AutoCodes – Generic – P30B4

P30B4 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 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 3,265

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

What does this mean?

What are the Possible Causes of the DTC P30B4?

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?

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 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 code?

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Need Help with the Code?

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

Information for Specific Makes

P30B4 Buick — NOx Sensor 1 Signal Message Counter Incorrect
P30B4 Cadillac — NOx Sensor 1 Signal Message Counter Incorrect
P30B4 Chevrolet — NOx Sensor 1 Signal Message Counter Incorrect
P30B4 GMC — 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 Code

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

- Common symptoms include reduced engine performance, increased emissions, and the illumination of the check engine light.

2. What can cause the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect?

- The code may be triggered by issues such as a faulty NOx sensor, wiring problems, exhaust leaks, or software glitches in the engine control module.

3. How serious is the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect?

- While the code itself may not cause immediate harm to the vehicle, it can lead to increased emissions and reduced fuel efficiency if left unresolved.

4. Can I continue driving with the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect?

- It is generally not recommended to drive with this code illuminated, as it can lead to further issues with emissions and engine performance.

5. How can I diagnose the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect?

- Diagnosing this code usually involves using a scan tool to retrieve the specific fault codes, checking the NOx sensor's wiring and connections, and performing testing on the sensor itself.

6. Is it possible to reset the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect without fixing the underlying issue?

- While clearing the code with a scan tool may temporarily turn off the check engine light, the root cause of the problem will persist and likely trigger the code again.

7. Can I repair the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect myself?

- Depending on your skill level and access to tools, you may be able to address some simple causes like loose connections, but more complex issues may require professional diagnosis and repair.

8. How much does it typically cost to fix the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect?

- The cost of repair can vary widely depending on the underlying issue, but it may involve replacing the NOx sensor, repairing wiring, or updating software in the engine control module.

9. Will ignoring the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect lead to further damage?

- Ignoring this code can potentially lead to increased emissions, reduced fuel efficiency, and other related issues over time, so it is best to address it promptly.

10. How long does it usually take to repair the OBDII code P30B4 NOx Sensor 1 Signal Message Counter Incorrect?

- The repair time can vary depending on the specific cause of the code and the availability of parts, but it may range from a few hours to a day in most cases.