Error code
OBD2 U0103
OBD2U0103
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
Lost Communication With Gear Shift Module.
Severity
moderateCan drive, but transmission problems may occur.
Summary
U0103 indicates lost communication between the car's data bus and the gear shift module or system relay, typically due to low signal strength.
Symptoms
- Transmission issues
- Check engine light on
Common Causes
- Faulty gear shift module
- Low signal strength in system relay
- Data bus malfunction
Fixes
- Replace faulty gear shift module or system relay
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- U0100Lost Communication With ECM/PCM A
- U0101Lost Communication with TCM
- U0102Lost Communication with Transfer Case Control Module
- U0104Lost Communication With Cruise Control Module
- U0105Lost Communication With Fuel Injector Control Module
- U0106Lost Communication With Glow Plug Control Module
- U0107Lost Communication With Throttle Actuator Control Module
- U0108Lost Communication With Alternative Fuel Control Module
- U0109Lost Communication With Fuel Pump Control Module
- U0110Lost Communication With Drive Motor Control Module
- U0111Lost Communication With Battery Energy Control Module 'A'
- U0112Lost Communication With Battery Energy Control Module 'B'