Home » OBD Codes » P0546 Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 1)

P0546 Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 1)

Technical Description of OBD-II Trouble Code

The circuit of the Exhaust Gas Temperature (EGT) Sensor in Bank 1 Sensor 1 is registering a high reading.

What does that signify?

This is a generic powertrain code that applies to all makes and models manufactured from 1996 onwards. However, the specific troubleshooting steps may vary depending on the vehicle.

This diagnostic trouble code (DTC) P0546 pertains to the condition of the EGT (exhaust gas temperature) sensor located in the “up” pipe before the catalytic converter. Its main purpose is to protect the converter from damage caused by excessive heat.

Code P0545 is a similar code that indicates a “low” voltage in the circuit. Both codes relate to the condition of the sensor, and the solution is the same for both. This P0546 DTC specifically refers to Bank #1, which is the side of the engine containing cylinder #1. The DTC P0548 is essentially the same, but it applies to bank 2.

An EGT sensor is present in most modern gas or diesel engines. It functions as a heat-sensitive resistor that converts the exhaust temperature into a voltage signal for the computer. It receives a 5-volt signal from the computer through one wire, while the second wire serves as the ground.

The resistance to ground decreases as the exhaust temperature rises, resulting in a higher voltage. Conversely, the resistance increases as the temperature decreases, leading to a lower voltage. If the engine detects a high voltage, the computer will adjust the engine’s timing or fuel ratio to maintain the temperature within acceptable limits for the converter.

In a diesel engine, the EGT is used to determine the timing of regeneration of the PDF (diesel particulate filter) based on the temperature increase.

If a catless up pipe has been installed and the catalytic converter has been removed, there is usually no provision for the EGT sensor. If there is a provision, it will not function correctly without the back pressure, resulting in the code being triggered.

Symptoms

The check engine light will illuminate, and the computer will store the code P0546. No other noticeable symptoms will be present.

Potential Causes

The potential causes for this DTC may include:

  • Check for loose or corroded connectors or terminals, which is often the case
  • Broken wires or missing insulation may be causing a short directly to ground
  • The sensor may have failed
  • A catback exhaust system without EGT provisions installed
  • It’s possible, although not probable, that the computer has failed
  • Repair Procedures

  • Raise the vehicle and locate the sensor. It is situated between the exhaust manifold and the converter or, in the case of a diesel engine, before the Diesel Particulate Filter (DPF). It can be distinguished from the oxygen sensors as it is just a plug with two wires. In a vehicle with a turbo, the sensor will be positioned next to the turbo exhaust input.
  • Inspect the connectors for any abnormalities such as corrosion or loose terminals. Follow the pigtail up to its connector and check that one as well.
  • Look for signs of missing insulation or exposed wires that may be causing a short to ground.
  • Disconnect the upper connector and remove the EGT sensor. Use an ohmmeter to measure the resistance. Probe both terminals in the connector. A functioning EGT sensor should have a resistance of approximately 150 ohms. If the resistance is very low (below 50 ohms), replace the sensor.
  • Apply heat to the sensor using a hair dryer or heat gun while monitoring the ohmmeter. The resistance should decrease as the sensor heats up and increase as it cools down. If this does not occur, replace the sensor.
  • If everything has been satisfactory up to this point, turn the key on and measure the voltage at the engine side of the pigtail. The connector should have a voltage of 5 volts. If not, replace the computer.
  • Another reason for this code to be triggered is if the catalytic converter has been replaced with a catback system. In most states, this is an illegal procedure that can result in a significant fine if caught. It is advisable to check local and state laws regarding the removal of this system, as it leads to uncontrolled emissions being released into the atmosphere. While this may temporarily resolve the issue, it is our responsibility to contribute to keeping the atmosphere clean for future generations.

    Until this issue is repaired, the code can be reset by purchasing a 2.2 ohm resistor from any electronic store for a minimal cost. Simply remove the EGT sensor and plug the resistor into the engine side electrical connector. Secure it with tape, and the computer will be satisfied that the EGT is functioning correctly.

    Professional Service

    While we always recommend resolving this issue through mechanical means, if for some reason that is not possible, we offer the option to permanently delete this specific DTC. All other codes will continue to be addressed. If you are interested in this option, please upload your ECU file to our portal.

    Find out more in our Customer Portal

    Register for free. See detailed specifications and download tuning files.

    One time buyer? Start right away, no registration needed.

    We walk the extra mile.
    Full throttle to the solution

    Continuously improving

    We regularly make improvements to existing files.

    Fast response times

    We are easy to reach and respond quickly to all your questions.

    Developed on dyno

    Many of our tuning files are carefully tested on Dyno and road.

    2251 real customers worldwide

    Guosong HuangQS RACING

    I like your team. Because we have cooperated for 4 years.

    - Thanks a lot for your compliment and for already working with us for the last 4 years.

    Markou ConstantinosAntonis Markou Garage

    I am very happy to meet you guys and I love working with you! Keep going !

    - Dear Antonis, Thanks a lot for your compliments.