P2084 on 2011-2018 Ram 5500 6.7L Cummins: EGT Sensor Performance Causes and Fixes

What's Unique About the 2011-2018 Ram 5500

The 6.7L Cummins engine relies on a series of EGT sensors to manage its complex aftertreatment system. P2084 specifically points to 'Sensor 2', which is positioned at the DPF inlet. A failure of this particular sensor directly disables the truck's ability to perform an active DPF regeneration. This makes addressing the code more urgent than on a gasoline vehicle, as continued driving will inevitably lead to a soot-clogged DPF, a common and expensive failure point on these trucks. Driving more than 50-100 miles with this code active can cause irreversible DPF damage.

Symptoms You May Notice

• Check Engine Light (Malfunction Indicator Lamp) is on.
• Message on the instrument cluster display (e.g., 'Service Exhaust System', 'Exhaust System Service Required - See Dealer').
• Vehicle may enter a reduced power 'limp mode'.
• DPF regeneration process will be inhibited.
• Reduced fuel economy.
• Failed emissions test.
• Abnormal exhaust smoke.

Most Likely Causes

1. Faulty EGT Sensor (Bank 1, Sensor 2) 🔴 High Probability EGT sensors are subjected to extreme temperatures (up to 2300°F), constant vibration, and corrosive exhaust gases, making them a common wear-and-tear item on diesel exhaust systems.
   How to confirm: With the engine cold (after sitting overnight), use a scan tool to view live data for all EGT sensors. They should all read within a few degrees of the ambient air temperature. If the sensor in question (Sensor 1/2) reads a wildly different value (e.g., -40°F or over 5000°F), a default value, or doesn't change with the engine running, it has failed. You can also test the sensor's internal resistance with a multimeter; a reading below 50 ohms often indicates failure, though an open circuit (infinite resistance) is also a definitive sign of a bad sensor.
   Typical fix: Replace the EGT sensor located at the DPF inlet. Apply anti-seize compound to the threads and torque to specification (typically around 33 ft-lbs). 🎬 See this walkthrough on how to install an EGT sensor.
   Est. part cost: $70-$150
2. Damaged Wiring or Connector 🟡 Medium Probability The wiring harness runs along the chassis and near hot exhaust components, making it susceptible to melting, chafing, or corrosion from road salt and debris. The connectors themselves can also become contaminated with soot or moisture.
   How to confirm: Visually inspect the entire wiring pigtail from the EGT sensor to the main harness. Look for melted plastic, frayed wires, or green/white corrosion inside the connector. Wiggle the harness while monitoring live sensor data on a scan tool to see if the reading fluctuates, indicating an intermittent connection. A diagnostic test involves shorting the two terminals of the harness-side connector with the key on; if a different code (like P2032 for circuit low) appears, the wiring is likely good and the sensor is bad.
   Typical fix: Repair the damaged section of wire 🎬 Watch: How to fix the exhaust gas sensor module wiring. or replace the connector pigtail. Ensure the new wiring is properly secured away from heat sources.
   Est. part cost: $20-$50

Rare But Worth Checking

• Large Exhaust Leak: A significant exhaust leak before the EGT sensor can allow cool ambient air to enter the exhaust stream, causing the sensor to report a temperature that is implausibly low to the PCM. This is usually accompanied by loud exhaust noise and visible soot trails near flanges or gaskets.
• Faulty Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is extremely rare. Before condemning the PCM, all other possibilities, including the sensor and wiring, must be exhaustively ruled out. A technician would verify that the 5-volt reference and ground signals are present at the sensor connector.

Diagnosis Steps

1. Connect an OBD-II scanner and confirm P2084 is the primary code. Note any other codes present, such as P2080, P2463, or P2033.
2. Allow the vehicle to sit overnight ('cold soak'). Turn the key to the 'On' position without starting the engine.
3. Use the scan tool to monitor live data from all EGT sensors. They should all read within 5°F of each other and the ambient air temperature. If Sensor 1/2 shows a default high reading (e.g., 5928°F) or a very low/illogical reading (e.g., -40°F), the sensor is likely faulty.
4. If the cold readings are normal, start the engine and monitor the EGT sensor data as the engine warms up. All sensor readings should rise. If Sensor 1/2 is slow to respond or doesn't respond at all, this confirms a performance issue.
5. If the sensor appears to be the issue, turn off the vehicle and disconnect the battery.
6. Locate EGT Sensor 1/2 at the inlet of the DPF.
7. Disconnect the sensor and inspect the connector and wiring for any signs of damage, melting, or corrosion. Repair as needed.
8. If the wiring is okay, you can test the sensor itself. Using a multimeter, check the resistance across the sensor's two pins. Compare this reading to the manufacturer's specification. An open circuit (infinite resistance) or resistance below 50 ohms confirms a bad sensor.
9. If the sensor and wiring test good, the issue may be intermittent or, in rare cases, a problem with the PCM. Check for exhaust leaks upstream of the sensor.

