AutoCodes – Generic – U0102

U0102 Code - Lost Communication With Transfer Case Control Module

Quick Answer

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Common causes include Check for more codes, Faulty Transfer Case Control Module, Transfer Case Control 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: U0102 indicates Lost Communication With Transfer Case Control Module.
Common causes: Common causes include Check for more codes, Faulty Transfer Case Control Module, Transfer Case Control 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 31,427

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 30, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U0102 Description

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages are needed to be exchanged on the serial data circuits. CAN bus uses two dedicated wires for communication. The wires are called CAN high and CAN low. When the CAN bus is in idle mode, both lines carry 2.5V. When data bits are being transmitted, the CAN high line goes to 3.75V, and the CAN low drops to 1.25V, thereby generating 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 Transfer Case Control Module has not been received.

OBDII Code U0102 - Lost Communication With Transfer Case Control Module - AutoCodes.com — U0102 Code - Lost Communication With Transfer Case Control Module

What does this mean?

What are the Possible Causes of the DTC U0102?

Check for more codes
Faulty Transfer Case Control Module
Transfer Case Control Module harness is open or shorted
Transfer Case Control Module circuit poor electrical connection

How to Fix the DTC U0102?

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 U0102 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 U0102 code?

Need more information on how to fix the U0102 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0102 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U0102 Buick — Lost Communication with Transfer Case Control Module
U0102 Cadillac — Lost Communication With Transfer Case Control Module
U0102 Chevrolet — Lost Communication With Transfer Case Control Module
U0102 Chrysler — Lost Communication With Transfer Case Control Module
U0102 Dodge — Lost Communication With Transfer Case Control Module
U0102 GMC — Lost Communication With Transfer Case Control Module
U0102 Hummer — Lost Communication With Transfer Case Control Module
U0102 Infiniti — Lost Communication With Transfer Case Control Module
U0102 Jeep — Lost Communication With Transfer Case Control Module
U0102 Nissan — Lost Communication With Transfer Case Control 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 U0102 Code

1. What are the common symptoms of OBDII code U0102 (Lost Communication With Transfer Case Control Module)?

- Common symptoms include difficulty shifting gears, loss of 4WD functionality, dashboard warning lights (such as the 4WD light) illuminating, and in some cases, the vehicle going into limp mode.

2. What are the potential causes of OBDII code U0102?

- The code U0102 can be caused by issues such as a faulty transfer case control module, damaged wiring or connectors related to the transfer case control module, a software glitch, or a weak battery causing communication errors.

3. How can I diagnose the cause of OBDII code U0102?

- To diagnose the cause of U0102, start by checking the wiring and connectors related to the transfer case control module for any damage or corrosion. You can also perform a battery voltage test and inspect the transfer case control module for any visible signs of damage.

4. Can a weak battery cause OBDII code U0102 to appear?

- Yes, a weak or failing battery can cause voltage fluctuations and communication errors, leading to the appearance of code U0102. Ensure your battery is in good condition and properly charged to rule out this potential cause.

5. How can I repair OBDII code U0102?

- Repairing code U0102 involves addressing the root cause, which could be replacing a faulty transfer case control module, repairing damaged wiring or connectors, updating software as needed, or ensuring a healthy battery connection.

6. Can I continue driving with OBDII code U0102 present?

- It is not recommended to continue driving with code U0102 present, especially if you are experiencing symptoms like difficulty shifting gears or loss of 4WD functionality. Continuing to drive could potentially cause further damage to the vehicle.

7. Is it safe to reset the OBDII code U0102 and see if it comes back?

- While you can reset the code to see if it reappears, it is crucial to diagnose and address the underlying issue causing code U0102. Ignoring the problem and simply clearing the code without fixing the root cause may lead to more severe issues down the road.

8. How much does it typically cost to repair OBDII code U0102?

- The cost of repairing code U0102 can vary depending on the cause of the issue. Costs may include parts such as a new transfer case control module, labor for diagnostics and repairs, and any additional components or software updates needed.

9. Can a DIY enthusiast fix OBDII code U0102, or should I take it to a professional mechanic?

- While some DIY enthusiasts may have the skills and tools to diagnose and repair code U0102, it is generally recommended to seek the expertise of a professional mechanic, especially when dealing with complex electronic control modules like the transfer case control module.

10. How often does OBDII code U0102 occur in vehicles, and is it a common issue?

- OBDII code U0102 (Lost Communication With Transfer Case Control Module) is not as common as some other codes but can still occur in vehicles with electronic transfer case control systems. Proper maintenance and addressing potential issues promptly can help prevent this code from appearing.