Automotive Sensor

What are the functions of the EGT sensor in the engine management system?
1. Real-time monitoring of exhaust temperature to protect the aftertreatment system
The EGT sensor accurately measures exhaust pipe temperature, helping the engine control unit (ECU) determine whether heating or fuel injection is necessary to prevent catalytic converter failure due to low temperatures.

2. Optimizing fuel economy and emissions control
By providing feedback on exhaust temperature, the system can adjust the air-fuel ratio under different operating conditions, achieving lower fuel consumption and better emissions compliance.

3. Supporting fault diagnosis and early warning
When exhaust temperature is abnormal, the ECU can quickly identify and record fault codes, providing a basis for repair and preventing damage to the sensor or exhaust components caused by overheating.

4. Improving engine power and responsiveness
Under high loads or during acceleration, appropriately increasing exhaust temperature can speed up turbocharger response and increase engine output. This function is particularly critical in modern high-performance vehicles.
How do I determine if the EGT sensor needs to be replaced?
1. Temperature Reading Deviation or Instability
When the actual measured exhaust temperature differs significantly from the ECU's expected value, and the error fluctuates over time, it's often due to signal distortion caused by aging or contamination of the sensor's internal components.

2. DTCs (such as P0106 ​​and P0107)
When the ECU detects a failure or abnormal signal from an upstream or downstream temperature sensor, it will log the corresponding DTC, prompting the need to inspect or replace the EGT sensor.

3. Heating Failure
Many EGT sensors have built-in heating elements to ensure measurement accuracy during low-temperature startups. Abnormal heating current or excessive heating time indicates damage to the heating circuit or sensor element, requiring replacement.

4. Deposits or Corrosion Detected During Visual Inspection
Prolonged operation in high-temperature, highly corrosive gas environments may cause carbon deposits, metal corrosion, or cracks to form on the sensor surface. These visible signs of damage are direct evidence of replacement.