AutoCodes – GMC – P30B4 GMC

P30B4 GMC Code - NOx Sensor 1 Signal Message Counter Incorrect

Quick Answer

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Common causes include Faulty NOx Sensor 1, NOx Sensor 1 harness is open or shorted, NOx Sensor 1 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: P30B4 GMC indicates NOx Sensor 1 Signal Message Counter Incorrect.
Common causes: Common causes include Faulty NOx Sensor 1, NOx Sensor 1 harness is open or shorted, NOx Sensor 1 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 1,087

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 Sep 29, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P30B4 GMC Description

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Operating information and commands are exchanged among the control modules. Each module on the serial data circuit maintains a transmit error counter and a receive error counter. The counter values increase with detected errors and decrease with error-free messages. The Diagnostic Trouble Code (DTC) will be set when the NOx Sensor 1 Signal Message Counter is Incorrect.

OBDII Code P30B4 GMC - NOx Sensor 1 Signal Message Counter Incorrect - AutoCodes.com — P30B4 GMC Code - NOx Sensor 1 Signal Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P30B4 GMC?

Faulty NOx Sensor 1
NOx Sensor 1 harness is open or shorted
NOx Sensor 1 circuit poor electrical connection

How to Fix the DTC P30B4 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P30B4 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 P30B4 GMC code?

Need more information on how to fix the P30B4 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P30B4 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P30B4 2014 GMC Sierra — NOx Sensor 1 Signal Message Counter Incorrect
P30B4 2015 GMC Sierra — NOx Sensor 1 Signal Message Counter Incorrect
P30B4 2016 GMC Sierra — NOx Sensor 1 Signal Message Counter Incorrect
P30B4 2017 GMC Sierra — NOx Sensor 1 Signal Message Counter Incorrect
P30B4 2018 GMC Sierra — NOx Sensor 1 Signal Message Counter Incorrect

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 P30B4 GMC Code

1. What are the common symptoms of OBDII code P30B4 GMC (NOx Sensor 1 Signal Message Counter Incorrect)?

- The common symptoms include poor engine performance, decreased fuel efficiency, and the illumination of the check engine light.

2. What are the possible causes of OBDII code P30B4 GMC?

- Possible causes may include a faulty NOx sensor, issues with the NOx sensor wiring or connector, or problems with the engine control module (ECM).

3. How serious is OBDII code P30B4 GMC?

- This code should be addressed promptly as it can lead to increased emissions and potential damage to the catalytic converter and other emission control components.

4. How can I diagnose OBDII code P30B4 GMC?

- Diagnosing this code typically involves using a diagnostic scanner to retrieve the code, inspecting the NOx sensor and its wiring, and testing the sensor's functionality.

5. Can I continue driving with OBDII code P30B4 GMC?

- It is not recommended to continue driving with this code present, as it can impact the vehicle's performance and emissions output.

6. How can OBDII code P30B4 GMC be repaired?

- Repair options may include replacing the faulty NOx sensor, repairing or replacing damaged wiring or connectors, and resetting the ECM to clear the code.

7. Will OBDII code P30B4 GMC cause my vehicle to fail an emissions test?

- Yes, this code can cause your vehicle to fail an emissions test due to increased emissions output.

8. Can a DIY enthusiast fix OBDII code P30B4 GMC?

- While some basic troubleshooting steps can be performed by DIY enthusiasts, diagnosing and repairing this code may require advanced tools and expertise, so consulting a professional is recommended.

9. How much does it cost to repair OBDII code P30B4 GMC?

- The cost of repairing this code can vary depending on the cause of the issue, the necessary parts, and labor costs. It is advisable to obtain quotes from local mechanics or repair shops.

10. What is the best way to prevent OBDII code P30B4 GMC from occurring?

- Regular maintenance, including timely sensor inspections and replacements, can help prevent the occurrence of OBDII code P30B4 GMC.