EGR Temperature Sensor
Measures the temperature of recirculated exhaust gas, usually after the EGR cooler. It is not the exhaust gas temperature sensor in the tailpipe — that one serves the particulate filter, and confusing the two sends the diagnosis to the wrong end of the engine.
Its job is to confirm the gas is being cooled, because cooling is the entire point of modern EGR: recirculated gas suppresses nitrogen oxide formation by lowering combustion temperature, and hot gas does the opposite. Where two are fitted, they sit either side of the cooler and the difference between them measures the cooler's effectiveness directly — which is why a correlation fault between them can mean either a drifted sensor or a cooler that has stopped cooling.
Soot is its characteristic failure and it is not electrical. The sensor sits in the soot stream, and a coating insulates the element so it reads low and responds slowly — the sensor is undamaged, just buried, and cleaning is often a genuine repair.
Most are negative temperature coefficient thermistors, which inverts how their circuit codes read: a low signal means hot or shorted, a high signal means cold or open — so a circuit-high code on one of these is almost always a broken connection rather than a temperature.
Also known as: egr gas temperature sensor, egrt sensor, exhaust gas recirculation temperature sensor, egr temp sensor
Referenced by 21 codes
Codes involving this component (21)
- P040B Exhaust Gas Recirculation Temperature Sensor A Circuit Range/Performance Moderate
- P040D Exhaust Gas Recirculation Temperature Sensor A Circuit High Moderate
- P040F Exhaust Gas Recirculation Temperature Sensor A/B Correlation Moderate
- P04D0 Exhaust Gas Recirculation Temperature Sensor C Circuit Low Moderate
- P04D1 Exhaust Gas Recirculation Temperature Sensor C Circuit High Moderate
- P040A Exhaust Gas Recirculation Temperature Sensor A Circuit
- P040C Exhaust Gas Recirculation Temperature Sensor A Circuit Low
- P040E Exhaust Gas Recirculation Temperature Sensor A Circuit Intermittent/Erratic
- P041A Exhaust Gas Recirculation Temperature Sensor B Circuit
- P041B Exhaust Gas Recirculation Temperature Sensor B Circuit Range/Performance
- P041C Exhaust Gas Recirculation Temperature Sensor B Circuit Low
- P041D Exhaust Gas Recirculation Temperature Sensor B Circuit High
- P041E Exhaust Gas Recirculation Temperature Sensor B Circuit Intermittent/Erratic
- P04CE Exhaust Gas Recirculation Temperature Sensor C Circuit
- P04CF Exhaust Gas Recirculation Temperature Sensor C Circuit Range/Performance
- P04D2 Exhaust Gas Recirculation Temperature Sensor C Circuit Intermittent/Erratic
- P04E5 Exhaust Gas Recirculation Temperature Sensor D Circuit
- P04E6 Exhaust Gas Recirculation Temperature Sensor D Circuit Range/Performance
- P04E7 Exhaust Gas Recirculation Temperature Sensor D Circuit Low
- P04E8 Exhaust Gas Recirculation Temperature Sensor D Circuit High
- P04E9 Exhaust Gas Recirculation Temperature Sensor D Circuit Intermittent/Erratic
Other components in Exhaust and Emissions
- Oxygen Sensor 326
- EGR Valve 150
- Catalytic Converter 142
- NOx Sensor 118
- Reductant Injector 107
- Exhaust Gas Temperature Sensor 95
- Reductant Tank 95
- Diesel Particulate Filter 76
- SCR Catalyst 65
- EGR Cooler 62
- Exhaust Gas Differential Pressure Sensor 58
- Fuel Tank Pressure Sensor 58
- Exhaust Pressure Control Valve 56
- Reductant Heater 55
- Reductant Pump 51
- EVAP Vent Valve 43
- Exhaust Aftertreatment Fuel Injector 42
- Charcoal Canister 33
- EGR Position Sensor 32
- Secondary Air Injection Pump 32
- Reductant Temperature Sensor 29
- EVAP Leak Detection Pump 29
- EVAP Purge Valve 27
- Particulate Matter Sensor 24
- Reductant Control Module 24
- Reductant Level Sensor 23
- Secondary Air Switching Valve 22
- Secondary Air Check Valve 21
- Catalyst Heater 20
- Catalyst Temperature Sensor 20
- Fuel Filler Cap 18
- EGR Cooler Bypass Valve 16
- Reductant Quality Sensor 16
- Exhaust Back Pressure Sensor 15
- Purge Flow Sensor 13
- Direct Ozone Reduction Catalyst 13
- EGR Vacuum Solenoid 9
- Fuel Vapour Temperature Sensor 5
- Fuel Additive Control Module 4
- Fuel Additive Tank 4
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Working on this component
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about EGR Temperature Sensor.