AutoCodes – Lexus – U1114 Lexus

U1114 Lexus Code - Lost Communication with Main Switch Module

Quick Answer

The Controller Area Network (CAN) is a standard bus system in vehicles that enables the connection of automotive devices without the need for a host computer. Common causes include Faulty Controller Area Network (CAN) Communication System, Faulty Main Switch Module, Main Switch Module 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: U1114 Lexus indicates Lost Communication with Main Switch Module.
Common causes: Common causes include Faulty Controller Area Network (CAN) Communication System, Faulty Main Switch Module, Main Switch Module 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 532

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 28, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U1114 Lexus Description

The Controller Area Network (CAN) is a standard bus system in vehicles that enables the connection of automotive devices without the need for a host computer. The exchange of operating information and commands among devices is facilitated by pre-programmed information about the required message exchange on the serial data circuits. Communication is carried out using two dedicated wires, known as CAN high and CAN low, with both lines carrying 2.5V when the CAN bus is in idle mode. During the transmission of data bits, the CAN high line increases to 3.75V while the CAN low drops to 1.25V, creating a 2.5V differential between the lines. Since communication relies on a voltage differential between the two bus lines, the CAN bus is NOT sensitive to inductive spikes, electrical fields, or other noise. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Main Switch Module has not been received.

OBDII Code U1114 Lexus - Lost Communication with Main Switch Module - AutoCodes.com — U1114 Lexus Code - Lost Communication with Main Switch Module

What does this mean?

What are the Possible Causes of the DTC U1114 Lexus?

Faulty Controller Area Network (CAN) Communication System
Faulty Main Switch Module
Main Switch Module harness is open or shorted
Main Switch Module circuit poor electrical connection

How to Fix the DTC U1114 Lexus?

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 does this mean?

Code Tech Notes

When there are problems with the way different systems in a vehicle communicate with each other using a technology called Controller Area Network (CAN) communication, Diagnostic Trouble Codes (DTC) are displayed. These codes can be caused by issues with the main bus or branch of the communication network, or with the Electronic Control Units (ECUs) and sensors that make up the different systems. If you see code for both the CAN communication problems and internal or power source problems at the same time, you should focus on fixing the internal or power source problems first.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1114 Lexus 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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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 U1114 Lexus Code

1. What are the common symptoms of OBDII code U1114 on a Lexus related to lost communication with the Main Switch Module?

- Common symptoms include issues with power windows, door locks, and other functions controlled by the Main Switch Module.

2. What are some possible causes for OBDII code U1114 on a Lexus indicating lost communication with the Main Switch Module?

- Possible causes include a faulty Main Switch Module, damaged wiring or connectors, or issues with the vehicle's electronic control system.

3. How can I diagnose the reason behind OBDII code U1114 on my Lexus?

- A thorough inspection of the Main Switch Module, wiring, and connectors is recommended, along with using a diagnostic scanner to retrieve more detailed information about the communication error.

4. Is it safe to drive my Lexus with OBDII code U1114 present?

- It is generally not recommended to drive the vehicle with this code active, as it may indicate underlying electrical issues that can affect the vehicle's operation and safety.

5. Can I reset OBDII code U1114 on my Lexus without addressing the root cause?

- While you can clear the code temporarily, it is important to address the underlying issue causing the communication error to prevent further problems.

6. How complex is it to repair OBDII code U1114 related to lost communication with the Main Switch Module on a Lexus?

- Repairing this code can vary in complexity depending on the specific cause. It may involve replacing the Main Switch Module, repairing wiring, or addressing other electronic system issues.

7. Are there any DIY tips for troubleshooting OBDII code U1114 on a Lexus?

- DIY tips include checking for loose connections, inspecting the wiring for damage, and ensuring the Main Switch Module is functioning properly before seeking professional help.

8. Will OBDII code U1114 on a Lexus affect the vehicle's overall performance?

- While the code itself may not impact performance directly, it can lead to issues with various vehicle functions controlled by the Main Switch Module, affecting overall usability.

9. How much can I expect to pay for repairs related to OBDII code U1114 on a Lexus?

- Repair costs can vary depending on the cause of the communication error and the extent of the repairs needed. It is advisable to consult a professional for an accurate estimate.

10. Can a Lexus dealership help diagnose and repair OBDII code U1114?

- Yes, a Lexus dealership or a qualified automotive technician with experience in electronic systems can diagnose and repair OBDII code U1114 to ensure proper functionality of the Main Switch Module.