AutoCodes – Generic – P30B5

P30B5 Code - NOx Sensor 2 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 2, NOx Sensor 2 harness is open or shorted, NOx Sensor 2 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: P30B5 indicates NOx Sensor 2 Signal Message Counter Incorrect.
Common causes: Common causes include Faulty NOx Sensor 2, NOx Sensor 2 harness is open or shorted, NOx Sensor 2 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 4,722

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 P30B5 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 2 Signal Message Counter is Incorrect.

OBDII Code P30B5 - NOx Sensor 2 Signal Message Counter Incorrect - AutoCodes.com — P30B5 Code - NOx Sensor 2 Signal Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P30B5?

Faulty NOx Sensor 2
NOx Sensor 2 harness is open or shorted
NOx Sensor 2 circuit poor electrical connection

How to Fix the DTC P30B5?

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 P30B5 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 P30B5 code?

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Need Help with the Code?

Get the P30B5 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P30B5 Buick — NOx Sensor 2 Signal Message Counter Incorrect
P30B5 Cadillac — NOx Sensor 2 Signal Message Counter Incorrect
P30B5 Chevrolet — NOx Sensor 2 Signal Message Counter Incorrect
P30B5 GMC — NOx Sensor 2 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 P30B5 Code

1. What are the common symptoms of OBDII code P30B5 (NOx Sensor 2 Signal Message Counter Incorrect)?

- Common symptoms include poor engine performance, reduced fuel efficiency, and the illumination of the Check Engine Light.

2. What can cause the OBDII code P30B5 to appear?

- The code P30B5 typically appears due to a faulty NOx sensor, wiring issues, or problems with the engine control module.

3. How do I diagnose the cause of OBDII code P30B5?

- Diagnosing the code involves conducting a thorough inspection of the NOx sensor, inspecting the wiring for damage, and using a diagnostic scanner to read live data.

4. Can a DIY enthusiast repair OBDII code P30B5 at home?

- While some may attempt to replace the NOx sensor or repair wiring themselves, it is recommended to seek professional help to ensure proper diagnosis and repair.

5. What are the possible repair options for OBDII code P30B5?

- Repair options may include replacing the NOx sensor, repairing damaged wiring, or reprogramming the engine control module to address the signal message counter discrepancy.

6. How critical is it to address OBDII code P30B5 promptly?

- It is essential to address the code promptly to prevent further damage to the vehicle's emissions system and to maintain optimal engine performance.

7. Can driving with OBDII code P30B5 cause long-term damage to the vehicle?

- Continuously driving with the code may lead to increased emissions, reduced fuel efficiency, and potential damage to the catalytic converter and other engine components.

8. Are there any preventive measures to avoid OBDII code P30B5 in the future?

- Regular maintenance, such as checking and replacing sensors as recommended by the manufacturer, can help prevent the recurrence of OBDII code P30B5.

9. How long does it typically take to repair OBDII code P30B5?

- The repair time can vary depending on the exact cause of the code, but it may take a few hours to a day for diagnosis and repair by a skilled technician.

10. Is it safe to continue driving the vehicle with OBDII code P30B5?

- While the vehicle may still be operable with the code present, it is advisable to have it inspected and repaired as soon as possible to avoid potential complications and ensure optimal performance.