Crankshaft position sensor (left rear of engine block on top of flywheel housing)
I had a PM re this so I will post again. Thanks Oberoi for the extra pix

Remove connector (2 diff types, 2 pin and coax (shown))
Remove torx screw.
Wiggle cps out.
Note: It may be tight due to the hole it slides in not being painted and rust forms. Persevere.
Clean hole and wipe with smear of grease before inserting new.
Some models have an air valve half covering cps making access a little bit harder.