered by P2457.

Platform-Specific Known Issues

• TSB #09-007-25: Explicitly states that for P1404, the bulletin involves replacing the EGR valve due to 'Internal EGR Valve Distortion'.
• TSB #18-004-26: Connects P1404 to customer complaints of 'Engine tugging' and 'Unstable idle' and identifies the cause as a PCM software issue requiring a reflash.
• TSB #1807123: Notes that P1404 may be set along with P0456 for an EVAP system leak, often related to software.
• TSB #18-088-22: Informs technicians that P1404 can be set erroneously when the real fault is P2457 (EGR Cooling System Performance).

Mechanic-Grade Diagnostic Values

• EGR Position Sensor Signal Voltage (at idle, closed) — expected: ~0.7V. Failure: Voltage significantly higher than the learned closed position value, indicating the valve is not fully seated.
• EGR Position Sensor Signal Voltage (fully open) — expected: ~4.5V. Failure: Voltage does not reach this level when commanded open, or is stuck high when commanded closed.
• Sensor Ground Circuit Voltage Drop — expected: < 50 mV. Failure: Voltage higher than 50 mV indicates high resistance in the ground circuit, which can skew sensor readings.
• EGR Solenoid Coil Resistance — expected: 4-12 Ohms (general range). Failure: Resistance is infinite (open circuit) or near zero (short circuit).

Scan Tool Commands That Help

• wiTECH or equivalent professional scanner: EGR Valve Actuator Test / Duty Cycle Control — To functionally test the EGR valve by commanding it to open and close. This verifies if the solenoid is responding to PCM commands and if the engine stumbles or stalls when the valve is opened at idle, confirming the passages are clear.
• wiTECH or equivalent professional scanner: EGR System Reset / Relearn — After replacing the EGR valve. Some vehicles require the PCM's learned values for the EGR closed position to be reset. Failure to do so can cause the P1404 code to return even with a new part. In some cases, disconnecting the battery for a period may also force this reset.
• wiTECH or equivalent professional scanner: Check for PCM Updates — Before replacing any parts. As noted in TSBs, the logic for setting P1404 can be overly sensitive. A PCM reflash may update the diagnostic parameters and resolve the issue without hardware replacement.

Wiring & Ground Locations

• EGR Valve Assembly — Located on the right front of the engine, near the alternator.. This is the primary component for the P1404 code. Its 5-pin connector is the main point for electrical testing of the position sensor (5V supply, ground, signal) and the control solenoid.
• Engine Block Grounds — Key grounding points are located on the engine block, often near the alternator or behind the cylinder heads.. A poor main engine ground can introduce electrical noise and voltage offsets, potentially causing the PCM to misinterpret the EGR position sensor's signal, leading to a false P1404 code.

Real Owner Repair Stories

• JL Wrangler Forums (similar FCA EGR system) (2021 Jeep Wrangler JL Rubicon) — Check Engine Light with code P1404.
  ❌ Tried (didn't work) Replacing the EGR valve and clearing the code with a basic scanner did not work; the light came back immediately.
  ✅ What actually fixed it Taking the vehicle to a mechanic to perform a 'Sequence EGR reset' and flash the PCM with a professional scan tool. This reprogramming was necessary for the computer to recognize the new valve.

OEM Part Supersession History

• 4627465AC, 4627465AD, 4627465AE, 4627465AF → 4627465AG — Standard part evolution, likely for improved reliability or manufacturing process changes to address the internal failures causing P1404.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Hemi Tick / Lifter & Camshaft Failure 🔴 High — A widely documented issue across the Hemi engine family, including the 6.4L. Failures can occur at various mileages, sometimes as low as 3,500 miles, but are often linked to extended idle time and oil lubrication issues. (Ref: No universal recall, but some early 2014 models had a TSB for undersized wrist pins causing similar noise. The lifter failure itself is a known pattern without a specific TSB covering all years.)
• Broken Exhaust Manifold Bolts 🟠 Medium — Very common on 4th and 5th generation Ram trucks with Hemi engines. The rear-most bolts are most susceptible to breaking due to intense heat cycles, causing an exhaust leak tick, especially on cold starts.
• ZF 8-Speed (8HP75) Transmission Problems 🟡 Low — While generally considered a robust transmission, some owners report harsh shifting or require software updates. Outright failures are less common than engine issues. (Ref: Various software update TSBs exist to address shift quality.)
• Uconnect Infotainment System Glitches 🟡 Low — Owners report occasional issues like the rear camera showing a blue or black screen, system freezing, or Bluetooth connectivity problems. These are often intermittent and may be resolved by a vehicle restart or software update. (Ref: Multiple software updates have been released to address system stability and bugs.)

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this specific repair, a used part is NOT recommended. The P1404 code on this platform is overwhelmingly caused by an internal failure of the EGR valve itself, suggesting a design or manufacturing flaw. A used part from a junkyard is highly likely to have the same defect or a limited remaining lifespan.

What to inspect on the donor part:

• Not applicable as used parts are not advised for this component.

OEM-only on this vehicle (don't cheap out):

• Exhaust Gas Recirculation (EGR) Valve

Aftermarket brands forum-validated for this vehicle:

• Standard Motor Products (SMP)
• Wells Vehicle Electronics

Brands owners have reported issues with on this vehicle:

• Unbranded, 'no-name' parts from online marketplaces. Forum and technician reports frequently mention that cheap aftermarket electronic components can be dead-on-arrival or fail quickly, sometimes causing additional circuit codes.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0456 — Often set alongside P1404; relates to an EVAP system leak and is frequently addressed by the same software updates mentioned in TSB #1807123.
• P2457 — EGR Cooling System Performance code; TSB #18-088-22 notes that this fault can erroneously trigger a P1404 'ghost code'.
• P0420 — General emissions-related code that may appear if EGR malfunctions lead to poor combustion and increased load on the catalytic converter.

Frequently Asked Questions