AutoCodes – GMC – P0546 2018 GMC Sierra

P0546 2018 GMC Sierra Code - Exhaust Gas Temperature Sensor 1 Circuit High Voltage

Quick Answer

The Exhaust Gas Temperature sensors (EGTS) are variable resistors that measure the temperature of the exhaust gas. Common causes include Faulty Exhaust Gas Temperature Sensor (EGTS) 1, Exhaust Gas Temperature Sensor 1 harness is open or shorted, Exhaust Gas Temperature Sensor 1 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0546 2018 GMC Sierra indicates Exhaust Gas Temperature Sensor 1 Circuit High Voltage.
Common causes: Common causes include Faulty Exhaust Gas Temperature Sensor (EGTS) 1, Exhaust Gas Temperature Sensor 1 harness is open or shorted, Exhaust Gas Temperature Sensor 1 circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 194

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 03, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0546 2018 GMC Sierra Description

The Exhaust Gas Temperature sensors (EGTS) are variable resistors that measure the temperature of the exhaust gas. Exhaust temperature sensor 1 is the first exhaust temperature sensor in the exhaust system, the following exhaust temperature sensors are counted upward from the engine outlet to the exhaust system end. The Engine Control Module (ECM) supplies 5 V to the exhaust gas temperature signal circuit and supplies a ground to the low reference circuit. The exhaust gas temperature sensor temperature information is used by the ECM during the exhaust gas particulate filter cleaning process. The Diagnostic Trouble Code (DTC) will ve set when the ECM detects that the exhaust gas temperature sensor is greater than 900 Ω for greater than 2 s.

OBDII Code P0546 2018 GMC Sierra - Exhaust Gas Temperature Sensor 1 Circuit High Voltage - AutoCodes.com — P0546 2018 GMC Sierra Code - Exhaust Gas Temperature Sensor 1 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P0546 2018 GMC Sierra?

Faulty Exhaust Gas Temperature Sensor (EGTS) 1
Exhaust Gas Temperature Sensor 1 harness is open or shorted
Exhaust Gas Temperature Sensor 1 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0546 2018 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

After starting the engine, the exhaust gas temperature sensor temperature should rise steadily, then stabilize after the engine reaches operating temperature. Exhaust gas temperature sensors may fail intermittently while operating under extreme temperatures. Review the Freeze Frame/Failure Records to verify the failure criteria.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0546 2018 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0546 2018 GMC Sierra code?

Need more information on how to fix the P0546 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0546 2018 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0546 2018 GMC Sierra Code

1. What does the OBDII code P0546 mean on a 2018 GMC Sierra?

P0546 indicates a high voltage issue in the circuit for Exhaust Gas Temperature Sensor 1, which monitors the temperature of exhaust gases to optimize performance and emissions control.

2. What are the common symptoms of code P0546 on a 2018 GMC Sierra?

Symptoms may include a check engine light, reduced engine performance, poor fuel economy, excessive exhaust smoke, or the vehicle entering limp mode.

3. What causes the P0546 code to trigger on a 2018 GMC Sierra?

Common causes include a faulty exhaust gas temperature sensor, damaged wiring or connectors in the sensor circuit, or issues with the engine control module (ECM).

4. Can a dirty or clogged exhaust system cause the P0546 code?

While less common, a clogged exhaust system can cause excessive heat buildup, potentially damaging the sensor or its circuit and triggering the code.

5. How do you diagnose the P0546 code on a 2018 GMC Sierra?

Diagnosis typically involves using a scan tool to confirm the code, visually inspecting the wiring and connectors for damage, and testing the sensor's resistance and voltage output.

6. Can I drive my 2018 GMC Sierra with the P0546 code?

Driving is not recommended, as ignoring this code can lead to further damage to the exhaust system, reduced performance, and increased emissions.

7. How is the P0546 code fixed on a 2018 GMC Sierra?

Repairs may include replacing the faulty exhaust gas temperature sensor, repairing damaged wiring or connectors, or reprogramming the ECM if necessary.

8. How much does it cost to fix the P0546 code on a 2018 GMC Sierra?

Repair costs can range from $100 to $300, depending on whether the sensor needs replacement or if wiring repairs are required.

9. Can a software update fix the P0546 code on a 2018 GMC Sierra?

In rare cases, a software update to the ECM may resolve the issue if itâ€™s related to incorrect sensor readings or calibration.

10. How can I prevent the P0546 code from occurring on my 2018 GMC Sierra?

Regular maintenance, ensuring the exhaust system is clean and intact, and addressing wiring issues promptly can help prevent this code from recurring.