Maintenance
The Key Case That Stopped the Van Starting
A replacement key shell worked the central locking but left the immobiliser unhappy.
The symptom
After changing the key case, the remote still unlocked the van but the engine refused to start. The dashboard showed the car-and-key immobiliser warning.
The fix
The immobiliser transponder was still attached to part of the original key casing. Refitting that section restored normal starting immediately.
Lesson learned
A key can operate the remote central locking while still missing the separate transponder needed by the immobiliser.