There is no universal location for EGR temperature sensor B; in most engines it is mounted on or near the EGR valve or EGR cooler, typically on the exhaust side of the system. Some designs place it on the EGR pipe itself, downstream of the valve. For the exact position on your vehicle, refer to the factory service manual or a vendor schematic for your engine code.
Exhaust Gas Recirculation (EGR) temperature sensors monitor the temperature of the recirculated exhaust and help the engine control unit prevent excessive temperatures or soot formation. The "B" designation usually indicates the sensor on the downstream side, but configurations vary by manufacturer and engine family. This article outlines common placements and how to locate the sensor on your model.
Common placement patterns
Across many makes and models, you can expect EGR temperature sensor B to appear in one of a few standard spots. The list below captures typical locations commonly seen on modern engines.
- On or immediately adjacent to the EGR valve housing, often at the base where the valve connects to the intake/exhaust ports.
- On the EGR cooler inlet or outlet, mounted on the cooler housing or pipe near the valve.
- On the EGR pipe or elbow between the exhaust manifold and the EGR valve, sometimes integrated into a flange or connector.
- In a few designs, mounted directly on the intake or a common EGR adapter that splits to multiple passages; in these cases, it may be labeled as EGR T or EGR Temperature Sensor B.
These placements reflect common patterns but do not replace a model-specific diagram. In many modern vehicles, the B sensor is paired with an A sensor as part of an exhaust-temperature feedback loop.
How to locate your specific vehicle
To confirm the exact position for your car, follow these steps:
- Identify your engine code and model year; this helps you pull the correct service diagram from the manufacturer or a repair database.
- Follow the EGR plumbing from the exhaust manifold toward the intake, looking for a two- or three-wire sensor with a label like EGR, EGRT, or EGR TEMP; the B sensor is usually the downstream one.
- Check connectors and harness routing; sensors often sit on brackets or flanges with a 2- or 3-pin connector.
- Consult the vehicle’s service manual or an OEM parts diagram for the exact sensor designation and location on your engine family.
- If in doubt, have a qualified technician verify the location and diagnose using manufacturer diagnostic procedures.
Knowing where to look can save time, and using official diagrams reduces the risk of tampering with the wrong sensor in a crowded EGR assembly.
Summary
There is no universal answer for the location of EGR temperature sensor B; it is typically found on the exhaust side near the EGR valve or EGR cooler, or on the EGR pipe itself. Always consult the vehicle’s service manual for your specific engine code and model year, and use reliable diagrams to confirm the exact spot before handling electrical connectors or replacing parts.