The exhaust gas recirculation (EGR) system is designed to lower combustion temperatures and reduce oxides of nitrogen emissions (NOx). To do this, exhaust gases are introduced into the engine combustion chamber to cool the combustion flame. Some vehicles use an EGR temperature sensor to determine EGR operation. This information is used by the powertrain control module (PCM) for proper EGR control.
On most modern diesel engines, an EGR cooler is used to cool the temperature of the exhaust gas before it enters the engine. The PCM relies on the EGR temperature sensors to monitor the cooler’s operation. Generally, one temperature sensor is located on the exhaust manifold, and one is located near the EGR valve.
The typical symptoms of a failed EGR temperature sensor include pinging, increased emissions and an illuminated Check Engine Light.
Part 1 of 3: Locate the EGR temperature sensor
In order to safely and efficiently replace your EGR temperature sensor you need a couple of basic tools:
Step 1: Locate the EGR temperature sensor. The EGR temperature sensor is usually mounted in the exhaust manifold or mounted near the EGR valve.
Part 2 of 3: Remove the EGR temperature sensor
Step 1: Disconnect the negative battery cable. Disconnect the negative battery cable and set it aside.
Step 2: Remove the electrical connector. Remove the electrical connector by pushing down on the tab and sliding it off.
Step 3: Unscrew the sensor. Unscrew the sensor using a ratchet or wrench.
Remove the sensor.
Part 3 of 3: Install the new EGR temperature sensor
Step 1: Put in the new sensor. Mount the new sensor in position.
Step 2: Screw in the new sensor. Screw in the new sensor by hand and then tighten it down using a ratchet or wrench.
Step 3: Reinstall the electrical connector. Connect the electrical connector by sliding it into place.
Step 4: Reconnect the negative battery cable. Reconnect the negative battery cable and tighten it down.
You should now have a new EGR temperature sensor installed! If this procedure is something you prefer to leave to the professionals, the team at YourMechanic offers expert EGR temperature sensor replacement.
This article originally appeared on YourMechanic.com as How to Replace an Exhaust Gas Recirculation (EGR) Temperature Sensor and was authored by Mia Bevacqua.