AutoCodes – Generic – U1002

U1002 Code - Lost Communication with Gateway 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 Gateway Module, Gateway 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: U1002 indicates Lost Communication with Gateway Module.
Common causes: Common causes include Faulty Controller Area Network (CAN) Communication System, Faulty Gateway Module, Gateway 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 43,404

How popular is this code, among other codes? Medium

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 U1002 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 Gateway Module has not been received.

OBDII Code U1002 - Lost Communication with Gateway Module - AutoCodes.com — U1002 Code - Lost Communication with Gateway Module

What does this mean?

What are the Possible Causes of the DTC U1002?

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

How to Fix the DTC U1002?

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 U1002 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 U1002 code?

Need more information on how to fix the U1002 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1002 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1002 Infiniti — ABS System Communication Controller Area Network
U1002 Lexus — Lost Communication with Gateway Module
U1002 Nissan — ABS System Communication Controller Area Network
U1002 Toyota — Lost Communication with Gateway 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.

Frequently Asked Questions about U1002 Code

1. What are the common symptoms of OBDII code U1002 (Lost Communication with Gateway Module)?

- Common symptoms include the check engine light illuminating, communication issues with various vehicle modules, and possible issues with vehicle systems like the radio or HVAC.

2. What are the possible causes of OBDII code U1002?

- Potential causes include faulty gateway module, damaged wiring or connectors, loose connections, software glitches, or issues with other modules connected to the gateway module.

3. How can I diagnose the reason behind OBDII code U1002 being triggered?

- Diagnosing the issue involves checking for loose or damaged connections, performing a scan with a diagnostic tool to identify which modules are not communicating, and conducting a thorough inspection of the gateway module.

4. Can a DIYer repair OBDII code U1002 at home?

- While some causes like loose connections can be fixed at home, diagnosing and repairing issues related to the gateway module may require specialized tools and expertise, making it advisable to seek professional help.

5. Are there any tips for repairing OBDII code U1002 related to lost communication with the gateway module?

- Tips include checking all connections, ensuring proper grounding, updating software if applicable, and consulting the vehicle's service manual for specific troubleshooting steps.

6. What are the potential risks of ignoring OBDII code U1002?

- Ignoring this code can lead to continued communication issues between vehicle modules, potentially affecting the vehicle's performance, safety systems, and overall reliability.

7. How much does it typically cost to repair OBDII code U1002?

- Repair costs can vary depending on the underlying cause, location, and labor rates, but expect costs to range from a simple connector repair to potentially replacing the gateway module.

8. Can OBDII code U1002 be intermittent or sporadic?

- Yes, this code can sometimes be triggered intermittently due to loose connections or sporadic communication issues, making it important to address the problem promptly.

9. Will resetting the OBDII code U1002 clear the issue permanently?

- Resetting the code may temporarily turn off the check engine light, but if the underlying issue causing the lost communication with the gateway module is not fixed, the code is likely to reappear.

10. Is it safe to continue driving with OBDII code U1002 present?

- It is generally not recommended to drive with this code present, as it indicates potential communication issues that can affect various vehicle systems. It's best to have the issue diagnosed and repaired promptly.