AutoCodes – GMC – P242C GMC

P242C GMC Code - Exhaust Gas Temperature Sensor 3 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) 3, Exhaust Gas Temperature Sensor 3 harness is open or shorted, Exhaust Gas Temperature Sensor 3 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P242C GMC indicates Exhaust Gas Temperature Sensor 3 Circuit Low Voltage.
Common causes: Common causes include Faulty Exhaust Gas Temperature Sensor (EGTS) 3, Exhaust Gas Temperature Sensor 3 harness is open or shorted, Exhaust Gas Temperature Sensor 3 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,133

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 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 P242C GMC 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 P242C GMC - Exhaust Gas Temperature Sensor 3 Circuit Low Voltage - AutoCodes.com — P242C GMC Code - Exhaust Gas Temperature Sensor 3 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P242C GMC?

Faulty Exhaust Gas Temperature Sensor (EGTS) 3
Exhaust Gas Temperature Sensor 3 harness is open or shorted
Exhaust Gas Temperature Sensor 3 circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P242C GMC?

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 P242C GMC 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 P242C GMC code?

Need more information on how to fix the P242C GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P242C GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P242C 2014 GMC Sierra — Exhaust Gas Temperature Sensor 3 Circuit Low Voltage
P242C 2015 GMC Sierra — Exhaust Gas Temperature Sensor 3 Circuit Low Voltage
P242C 2016 GMC Sierra — Exhaust Gas Temperature Sensor 3 Circuit Low Voltage
P242C 2017 GMC Sierra — Exhaust Gas Temperature Sensor 3 Circuit Low Voltage
P242C 2018 GMC Sierra — Exhaust Gas Temperature Sensor 3 Circuit Low Voltage

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 P242C GMC Code

1. What are the common symptoms of OBDII code P242C GMC (Exhaust Gas Temperature Sensor 3 Circuit Low Voltage)?

The common symptoms of this code may include poor engine performance, increased fuel consumption, and the illumination of the Check Engine Light.

2. What could cause the OBDII code P242C GMC to trigger?

The trigger of code P242C GMC is often caused by a faulty exhaust gas temperature sensor, damaged wiring or connectors, or issues with the sensor circuit.

3. How can I diagnose the OBDII code P242C GMC at home?

You can diagnose the code P242C GMC at home using an OBDII scanner to read the trouble codes and checking the exhaust gas temperature sensor and its wiring for any visible damage.

4. Is it safe to continue driving with the OBDII code P242C GMC present?

It is not recommended to continue driving with the code P242C GMC present, as it can lead to further damage to the vehicle and may result in poor engine performance.

5. Can I repair the OBDII code P242C GMC myself?

Repairing the code P242C GMC may require some technical knowledge and tools. If you are familiar with automotive repairs, you may be able to replace the exhaust gas temperature sensor or repair any damaged wiring yourself.

6. How much does it cost to repair the OBDII code P242C GMC at a repair shop?

The cost of repairing the code P242C GMC at a repair shop can vary depending on the extent of the damage and the labor rates in your area. It is advisable to get a few quotes from different shops.

7. Will resetting the Check Engine Light make the OBDII code P242C GMC go away?

Resetting the Check Engine Light will temporarily turn off the light, but it will not fix the underlying issue causing the code. The code is likely to return until the root cause is addressed.

8. What are some tips to prevent the OBDII code P242C GMC from reoccurring?

To prevent the code P242C GMC from reoccurring, it is important to regularly maintain your vehicle, check the condition of sensors and wiring, and address any issues promptly.

9. How urgent is it to address the OBDII code P242C GMC?

It is recommended to address the code P242C GMC as soon as possible to prevent further damage to your vehicle and ensure optimal engine performance.

10. Can the OBDII code P242C GMC be related to other engine issues?

While the code P242C GMC specifically relates to the exhaust gas temperature sensor circuit, it can also be related to other engine issues such as fuel system problems or sensor malfunctions.