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U0115 Cadillac 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 Cadillac 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 622

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

What does this mean?

What are the Possible Causes of the DTC U0115 Cadillac?

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 Cadillac?

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 Cadillac 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 Cadillac Code

1. What are the common symptoms of OBDII code U0115 in a Cadillac indicating a lost communication with Engine Control Module 'B'?

- Common symptoms include the check engine light coming on, engine performance issues, stalling, and difficulty starting the vehicle.

2. What are the possible causes of OBDII code U0115 in a Cadillac?

- The possible causes of this code include damaged wiring or connectors, a faulty Engine Control Module (ECM), software issues, or a loose connection.

3. How can I diagnose the issue causing OBDII code U0115 in my Cadillac?

- A thorough diagnostic process involves checking the wiring and connectors for damage, ensuring all connections are secure, and using a scan tool to communicate with the ECM and other modules.

4. Can a DIY enthusiast repair OBDII code U0115 in a Cadillac?

- While checking for loose connections or damaged wiring is something a DIYer can do, diagnosing and replacing a faulty ECM may require professional assistance due to the complexity of the repair.

5. Is it safe to continue driving with OBDII code U0115 in a Cadillac?

- It is not recommended to drive the vehicle with this code present, as it can lead to further issues with engine performance and potentially cause safety concerns.

6. How much does it typically cost to repair OBDII code U0115 in a Cadillac?

- The cost of repairing this code can vary depending on the exact cause of the issue, but it may range from a few hundred to a few thousand dollars, especially if the ECM needs to be replaced.

7. Can a low battery voltage trigger OBDII code U0115 in a Cadillac?

- Yes, a low battery voltage can cause communication issues between modules in the vehicle, which may trigger code U0115. Ensuring the battery is in good condition is essential for proper vehicle operation.

8. Are there any software updates available to address OBDII code U0115 in a Cadillac?

- It is recommended to check with a Cadillac dealership or authorized service center for any available software updates that may help resolve communication issues triggering code U0115.

9. Will resetting the OBDII code U0115 in a Cadillac make it go away permanently?

- Resetting the code may temporarily clear the check engine light, but if the underlying issue causing the communication problem is not addressed, the code is likely to reappear.

10. How can I prevent OBDII code U0115 from occurring in my Cadillac in the future?

- Regular maintenance, checking the electrical connections, and addressing any communication issues promptly can help prevent code U0115 from occurring in the future.