Engine-CodesInfiniti – U1003 Infiniti

U1003 Infiniti Code - Lost Communication With VVEL Control Module

Quick Answer

The U1003 diagnostic trouble code for Infiniti vehicles indicates that there is a communication failure between the vehicle's Engine Control Module (ECM) and the Variable Valve Event and Lift (VVEL) control module. Common causes include Faulty wiring harness: A damaged or corroded wiring harness can disrupt the communication between the ECM and VVEL control module, Loose electrical connections: Loose connections at the ECM or VVEL control module can lead to intermittent communication issues, Defective VVEL control module: A malfunctioning VVEL control module can prevent the ECM from properly controlling valve timing and lift. 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
U1003 Infiniti indicates Lost Communication With VVEL Control Module.
Common causes
Common causes include Faulty wiring harness: A damaged or corroded wiring harness can disrupt the communication between the ECM and VVEL control module, Loose electrical connections: Loose connections at the ECM or VVEL control module can lead to intermittent communication issues, Defective VVEL control module: A malfunctioning VVEL control module can prevent the ECM from properly controlling valve timing and lift.
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.
Table of contents Created and updated by William Orellana on Sep 07, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code U1003 Infiniti Description

The U1003 diagnostic trouble code for Infiniti vehicles indicates that there is a communication failure between the vehicle's Engine Control Module (ECM) and the Variable Valve Event and Lift (VVEL) control module. The VVEL system is responsible for controlling the intake valve timing and lift, optimizing engine performance and fuel efficiency. When communication is lost between the ECM and the VVEL control module, it can lead to a variety of performance issues and potentially affect the vehicle's drivability.

OBDII Code U1003 Infiniti - Lost Communication With VVEL Control Module
U1003 Infiniti Code - Lost Communication With VVEL Control Module

Common Causes of U1003 Infiniti

  1. Faulty wiring harness: A damaged or corroded wiring harness can disrupt the communication between the ECM and VVEL control module.
  2. Loose electrical connections: Loose connections at the ECM or VVEL control module can lead to intermittent communication issues.
  3. Defective VVEL control module: A malfunctioning VVEL control module can prevent the ECM from properly controlling valve timing and lift.
  4. ECM software update: In some cases, a software update for the ECM may be required to address communication issues between the modules.
  5. ECM failure: A failure of the ECM itself can also result in a loss of communication with the VVEL control module.

Symptoms of U1003 Infiniti

  1. Engine misfires or rough idling: A loss of communication with the VVEL control module can lead to incorrect valve timing, resulting in engine misfires or rough idling.
  2. Decreased fuel efficiency: Without proper control of the VVEL system, the engine may not operate at optimal efficiency, leading to decreased fuel economy.
  3. Loss of power: The VVEL system plays a crucial role in optimizing engine performance, so a communication failure can result in a noticeable loss of power during acceleration.
  4. Illuminated Check Engine Light: The U1003 code will trigger the Check Engine Light to illuminate on the dashboard, indicating a problem with the communication between the ECM and VVEL control module.

How to Fix U1003 Infiniti

  1. Diagnose the issue: Use a diagnostic scan tool to retrieve the trouble code and perform a thorough inspection of the wiring harness and electrical connections.
  2. Check for loose connections: Ensure that all electrical connections at the ECM and VVEL control module are securely fastened.
  3. Test VVEL control module: Test the VVEL control module for functionality and replace if necessary.
  4. Repair or replace wiring harness: Repair any damaged wiring or replace the harness if it is beyond repair.
  5. Perform ECM software update: If required, update the ECM software to ensure proper communication with the VVEL control module.

Cost to Fix U1003 Infiniti

The cost of repairing a U1003 code on an Infiniti vehicle can vary depending on the specific cause of the communication failure. In general, the cost of parts such as a new VVEL control module or wiring harness can range from $200 to $500, while labor costs at an auto repair shop can add an additional $100 to $300. Overall, the total repair cost for addressing a U1003 code may fall in the range of $300 to $800. It's important to note that diagnostic time and labor rates at auto repair shops can vary, so it's advisable to check with local shops for a more accurate estimate based on your location and vehicle model.

Need more information about the U1003 Infiniti code?

Need more information on how to fix the U1003 Infiniti code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1003 Infiniti code diagnosed by a professional: Find a repair shop in your area

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 U1003 Infiniti Code

1. What are the common symptoms of OBDII code U1003 in an Infiniti related to lost communication with the VVEL control module?

- Common symptoms include engine misfires, reduced power, stalling, and the illumination of the check engine light.

2. What are some possible causes of OBDII code U1003 in an Infiniti indicating a communication issue with the VVEL control module?

- Possible causes may include a faulty VVEL control module, damaged wiring or connectors, or a communication network issue within the vehicle.

3. How can I diagnose the source of the communication problem with the VVEL control module triggering code U1003 in my Infiniti?

- Diagnosing the issue may involve checking the wiring and connectors for damage, verifying power and ground connections, and using a scan tool to assess communication on the network.

4. Can a DIY enthusiast repair OBDII code U1003 related to lost communication with the VVEL control module in an Infiniti?

- While basic checks like inspecting wiring connections can be done by DIY enthusiasts, resolving complex communication issues often requires advanced diagnostic tools and expertise.

5. Is it safe to drive my Infiniti with OBDII code U1003 present due to a VVEL control module communication problem?

- It is not recommended to drive the vehicle with this code active, as it can lead to performance issues and potential safety risks. Prompt diagnosis and repair are advised.

6. What are some possible repair tips for addressing OBDII code U1003 linked to communication loss with the VVEL control module in an Infiniti?

- Repair tips may include checking and repairing damaged wiring, ensuring proper connections, resetting the code, and retesting to verify the issue has been resolved.

7. Can a software update fix OBDII code U1003 caused by lost communication with the VVEL control module in an Infiniti?

- In some cases, a software update from the manufacturer may address communication issues, so it's worth consulting with a dealership or professional technician for guidance.

8. How does the VVEL control module communicate with other systems in an Infiniti, and what role does it play in the vehicle's operation?

- The VVEL control module communicates with various engine management systems to regulate valve lift and timing, optimizing performance and fuel efficiency in the vehicle.

9. Are there any common issues or known problems with the VVEL control module in Infiniti vehicles that could trigger OBDII code U1003?

- Over time, the VVEL control module may experience internal faults or failures, leading to communication issues that trigger OBDII code U1003.

10. What steps should be taken after resolving OBDII code U1003 related to lost communication with the VVEL control module in an Infiniti to ensure the problem does not recur?

- After repairs, it is recommended to clear the fault code, perform a thorough test drive to confirm the issue is resolved, and monitor the vehicle for any reoccurrence of the code.

Discuss the causes and fixes for U1003 Infiniti OBDII Code

Code U1003 Infiniti comments

No comments found for this page.