Parts You'll Likely Need

• Exhaust Gas Temperature (EGT) Sensor (Bank 1 Sensor 2) (OEM #68206021AA) — This sensor is the most frequent point of failure for this code due to the harsh operating environment of the exhaust system.
  Trusted brands: Mopar, Bosch, Walker Products, Standard Motor Products (SMP), Bostech
  OEM price range: $120-$180
  Aftermarket price range: $70-$150

Related Codes That Often Appear With This One

• P2080 — This code is for EGT Sensor 1. If they appear together, it may point to a shared wiring harness issue or a PCM software fault rather than two failed sensors.
• P2463 — This code means 'Diesel Particulate Filter - Soot Accumulation'. The P2084 fault prevents DPF regeneration, causing soot to build up and trigger this code.
• P2002 — This code means 'DPF Efficiency Below Threshold'. It is often a direct result of the P2084 code preventing proper regeneration. Always fix the EGT code first.
• P2033 — This is a related code for 'Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 2'. It often appears alongside P2084 and points to the same faulty sensor or circuit.

Platform-Specific Known Issues

• Owner Experience: Sensor Failure Confirmed by Dealer: An owner on the Turbo Diesel Register forum reported an 'Exhaust System Service Required' message and codes P2033 and P24A0. Their scan tool showed the EGT-2 sensor reading either 40°F or 5928°F at operating temperature. Despite one dealer suggesting a clogged DPF, a second dealer correctly diagnosed and replaced the faulty EGT sensor, resolving the issue.

Mechanic-Grade Diagnostic Values

• EGT Sensor Resistance (PTC Type) — expected: Approximately 215-220 Ohms at room temperature.. Failure: A reading below 50 Ohms or an open circuit (infinite resistance) indicates a failed sensor.
• EGT Sensor Signal Voltage (at PCM) — expected: The voltage should vary based on temperature. The PCM supplies a 5V reference.. Failure: A signal voltage that is stuck high (above 4.88V) or low, or does not change as the exhaust heats up, indicates a problem in the circuit or sensor.
• EGT Sensor Installation Torque — expected: 33 ft-lbs (45 Nm). Failure: Over-torquing can damage the sensor or threads; under-torquing can lead to exhaust leaks and inaccurate readings.

Scan Tool Commands That Help

• wiTECH or equivalent professional scan tool: Shorting the harness-side connector terminals — With the sensor disconnected and key on, shorting the two terminals on the vehicle's harness connector should force a different code (e.g., P2032 - Circuit Low). If the new code appears, it confirms the wiring and PCM are likely good, isolating the fault to the sensor itself.
• wiTECH: SCR DEF Tank Fluid Level Reset — This procedure is required after reprogramming the PCM, such as when performing the software update outlined in TSB 18-028-14, to ensure the aftertreatment system functions correctly.

Wiring & Ground Locations

• EGT 1/2 Sensor Connector — The sensor is located at the inlet of the Diesel Particulate Filter (DPF) assembly. The connector is a pigtail attached to the sensor body.. This is the primary connection point for the faulty sensor. It is exposed to high heat, vibration, and road debris, making it a common point of failure due to melting, corrosion, or broken wires.
• PCM Connector C2 — The Powertrain Control Module (PCM) is located on the driver's side of the engine block. Connector C2 is one of the main harness connections to the module.. The wires from the EGT 1/2 sensor terminate at specific pins within this connector. Advanced diagnostics may require testing for continuity and voltage directly at these pins to rule out a wiring issue between the sensor and the PCM.

Real Owner Repair Stories

• Turbo Diesel Register forum (2014 Ram 2500 Limited 6.7L Cummins, 76k miles) — 'Exhaust System Service Required' message on EVIC. Scan tool showed EGT-2 (DOC Outlet Temp) reading either 40°F or 5928°F. Codes P2033 and P24A0 were present.
  ❌ Tried (didn't work) Initial dealership diagnosis suggested a clogged DPF filter, which was incorrect.
  ✅ What actually fixed it The user was advised by another forum member that the issue was almost certainly the sensor itself, not the DPF. The diagnostic advice was to replace the EGT 1/2 sensor, which would then allow the disabled regeneration process to complete and clear the related codes.

