What is this wire for ?

The wire is one of 7 from the end of the loom. The other 6 are timing sensor, alternator 1 and 2, ac compressor, knock sensor and vvt sensor.

The wire is one of 7 from the end of the loom. The other 6 are timing sensor, alternator 1 and 2, ac compressor, knock sensor and vvt sensor.