AutoCodes – GMC – U0115 GMC

U0115 GMC Code - Lost Communication with Engine Control Module 'B'

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 Engine Control Module 'B', Engine Control Module 'B' harness is open or shorted, Engine Control Module 'B' 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: U0115 GMC indicates Lost Communication with Engine Control Module 'B'.
Common causes: Common causes include Faulty Engine Control Module 'B', Engine Control Module 'B' harness is open or shorted, Engine Control Module 'B' 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 1,212

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
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Code U0115 GMC 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 Diagnostic Trouble Code (DTC) sets when a periodic message from the Engine Control Module 'B' has not been received.

OBDII Code U0115 GMC - Lost Communication with Engine Control Module 'B' - AutoCodes.com — U0115 GMC Code - Lost Communication with Engine Control Module 'B'

What does this mean?

What are the Possible Causes of the DTC U0115 GMC?

Faulty Engine Control Module 'B'
Engine Control Module 'B' harness is open or shorted
Engine Control Module 'B' circuit poor electrical connection

How to Fix the DTC U0115 GMC?

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 U0115 GMC 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.

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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 U0115 GMC Code

1. What are the common symptoms of OBDII code U0115 GMC?

- Common symptoms include engine stalling, rough idling, difficulty starting the vehicle, and illuminated check engine light.

2. What does the OBDII code U0115 GMC signify?

- The code U0115 indicates a communication error between the vehicle's control module and the Engine Control Module 'B'.

3. What are the possible causes of the U0115 GMC trouble code?

- Possible causes include damaged wiring or connectors, a faulty Engine Control Module 'B', a weak battery, or a malfunctioning CAN bus network.

4. How can I diagnose the U0115 GMC code?

- A thorough inspection of the wiring and connectors related to the Engine Control Module 'B' and checking the battery voltage can help diagnose the issue. Using a diagnostic scanner to read the code is also recommended.

5. Can I still drive my vehicle with the U0115 GMC code present?

- It is not recommended to drive the vehicle with the U0115 code present, as it can lead to further damage and potential safety hazards. Immediate attention and repair are advised.

6. How can I repair the U0115 GMC code?

- Repairing the U0115 code may involve repairing or replacing damaged wiring, connectors, or the Engine Control Module 'B'. It is recommended to consult a professional mechanic for proper diagnosis and repair.

7. Are there any DIY tips for fixing the U0115 GMC code?

- DIY tips may include checking and tightening connectors, inspecting wiring for damage, and ensuring the battery connections are secure. However, complex repairs should be done by a qualified technician.

8. How much does it typically cost to repair the U0115 GMC trouble code?

- The cost of repairing the U0115 code can vary depending on the extent of the issue and the specific repairs needed. It is advisable to obtain quotes from different mechanics or repair shops.

9. Can a low battery voltage cause the U0115 GMC trouble code?

- Yes, a weak or low battery voltage can potentially trigger the U0115 code due to insufficient power for proper communication between modules. Ensuring the battery is in good condition is important.

10. Is it necessary to reset the trouble codes after repairing the U0115 GMC issue?

- Yes, it is recommended to clear the trouble codes after repairing the U0115 issue to reset the system and ensure that the problem has been resolved.