U0243low severityNetwork
Lost Communication with Trailer Hitch Module
on 2005 Mazda MX-5 Miata 1.8L I4 · RWD
What this code means
Cannot communicate with the integrated trailer hitch control module.
Symptoms
- Trailer lights not working
- Trailer brake output disabled
- Tow/haul mode limited
- Trailer sway control disabled
Common causes
- Hitch module failure
- CAN bus wiring
- Module power loss
- Fuse blown
- Trailer connector corrosion
Diagnostic steps
- Check hitch module fuse
- Test power and ground
- Check CAN wiring
- Inspect trailer connector
- Test trailer light outputs
Repair notes
Check fuses and trailer connector. Corrosion at trailer plug is the most common cause.
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