I have a 2012 Westminster and it has cut out 2 or 3 times when pulling away from junctions,fault code was B1140-15 Engine Crank Authorisation.
Possible causes
Engine crank authorisation signal circuit short circuit to power or open circuit.
Actions required
Refer to the electrical circuit diagrams and check engine crank authorisation signal

I was going to replace the crank position sensor,do you think this is the best course of action?

If so does anyone know how you get to the sensor?
Looking at engine diagrams it looks like it is behind the starter motor.

Thanks in advance for any help or advice.

Also check any pending codes logged on the IID. They sometimes help further diagnose issues  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
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It’s fully detailed in the W.M.
Mike

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