← Back to list

2018 GMC Sierra 1500 5.3L: U101, P0700, and P0634 Diagnostic Codes Explained

Model: 2018 GMC Sierra 1500 Fault Code: P0634 Posted: 2024-07-15 13:54

My 2018 GMC Sierra 1500 with a 5.3L engine is showing three OBD-II diagnostic codes: U101 (Lost communication with Transmission Control Module), P0700 (Transmission Control System MIL Request), and P0634 (PCM/ECM/TCM Internal Temperature Too High). I'm not sure where to begin troubleshooting, as the symptoms seem related. These codes could indicate a communication issue between modules or an internal temperature fault in the powertrain control system. Any guidance on how to diagnose or resolve these issues would be greatly appreciated.

Related fault codes
P0634P0700
Comments (1)
Anonymous 2024-07-15 23:48

Start here for detailed explanations: https://www.obd-codes.com/u101 https://www.obd-codes.com/p0700 https://www.obd-codes.com/p0634 These codes may be interconnected, especially in the 2018 GMC Sierra 1500 with a 5.3L V8, where TCM communication and internal temperature monitoring are critical components.