U1817 2017 GMC Sierra 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 2017 GMC Sierra 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.
Code U1817 2017 GMC Sierra Description
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.
What are the Possible Causes of the DTC U1817 2017 GMC Sierra?
- 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 2017 GMC Sierra?
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 2017 GMC Sierra 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 2017 GMC Sierra code?
Need more information on how to fix the U1817 2017 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the U1817 2017 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about U1817 2017 GMC Sierra Code
1. What does the OBDII code U1817 mean on a 2017 GMC Sierra?
The U1817 code indicates a loss of communication with the Hybrid Powertrain Control Module on the Powertrain Expansion CAN Bus.
2. What are the common symptoms of the U1817 code?
Symptoms may include a check engine light, reduced engine performance, failure to start, or hybrid system malfunctions.
3. What causes the U1817 code to appear?
Common causes include faulty wiring or connectors, a malfunctioning Hybrid Powertrain Control Module, network communication issues, or a damaged CAN bus line.
4. Can I still drive with the U1817 code active?
Driving with this code is not recommended, as it may lead to reduced performance or prevent the vehicle from operating properly.
5. How is the U1817 code diagnosed?
A technician will use a scan tool to check for communication faults, inspect wiring and connectors, and test the Hybrid Powertrain Control Module for proper function.
6. What repairs are needed to fix the U1817 code?
Repairs may involve replacing damaged wiring, repairing or replacing faulty connectors, or replacing the Hybrid Powertrain Control Module if it is defective.
7. How much does it cost to fix the U1817 code?
Repair costs vary depending on the specific issue but can range from $100 for wiring repairs to over $1,000 if the module needs replacement.
8. Can a weak battery cause the U1817 code?
Yes, a weak or failing 12V or hybrid system battery can sometimes trigger communication issues like the U1817 code.
9. What tools are needed to diagnose the U1817 code?
A professional-grade OBDII scanner capable of reading manufacturer-specific codes and monitoring CAN bus communication is essential.
10. Can the U1817 code clear itself?
The code may clear temporarily if communication is restored, but the underlying issue must be resolved to prevent it from returning.
Discuss the causes and fixes for U1817 2017 GMC Sierra OBDII Code
Code U1817 2017 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
