AutoCodes – GMC – P0545 2018 GMC Sierra

P0545 2018 GMC Sierra Code - Exhaust Gas Temperature Sensor 1 Circuit Low 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: P0545 2018 GMC Sierra indicates Exhaust Gas Temperature Sensor 1 Circuit Low 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.

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Code Popularity 495

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
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Code P0545 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 less than 158 Ω for greater than 2 s.

OBDII Code P0545 2018 GMC Sierra - Exhaust Gas Temperature Sensor 1 Circuit Low Voltage - AutoCodes.com — P0545 2018 GMC Sierra Code - Exhaust Gas Temperature Sensor 1 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0545 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 P0545 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 P0545 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 P0545 2018 GMC Sierra code?

Need more information on how to fix the P0545 2018 GMC Sierra code? Get Access to Factory Service Manuals

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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 P0545 2018 GMC Sierra Code

What does the OBDII code P0545 mean on a 2018 GMC Sierra?

P0545 indicates that the Exhaust Gas Temperature (EGT) Sensor 1 circuit is reporting a low voltage signal to the engine control module (ECM).

What are the symptoms of code P0545 on a 2018 GMC Sierra?

Common symptoms include the check engine light turning on, reduced fuel efficiency, potential reduced power mode, and higher exhaust emissions.

What causes the P0545 code to trigger?

Possible causes include a faulty EGT sensor, damaged wiring or connectors in the sensor circuit, corrosion in the electrical connections, or an ECM issue.

Can I drive my 2018 GMC Sierra with the P0545 code?

While the vehicle may still be drivable, ignoring the code can lead to increased emissions, reduced engine performance, and potential damage to the exhaust system components over time.

How do I diagnose the P0545 code on my GMC Sierra?

Start by inspecting the EGT sensor and its wiring for damage or corrosion. Use a multimeter to check the sensor's resistance and verify proper voltage signals in the circuit.

What is the function of the Exhaust Gas Temperature Sensor in my Sierra?

The EGT sensor monitors exhaust temperatures to help optimize emissions control and protect components like the catalytic converter and particulate filter from overheating.

How do I fix the P0545 code on a 2018 GMC Sierra?

Repairs may include replacing the faulty EGT sensor, repairing or replacing damaged wiring, cleaning corroded connections, or reprogramming/updating the ECM if necessary.

How much does it cost to repair code P0545?

Repair costs can vary but typically range from $150 to $300, depending on whether the issue is with the EGT sensor or the wiring.

Can a bad EGT sensor cause other problems in my vehicle?

Yes, a faulty EGT sensor can lead to incorrect engine adjustments, increased emissions, and potential damage to the exhaust system if left unaddressed.

How can I prevent the P0545 code from reoccurring?

Regularly inspect and maintain the exhaust system, check for wiring damage or corrosion, and address any exhaust-related issues promptly to prevent future sensor failures.