What does it mean?
U1145 is a Network (CAN bus, module communications) fault code. It indicates: Lost Communication With Keyless Go Security Module .
Symptoms
- Start button does nothing, or the vehicle only starts when the key is held against the backup position
- Doors will not lock or unlock by touching the handle, and the key is reported as not detected
- Keyless entry works intermittently and mainly fails in wet weather
- Alarm sounding at random or refusing to arm
- Immobilizer or key symbol illuminated in the cluster
- The keyless security module is missing from the scan tool module list
Likely causes
- Blown fuse or an open power feed to the keyless security module
- Corroded or damp connector at the module, which is often mounted low in the cabin, under a seat or near the boot area
- Water damage from a leaking seal, blocked drain or a spill reaching the module
- Open or shorted bus wiring between the module and the body control module
- Poor ground connection at the module mounting point
- Weak battery or heavy voltage drop, so the module drops off the network during starting
- Module replaced without being coded and matched to the vehicle, or an internal module failure
How to fix it
- Try the emergency start method described for the vehicle to confirm whether the immobilizer function still works at all
- Check the key fob battery and try the spare fob before investigating the network
- Check the module fuse and measure supply voltage and ground at its connector under load
- Remove the trim and inspect the module and its connector for water marks, corrosion and green terminals, tracing any leak that is found
- Measure the bus lines at the module connector and compare them with a module that is communicating
- Repair the wiring or connector, dry the area and cure the source of the leak
- Replace the module only when supply, ground and bus lines test good, and complete the required coding and key matching afterwards