AutoCodes – GMC – U1816 GMC

U1816 GMC Code - Lost Communication With Drive Motor Control Module B On Bus B

Quick Answer

Devices connected to the powertrain high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Drive Motor Control Module B, Drive Motor Control Module B harness is open or shorted, Drive Motor 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: U1816 GMC indicates Lost Communication With Drive Motor Control Module B On Bus B.
Common causes: Common causes include Faulty Drive Motor Control Module B, Drive Motor Control Module B harness is open or shorted, Drive Motor 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 404

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 07, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1816 GMC Description

Devices connected to the powertrain 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 devices. The devices 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 device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device.
The Diagnostic Trouble Code (DTC) will set when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U1816 GMC - Lost Communication With Drive Motor Control Module B On Bus B - AutoCodes.com — U1816 GMC Code - Lost Communication With Drive Motor Control Module B On Bus B

What does this mean?

What are the Possible Causes of the DTC U1816 GMC?

Faulty Drive Motor Control Module B
Drive Motor Control Module B harness is open or shorted
Drive Motor Control Module B circuit poor electrical connection

How to Fix the DTC U1816 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 U1816 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 U1816 GMC Code

1. What are the common symptoms of OBDII code U1816 GMC?

Common symptoms include the Check Engine Light coming on, poor vehicle performance, issues with acceleration, and potential difficulty shifting gears.

2. What does the OBDII code U1816 GMC indicate?

U1816 indicates a communication problem between the vehicle's onboard computer and the Drive Motor Control Module B on Bus B.

3. What are some possible causes of the U1816 GMC code?

Possible causes include damaged wiring or connectors, a faulty Drive Motor Control Module, software issues, or a malfunctioning CAN bus communication system.

4. How can I diagnose the U1816 GMC code?

Diagnosing this code typically involves using a professional OBDII scanner to retrieve the specific details of the code and checking the wiring and connectors associated with the Drive Motor Control Module B on Bus B.

5. How can I repair the U1816 GMC code?

Repairing this code may involve fixing any damaged wiring or connectors, replacing the Drive Motor Control Module if necessary, updating software, or addressing any issues with the CAN bus communication system.

6. Can I drive my vehicle with the U1816 GMC code?

It is generally not recommended to drive the vehicle with this code present, as it can affect performance and potentially lead to further damage if left unresolved.

7. Will resetting the Check Engine Light fix the U1816 GMC code?

Simply resetting the Check Engine Light may temporarily clear the code, but it will likely reappear if the underlying issue causing the communication problem is not addressed.

8. How much does it cost to fix the U1816 GMC code?

The cost of fixing this code can vary depending on the specific cause of the communication problem. It is recommended to consult a professional mechanic for an accurate diagnosis and cost estimate.

9. Can I fix the U1816 GMC code myself?

While some DIY enthusiasts may be able to address simpler causes like loose connectors, diagnosing and repairing more complex issues associated with this code may require professional expertise.

10. How can I prevent the U1816 GMC code from recurring?

Regular maintenance and timely addressing of any related issues, such as damaged wiring or connectivity problems, can help prevent the U1816 code from recurring in the future.