P0546 - EXHAUST GAS TEMPERATURE (EGT) SENSOR CIRCUIT HIGH BANK 1 SENSOR 1

The DTC code P0546 OBDII refers to the EGT (Exhaust Gas Temperature) Sensor located in the pipe, in front of the Catalytic Converter (TWC). The purpose of this sensor is to protect the converter from excessive heat.

The resistance of the sensor is sensitive to heat. It converts the exhaust temperature into an electrical signal, which is sent to the vehicle’s computer. The higher the temperature in the exhaust, the lower the resistance to the ground, resulting in a high voltage. If the temperature drops, the resistance increases, and the voltage are lower. When the engine detects a high voltage, the PCM (Powertrain Control Module) is responsible for changing the engine timing or fuel ratio to keep the temperature in acceptable ranges within the TWC (Catalytic Converter).

If the voltage sent to the PCM exceeds the limits already set by the vehicle manufacturer, this code is stored and the Check Engine light will illuminate.

• MIL (Engine Malfunction) light on.

The reasons for setting the diagnostic code P0546 OBD2 are

• Poor connections or corroded terminals.
• Short to ground in the circuit.
• The EGT Sensor may be damaged.
• Decreased back pressure in the exhaust system.
• Exhaust leaks.

To solve the problems caused by the error code P0546 OBDII, you can do this:

• Locate the Exhaust Gas Temperature (EGT) Check connectors for loose terminals or bad wires, repair if you find any problem.
• Disconnect the EGT Sensor and test its resistance with a multimeter on the ohm scale. Perform the test on both terminals. If the sensor is OK, you should get a reading of 150 ohms. A large reading that is lower indicates that the sensor is damaged, you should replace it.
• You can check the status of the EGT sensor by heating the sensor, then with the ohmmeter connected, see if the sensor resistance drops as the sensor heats up. If not, replace it.