EGR Cooler Efficiency Below Threshold
2013-2018 Ram 2500 6.7L I6 Cummins Diesel
Description
The EGR cooler is not reducing exhaust gas temperature sufficiently. This can indicate an internal leak or coolant passage blockage.
Symptoms
- Check Engine Light
- Elevated intake manifold temperature
- Increased NOx emissions
- Coolant level dropping slowly
- White smoke from exhaust (coolant)
- Sweet smell from exhaust
Common Causes
- EGR cooler internal leak
- EGR cooler coolant passage blocked
- EGR cooler fins clogged with soot
- Thermostat affecting coolant temperature
- Insufficient coolant flow through cooler
Diagnostic Steps
- Compare EGR cooler inlet and outlet temperatures
- Check coolant level and condition
- Pressure test EGR cooler
- Inspect exhaust for coolant contamination
- Monitor coolant consumption
Repair Notes
Replace EGR cooler if leaking or if efficiency cannot be restored. An internal leak can cause catastrophic engine damage from hydro-lock.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
P3871 on Other Vehicles
Common Questions
What does code P3871 mean on a 2013-2018 Ram 2500?
P3871 stands for "EGR Cooler Efficiency Below Threshold". The EGR cooler is not reducing exhaust gas temperature sufficiently. This can indicate an internal leak or coolant passage blockage.
What are the symptoms of P3871 on a Ram 2500?
Common symptoms of P3871 include: Check Engine Light, Elevated intake manifold temperature, Increased NOx emissions, Coolant level dropping slowly, White smoke from exhaust (coolant), Sweet smell from exhaust.
What causes P3871 on a 2013-2018 Ram 2500?
Common causes of P3871 include: EGR cooler internal leak, EGR cooler coolant passage blocked, EGR cooler fins clogged with soot, Thermostat affecting coolant temperature, Insufficient coolant flow through cooler.