Diagnostic guide
Key Fob Unlocks the Car but Won’t Start It
The remote opens the doors, but starting is another problem.
Photo: Barry A / Unsplash
Start here
Try the spare and follow the owner’s manual. Working remote buttons do not rule out a starting-system problem.
Our method
- Check the simplest cause.
- Compare a working spare when possible.
- Verify before ordering a replacement.
If the remote buttons work but the vehicle will not start, do not assume the remote-control portion proves the entire key system is healthy.
Possible categories
- Immobilizer/transponder recognition problem
- Push-button-start key detection issue
- Vehicle battery or starting-system issue unrelated to the key
- Damaged or missing transponder after a shell replacement
What to do
Try a spare key if available and follow the owner’s manual emergency-start procedure. If the spare works, focus on the problem key. If neither works, the vehicle itself needs diagnosis before you spend money on another fob.