OBD-II code · Network
U064D Lost Communication With Trailer Brake Control Switch
The vehicle bus reports loss of communication with smart trailer brake control switch. The driver-adjustable trailer brake gain input is unavailable; trailer braking falls back to default behaviour.
Is it safe to drive with U064D?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyBus wiring open or shorted
- PossibleModule without power or ground
- PossibleModule failed
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–1.5 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Trailer Brake Control Switch, Vehicle Bus Wiring
Related codes
- U064ALost Communication With Hybrid/EV Battery Pack Current Sensor A
- U064BLost Communication With Hybrid/EV Battery Pack Current Sensor B
- U064CLost Communication With Hybrid/EV Battery Pack Current Sensor C
- U064ELost Communication With EGR Cooler Bypass Position Sensor Bank 1
- U064FLost Communication With Intake Manifold Runner Position Sensor Bank 1
- U0650Lost Communication With Exhaust Pressure Control Valve A Sensor/Switch
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.