AutoCodes – Chevrolet – U1817 2018 Chevrolet Silverado

U1817 2018 Chevrolet Silverado Code - Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction

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 Starter/Generator Control Module, Starter/Generator Control Module harness is open or shorted, Starter/Generator 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: U1817 2018 Chevrolet Silverado indicates Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction.
Common causes: Common causes include Faulty Starter/Generator Control Module, Starter/Generator Control Module harness is open or shorted, Starter/Generator 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 202

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 Jul 24, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1817 2018 Chevrolet Silverado 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 Motor Control Module and the Hybrid Powertrain Control Module are all internal to the Starter/Generator Control Module. All circuits to the Hybrid Powertrain Control Module are also internal to the Starter/Generator Control Module.
Communication diagnostics for the serial data, including device power and ground as well as the wakeup circuits for the Motor Control Module and the Hybrid Powertrain Control Module are all diagnosed from external sources only to the Starter/Generator Control Module connector because any circuit fault condition within the Starter/Generator Control Module will cause a complete replacement.
The Diagnostic Trouble Code (DTC) will be set when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U1817 2018 Chevrolet Silverado - Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction - AutoCodes.com — U1817 2018 Chevrolet Silverado Code - Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction

What does this mean?

What are the Possible Causes of the DTC U1817 2018 Chevrolet Silverado?

Faulty Starter/Generator Control Module
Starter/Generator Control Module harness is open or shorted
Starter/Generator Control Module circuit poor electrical connection

How to Fix the DTC U1817 2018 Chevrolet Silverado?

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 U1817 2018 Chevrolet Silverado 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 U1817 2018 Chevrolet Silverado code?

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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 U1817 2018 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code U1817 on a 2018 Chevrolet Silverado?

- Common symptoms include the check engine light illuminating, loss of communication with the hybrid powertrain control module, and potential drivability issues.

2. What does the U1817 code "Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction" mean?

- This code indicates a communication problem between the vehicle's powertrain control module and the hybrid powertrain control module on the Powertrain Expansion Controller Area Network (CAN) bus.

3. What are some possible causes of U1817 code on a 2018 Chevrolet Silverado?

- Possible causes include wiring issues, damaged connectors, faulty control modules, software glitches, or issues with the Powertrain Expansion CAN bus.

4. How can I diagnose the U1817 code on my 2018 Chevrolet Silverado?

- Diagnosing the U1817 code may involve checking the wiring and connectors for damage, testing the control modules, performing a CAN bus communication test, and using a scan tool to retrieve specific diagnostic information.

5. Can I still drive my Chevrolet Silverado with the U1817 code present?

- It is not recommended to drive the vehicle with the U1817 code active, as it can lead to potential drivability issues and affect the performance of the hybrid powertrain system.

6. How can I repair the U1817 code on my 2018 Chevrolet Silverado?

- Repair options may include repairing or replacing damaged wiring, addressing connector issues, reprogramming control modules, or consulting a professional technician for further diagnosis and repair.

7. Will resetting the trouble codes make the U1817 code go away?

- Resetting the trouble codes may temporarily clear the check engine light, but the U1817 code will likely reappear if the underlying communication issue between control modules is not addressed.

8. Is the U1817 trouble code specific to the hybrid powertrain system in the Chevrolet Silverado?

- Yes, the U1817 code specifically relates to communication problems with the hybrid powertrain control module on the Powertrain Expansion CAN bus in the 2018 Chevrolet Silverado.

9. Can a DIY enthusiast fix the U1817 code issue, or should I seek professional help?

- While some basic checks like inspecting wiring and connectors can be done by a DIY enthusiast, diagnosing and repairing complex communication issues related to the U1817 code may require professional expertise.

10. How can I prevent the U1817 code from occurring in the future?

- To prevent the U1817 code, regular maintenance checks, avoiding water damage to control modules, ensuring proper wiring connections, and promptly addressing any warning lights can help maintain the vehicle's communication systems.