U0103high severityNetwork
Lost Communication with Gear Shift Control Module
on 2006 Mazda Mazda3 2.3L I4 · FWD
What this code means
Cannot communicate with the gear shift module that manages electronic shifter input.
Symptoms
- Shifter inoperative
- Transmission stuck in park
- Shift indicator not matching
- Cannot select gears
Common causes
- Shift module power failure
- CAN bus wiring issue
- Shift module failure
- Shifter cable disconnected
- Fuse blown
Diagnostic steps
- Check shift module fuse
- Test module power and ground
- Inspect CAN wiring
- Check shifter mechanism
- Test shift position switches
Repair notes
Check shift module power supply. Verify shifter mechanism is functional.
Other Network codes on this vehicle
U0001
High Speed CAN Communication Bus
U0002
High Speed CAN Communication Bus Performance
U0003
High Speed CAN Communication Bus (+) Open
U0004
High Speed CAN Communication Bus (+) Low
U0005
High Speed CAN Communication Bus (+) High
U0006
High Speed CAN Communication Bus (-) Open
U0007
High Speed CAN Communication Bus (-) Low
U0008
High Speed CAN Communication Bus (-) High
U0009
High Speed CAN Communication Bus Shorted Together
U0010
Medium Speed CAN Communication Bus