U1817 GMC 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 GMC 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 GMC 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 GMC?
- 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 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 U1817 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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Information for Specific GMC Models
- U1817 2014 GMC Sierra — Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction
- U1817 2015 GMC Sierra — Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction
- U1817 2016 GMC Sierra — Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction
- U1817 2017 GMC Sierra — Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction
- U1817 2018 GMC Sierra — Lost Communication with Hybrid Powertrain Control Module on Powertrain Expansion CAN Bus Malfunction
Frequently Asked Questions about U1817 GMC Code
1. What are common symptoms of U1817 GMC code?
Common symptoms include the hybrid powertrain system not functioning properly, issues with the powertrain control module, and potential loss of power or efficiency in the vehicle.
2. What can cause the U1817 GMC code to appear?
The code U1817 can be triggered by a malfunction in the powertrain expansion CAN bus, communication problems with the hybrid powertrain control module, or faults in the wiring or connectors related to these components.
3. How do I diagnose the U1817 GMC code?
Diagnosing the U1817 code typically involves using a diagnostic scanner to check for communication errors between the powertrain control module and the hybrid powertrain control module. It may also involve inspecting the wiring and connectors for any signs of damage.
4. What are some repair tips for fixing the U1817 GMC code?
Repair tips for U1817 may include checking and repairing any damaged wiring or connectors, resetting the fault codes after fixing the issue, and ensuring proper communication between the powertrain control module and the hybrid powertrain control module.
5. Can I drive my vehicle with the U1817 GMC code?
It is not recommended to drive your vehicle with the U1817 code present, as it can lead to further damage to the hybrid powertrain system and potentially affect the vehicle's performance and safety.
6. How serious is the U1817 GMC code?
The U1817 code should be addressed promptly as it indicates a malfunction in the hybrid powertrain control module communication, which can impact the overall performance and efficiency of the vehicle.
7. Will resetting the U1817 GMC code make it go away permanently?
Resetting the U1817 code may clear it temporarily, but if the underlying issue causing the code is not addressed, it is likely to reappear. It is important to diagnose and repair the root cause of the code to prevent it from coming back.
8. Can a DIY enthusiast fix the U1817 GMC code?
While some basic troubleshooting steps can be performed by a DIY enthusiast, diagnosing and repairing the U1817 code may require advanced diagnostic tools and knowledge. It is recommended to consult a professional mechanic for proper diagnosis and repair.
9. How much does it cost to fix the U1817 GMC code?
The cost of fixing the U1817 code can vary depending on the underlying cause of the issue, the extent of the repairs needed, and the labor rates in your area. It is best to get a diagnosis from a mechanic to determine the exact cost.
10. Is the U1817 GMC code a common issue in GMC vehicles?
The U1817 code specific to GMC vehicles may not be as common as some other OBDII codes, but it can occur due to communication issues in the hybrid powertrain system. Regular maintenance and prompt repairs can help prevent this code from appearing.
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