AutoCodes – Hummer – U0102 Hummer

U0102 Hummer Code - Lost Communication With Transfer Case Control Module

Quick Answer

Modules connected to the high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Transfer Case Control Module, Transfer Case Control Module harness is open or shorted, Transfer Case Control Module circuit poor electrical connection. 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 Hummer indicates Lost Communication With Transfer Case Control Module .
Common causes: Common causes include Faulty Transfer Case Control Module, Transfer Case Control Module harness is open or shorted, Transfer Case Control Module circuit poor electrical connection.
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 3,201

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 Jun 29, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U0102 Hummer Description

Modules connected to the high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised, and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module.
The serial data circuit is how the devices in the vehicle communicate with each other. Once the scan tool is connected to the serial data circuit through the Data Link Connector (DLC), the scan tool can be used to monitor each device for diagnostic purposes and to check for Diagnostic Trouble Codes (DTC). When the ignition switch is in RUN, each device communicating on the serial data circuit sends a state of health message to ensure that the device is operating correctly. When a device stops communicating on the serial data circuit, for example, if the device loses power or ground, the state of health message, it normally sends on the serial data circuit disappears. Other devices on the serial data circuit, which expect to receive that state of health message, detect its absence; those devices, in turn, set a DTC associated with the loss of the state of health of the non-communicating device. The DTC is unique to the device which is not communicating, and one or more devices may set the same code. A loss of serial data communications DTC does not represent a failure of the devices that contain the stored code.

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

What does this mean?

What are the Possible Causes of the DTC U0102 Hummer?

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 Hummer?

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

There is a factory service bulletin for the 2008-2009 HUMMER H2:
2008-2009 HUMMER H2 Factory Service Bulletin OBDII Code U0102

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0102 Hummer 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 Hummer code?

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

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Get the U0102 Hummer 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 U0102 Hummer Code

1. What are the common symptoms of OBDII code U0102 in a Hummer related to the Transfer Case Control Module?

The common symptoms include difficulty shifting gears, loss of 4WD functionality, dashboard warning lights related to the transfer case, and in some cases, the vehicle may go into limp mode.

2. What are the possible causes of OBDII code U0102 in a Hummer?

The code U0102 "Lost Communication With Transfer Case Control Module" can be caused by a faulty transfer case control module, damaged wiring or connectors, a blown fuse, or issues with the CAN bus communication network.

3. How can I diagnose the root cause of OBDII code U0102 in my Hummer?

To diagnose the issue, you may need to perform a thorough inspection of the transfer case control module, check the wiring and connectors for any damage, test the fuses related to the transfer case system, and use a diagnostic scanner to check for communication errors on the CAN bus network.

4. Can I continue driving my Hummer with OBDII code U0102 present?

It is not recommended to drive your Hummer with the U0102 code present, as it can lead to further damage to the transfer case system and potentially compromise the vehicle's drivability and safety.

5. How can I repair OBDII code U0102 in my Hummer?

The repair process may involve replacing the transfer case control module if it is faulty, repairing or replacing damaged wiring and connectors, ensuring proper fuse functionality, and reprogramming the control module if necessary.

6. Is it possible to reset the OBDII code U0102 in my Hummer without fixing the underlying issue?

While you can clear the code temporarily with an OBDII scanner, it is crucial to address the root cause of the communication error to prevent the code from reappearing and causing potential issues in the future.

7. Is the repair for OBDII code U0102 in a Hummer a DIY task?

The repair process for the U0102 code can vary in complexity, and it may require advanced diagnostic tools and technical expertise. It is recommended to consult a professional mechanic or dealership for accurate diagnosis and repair.

8. Will OBDII code U0102 in my Hummer cause any long-term damage if left unaddressed?

Leaving the U0102 code unaddressed can potentially lead to further damage to the transfer case system, affecting the vehicle's drivability and safety. It is best to address the issue promptly to prevent any long-term complications.

9. Can extreme weather conditions contribute to triggering OBDII code U0102 in a Hummer?

Extreme weather conditions such as heavy rain, snow, or temperature fluctuations can sometimes affect the transfer case control module's performance and communication, leading to the U0102 code being triggered.

10. How much can I expect to pay for repairing OBDII code U0102 in my Hummer?

The cost of repairing the U0102 code can vary depending on the root cause of the issue, the extent of the damage, and labor costs. It is advisable to obtain quotes from different repair shops or dealerships to determine the overall cost.