OEM Part Supersession History

• 68067129AA, 68067129AB → 68206021AA — Part has been updated by the manufacturer.
  Heads up: The newest part number, 68206021AA, is the correct replacement for the earlier versions and should be used for all repairs.

Model Year Variations Within This Range

• 2013-2018: Starting in 2013, Ram added a Selective Catalytic Reduction (SCR) system with Diesel Exhaust Fluid (DEF) injection to the 6.7L Cummins platform. This made the aftertreatment system more complex than the 2011-2012 models, adding more components (like NOx sensors and DEF injectors) but the function and location of the EGT sensor for P2084 remained consistent.
• 2013-2018: Emissions Recall 67A was issued for 2013-2018 models, involving a PCM software update to modify DEF dosing rates. This update can affect the overall behavior of the emissions system and is a critical piece of vehicle history to be aware of when diagnosing any aftertreatment codes.

Diagnostic Flowchart

Other Known Issues on This Vehicle

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

• EGR Cooler Failure 🔴 High — Common across all 6.7L Cummins years. Soot buildup clogs the cooler, leading to cracks and internal coolant leaks. Symptoms include unexplained coolant loss and white smoke/steam from the exhaust.
• VGT Turbocharger Actuator Failure 🔴 High — A very common failure point, especially on 2013-2018 models. The electronic actuator fails, causing loss of power, no exhaust brake function, and codes like U010C, P00AF, and P003A. The failure is often due to soot buildup inside the variable geometry turbo, which strains the actuator motor. (Ref: X99 Warranty Extension (15yr/150k miles) for some 2015 models.)
• Clogged Diesel Particulate Filter (DPF) 🟠 Medium — More common on pre-2013 models that did not use DEF, but still occurs on later models, especially with frequent short trips or idling. Failure of components like the EGT sensor (causing P2084) will directly lead to DPF clogging by inhibiting regeneration.
• Heater Grid Bolt Failure 🔴 High — A known, though not extremely common, issue where the bolt holding the heater grid can break off and fall into the engine, causing catastrophic internal damage.
• Water Pump Leaks 🟠 Medium — Water pumps are a common wear item, with leaks often developing at higher mileage, especially on trucks that tow frequently.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: Never. EGT sensors are electronic components that function as wear items due to constant exposure to extreme heat cycles, vibration, and corrosive exhaust gases. A used sensor has unknown remaining life and is highly likely to fail prematurely, causing the same problem to return. The labor to replace the part again outweighs any initial savings.

What to inspect on the donor part:

• Not applicable. Do not purchase a used EGT sensor.

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

• While not strictly 'OEM-only', using a genuine Mopar sensor or a high-quality Tier 1 aftermarket equivalent (Bosch, SMP) is strongly recommended. Cheap, unbranded sensors are known to have high failure rates and may not report temperatures accurately, leading to persistent codes or improper DPF regeneration.

Aftermarket brands forum-validated for this vehicle:

• Bosch
• Standard Motor Products (SMP)
• Walker Products
• Bostech

Brands owners have reported issues with on this vehicle:

• Unbranded, no-name sensors from online marketplaces should be avoided due to a high likelihood of premature failure and inaccurate readings.

Real Owner Stories

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

Related OBD-II Codes

• P2033 — This is a circuit-specific code (Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 2) for the exact same sensor that causes P2084. They frequently appear together and point to a failed sensor or wiring issue.
• P2463 — This code for 'DPF Soot Accumulation' is a direct consequence of an unresolved P2084. A faulty EGT sensor inhibits DPF regeneration, causing soot to build up and eventually trigger this code.
• P2080 — This code is for the EGT sensor located before the turbo (Bank 1, Sensor 1). While it's a different sensor, it's part of the same system and is often checked during diagnosis of any EGT-related fault.
• P2032 — This is the 'Circuit Low' code for the same EGT sensor (Bank 1, Sensor 2). It can appear due to a wiring short or failed sensor, and is sometimes intentionally triggered during diagnostics to test the wiring harness.
• P24A0 — This code for 'DPF Regeneration Incomplete' was reported by an owner alongside an EGT sensor code. It is directly related because the incorrect temperature data from a faulty sensor prevents the regeneration cycle from completing successfully.

Frequently Asked Questions