AutoCodes – Generic – P30D5

P30D5 Code - NOx Sensor 3 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 3, NOx Sensor 3 harness is open or shorted, NOx 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: P30D5 indicates NOx Sensor 3 Signal Message Counter Incorrect.
Common causes: Common causes include Faulty NOx Sensor 3, NOx Sensor 3 harness is open or shorted, NOx 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 382

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 P30D5 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 3 Signal Message Counter is Incorrect.

OBDII Code P30D5 - NOx Sensor 3 Signal Message Counter Incorrect - AutoCodes.com — P30D5 Code - NOx Sensor 3 Signal Message Counter Incorrect

What does this mean?

What are the Possible Causes of the DTC P30D5?

Faulty NOx Sensor 3
NOx Sensor 3 harness is open or shorted
NOx Sensor 3 circuit poor electrical connection

How to Fix the DTC P30D5?

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 P30D5 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.

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Need Help with the Code?

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Information for Specific Makes

P30D5 Buick — NOx Sensor 3 Signal Message Counter Incorrect
P30D5 Cadillac — NOx Sensor 3 Signal Message Counter Incorrect
P30D5 Chevrolet — NOx Sensor 3 Signal Message Counter Incorrect
P30D5 GMC — NOx Sensor 3 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 P30D5 Code

What does the OBDII code P30D5 mean?

P30D5 indicates that the NOx sensor 3 signal message counter is incorrect, which means there is a communication issue or malfunction with the NOx sensor system.

What are the common symptoms of a P30D5 code?

Common symptoms include the check engine light being illuminated, reduced engine performance, increased emissions, and possibly failing an emissions test.

What can cause the P30D5 code to trigger?

Causes can include a faulty NOx sensor, damaged wiring or connectors in the NOx sensor circuit, software issues in the engine control module (ECM), or issues with the exhaust system.

How can I diagnose the P30D5 code?

To diagnose the P30D5 code, use an OBD-II scanner to confirm the code, inspect the NOx sensor and its wiring for damage, and check for any other related trouble codes that may provide additional context.

What repairs are commonly needed for a P30D5 code?

Common repairs may include replacing the faulty NOx sensor, repairing or replacing damaged wiring or connectors, updating the ECM software, or addressing any exhaust system issues.

Is it safe to drive with a P30D5 code?

While it may be safe to drive, it is not recommended as the vehicle may have reduced performance and increased emissions. It's best to address the issue promptly.

How much does it typically cost to fix a P30D5 code?

Repair costs can vary widely, ranging from $100 to $500 or more, depending on whether you need to replace the NOx sensor, repair wiring, or update software.

Can I clear the P30D5 code without fixing the problem?

Yes, you can clear the code using an OBD-II scanner, but if the underlying issue is not resolved, the code will likely return after driving the vehicle.

Will a P30D5 code affect my vehicle's fuel economy?

Yes, a P30D5 code can potentially affect fuel economy due to improper fuel management caused by the malfunctioning NOx sensor, leading to less efficient engine operation.