AutoCodes – Generic – U1331

U1331 Code - Software Incompatibility with Body Control Module

Quick Answer

This Diagnostic Trouble Code (DTC) is stored when the destination information of the Main Body ECU (Multiplex Network Body ECU) does not match that of the Blind Spot Monitor Sensors. Common causes include Faulty Main Body ECU (Multiplex Network Body ECU), Faulty Blind Spot Monitor Sensor Left, Faulty Blind Spot Monitor Sensor Right. 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: U1331 indicates Software Incompatibility with Body Control Module.
Common causes: Common causes include Faulty Main Body ECU (Multiplex Network Body ECU), Faulty Blind Spot Monitor Sensor Left, Faulty Blind Spot Monitor Sensor Right.
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 312

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 Mar 29, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code U1331 Description

This Diagnostic Trouble Code (DTC) is stored when the destination information of the Main Body ECU (Multiplex Network Body ECU) does not match that of the Blind Spot Monitor Sensors.

OBDII Code U1331 - Software Incompatibility with Body Control Module - AutoCodes.com — U1331 Code - Software Incompatibility with Body Control Module

What does this mean?

What are the Possible Causes of the DTC U1331?

Faulty Main Body ECU (Multiplex Network Body ECU)
Faulty Blind Spot Monitor Sensor Left
Faulty Blind Spot Monitor Sensor Right

How to Fix the DTC U1331?

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 U1331 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 U1331 code?

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Need Help with the Code?

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Information for Specific Makes

U1331 Lexus — Software Incompatibility with Body Control Module
U1331 Toyota — Software Incompatibility with Body Control Module

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.