AutoCodes – Toyota – B156C Toyota

B156C Toyota Code - Extension Module Disconnected

Quick Answer

The Stereo Component Tuner Assembly and the Radio and Display Receiver Assembly (or Navigation Receiver Assembly) are connected by the USB communication line. Common causes include Faulty Radio and Display Receiver Assembly (or Navigation Receiver Assembly), Faulty Stereo Component Tuner Assembly, Radio and Display Receiver Assembly harness is open or shorted. 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: B156C Toyota indicates Extension Module Disconnected.
Common causes: Common causes include Faulty Radio and Display Receiver Assembly (or Navigation Receiver Assembly), Faulty Stereo Component Tuner Assembly, Radio and Display Receiver Assembly harness is open or shorted.
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 1,265

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 Mar 25, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B156C Toyota Description

The Stereo Component Tuner Assembly and the Radio and Display Receiver Assembly (or Navigation Receiver Assembly) are connected by the USB communication line. When an USB communication error occurs between the Stereo Component Tuner Assembly and the Radio and Display Receiver Assembly (or Navigation Receiver Assembly), this Diagnostic Trouble Code (DTC) will be stored.

OBDII Code B156C Toyota - Extension Module Disconnected - AutoCodes.com — B156C Toyota Code - Extension Module Disconnected

What does this mean?

What are the Possible Causes of the DTC B156C Toyota?

Faulty Radio and Display Receiver Assembly (or Navigation Receiver Assembly)
Faulty Stereo Component Tuner Assembly
Radio and Display Receiver Assembly harness is open or shorted
Radio and Display Receiver Assembly circuit poor electrical connection

How to Fix the DTC B156C Toyota?

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 B156C Toyota 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 B156C Toyota code?

Need more information on how to fix the B156C Toyota code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B156C Toyota code diagnosed by a professional: Find a repair shop in your area

Information for Specific Toyota Models

B156C 2013 Toyota RAV4 — Extension Module Disconnected
B156C 2014 Toyota RAV4 — Extension Module Disconnected
B156C 2015 Toyota RAV4 — Extension Module Disconnected
B156C 2016 Toyota RAV4 — Extension Module Disconnected
B156C 2017 Toyota RAV4 — Extension Module Disconnected
B156C 2018 Toyota RAV4 — Extension Module Disconnected

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 B156C Toyota Code

1. What does OBDII code B156C mean on a Toyota?

B156C indicates that the extension module, part of the vehicle's communication system, is disconnected or experiencing a fault.

2. What are the symptoms of code B156C in a Toyota?

Common symptoms include a malfunctioning infotainment system, loss of certain vehicle communication features, or warning messages on the dashboard.

3. What causes the B156C code to appear?

The code is typically triggered by a loose or disconnected wiring harness, a faulty extension module, or an internal communication failure.

4. Can driving with code B156C damage my Toyota?

While it may not directly harm the vehicle, it can impair functionality, such as communication features or diagnostics, and should be addressed promptly.

5. How do I diagnose the B156C code on a Toyota?

Start by inspecting the wiring and connectors for the extension module. Use a scan tool to check for related codes and verify module communication.

6. How do I fix code B156C in a Toyota?

Reconnect any loose connectors, repair damaged wiring, or replace the faulty extension module if necessary. Clear the code and test the system.

7. What tools are needed to troubleshoot the B156C code?

A scan tool, multimeter, and basic automotive tools are typically required for diagnosing and repairing this issue.

8. Is the B156C code covered under warranty in a Toyota?

It may be covered if your vehicle is under factory warranty or if the issue is related to a recall. Check with your dealership for details.

9. How much does it cost to fix the B156C code on a Toyota?

Repair costs vary depending on the root cause. Reconnecting a loose wire may cost nothing, while replacing a module could cost several hundred dollars.

10. Can I reset the B156C code without fixing the problem?

You can clear the code with a scan tool, but it will likely return if the underlying issue isnâ€™t resolved.