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Engine-Codes – Nissan – U1003 Nissan

U1003 Nissan Code - Lost Communication With VVEL Control Module

Quick Answer

The U1003 diagnostic trouble code for Nissan vehicles indicates that there is a communication issue with the VVEL (Variable Valve Event and Lift) control module. Common causes include Loose or corroded wiring connections, Faulty VVEL control module, Malfunctioning engine control module (ECM). 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 Nissan indicates Lost Communication With VVEL Control Module.
Common causes
Common causes include Loose or corroded wiring connections, Faulty VVEL control module, Malfunctioning engine control module (ECM).
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 09, 2024
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Code U1003 Nissan Description

The U1003 diagnostic trouble code for Nissan vehicles indicates that there is a communication issue with the VVEL (Variable Valve Event and Lift) control module. The VVEL system is responsible for controlling the variable valve timing and lift in the engine, which plays a crucial role in optimizing performance, fuel efficiency, and emissions. When communication with the VVEL control module is lost, it can lead to various issues with engine performance, efficiency, and overall drivability.

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

Common Causes of U1003 Nissan

  1. Loose or corroded wiring connections
  2. Faulty VVEL control module
  3. Malfunctioning engine control module (ECM)
  4. Communication network issues within the vehicle
  5. Electrical interference or signal disruption

Symptoms of U1003 Nissan

  1. Lack of power or acceleration
  2. Rough idling or engine vibrations
  3. Stalling or difficulty starting the engine
  4. Reduced fuel efficiency
  5. Engine misfires or hesitation during acceleration

How to Fix U1003 Nissan

  1. Begin by conducting a thorough inspection of the wiring connections related to the VVEL control module to check for any loose or damaged wires.
  2. Test the VVEL control module and the engine control module (ECM) for proper functionality using a diagnostic scanner to identify any faults.
  3. Check the vehicle's communication network to ensure there are no issues with connectivity or signal interference.
  4. If necessary, replace the faulty VVEL control module or repair any damaged wiring connections to restore communication between the modules.
  5. Clear the diagnostic trouble codes stored in the ECM and test drive the vehicle to confirm that the issue has been resolved.

Cost to Fix U1003 Nissan

The typical repair costs for addressing a U1003 code related to a lost communication with the VVEL control module can vary depending on the specific cause of the issue. In general, the cost of parts for replacing a VVEL control module can range from $200 to $500, while labor costs can range from $100 to $300. Overall, the total repair cost for this issue may fall between $300 and $800, including parts and labor.

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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 U1003 Nissan Code

1. What does the OBDII code U1003 mean on a Nissan?

U1003 indicates a "Lost Communication With VVEL Control Module," meaning the vehicle’s main control systems are not receiving communication from the Variable Valve Event & Lift (VVEL) control module.

2. What are common symptoms of the U1003 code on a Nissan?

Symptoms may include poor engine performance, reduced power, rough idling, stalling, or the Check Engine Light being illuminated.

3. What causes the U1003 code to appear on a Nissan vehicle?

Common causes include a faulty VVEL control module, wiring issues like damaged or corroded harnesses, poor electrical connections, or issues with the CAN (Controller Area Network) communication system.

4. Can I still drive my Nissan with the U1003 code active?

While the car may still drive, continued operation can lead to reduced performance, potential engine damage, or unsafe driving conditions. It’s best to address the issue promptly.

5. How do I diagnose the U1003 code on a Nissan?

Start by scanning for codes with a diagnostic tool. Inspect the VVEL control module, wiring, and connectors for damage or corrosion. Check the CAN communication system for faults.

6. How can the U1003 code be repaired on a Nissan?

Repairs may involve fixing or replacing damaged wiring, cleaning corroded connectors, reprogramming the VVEL control module, or replacing the faulty module if necessary.

7. Is the U1003 code specific to certain Nissan models?

While it can occur in various Nissan models, it is more commonly found in those equipped with VVEL systems, such as certain Infiniti and Nissan performance vehicles.

8. Can a weak battery cause the U1003 code on a Nissan?

Yes, a weak or failing battery can cause communication errors, including U1003, by disrupting the electrical supply to the VVEL control module.

9. What tools are needed to fix the U1003 code on a Nissan?

You’ll need an OBDII scanner, a multimeter for testing electrical connections, and potentially a specialized tool for reprogramming or resetting control modules.

10. How much does it cost to fix the U1003 code on a Nissan?

Repair costs can vary depending on the exact issue. Simple wiring repairs may cost under $200, while replacing the VVEL control module could cost $1,000 or more, including labor.

Discuss the causes and fixes for U1003 Nissan OBDII Code

Submit a New Comment

  • The VVEL relay and the VVEL module so far. I have cleaned all fuses and connection as I can see.
    still starts in Limp mode with error P1606 and U1003 codes.

    Reply to Comment

  • Let me check if I can find more information. What model and year is your Nissan?

    Reply to Comment