2014 Hyundai Veloster – Start and Stall, Cold or after sitting for 2 hours – P0340 intake cam shaft position ‘circuit fault’

Every now and then a vehicle comes in with a weird issue that you have to be creative and work out a new test method for working out the plan for repair,

The vehicle, came in with a fault code
P0340 Intake camshaft position (CMP) sensor ‘A’ circuit (Bank 1 or single sensor) Pending
the vehicle when cold would start and then stall, if restarted the vehicle would fire up and run with no issue at all,

Live Data was checked and it was foudn that the Live Data Pid for cam synchronisation would say yes and then in the next framde say no, which ment the vehicle, cut fuel and shut down, This was captured.

To confirm this the lab scope was brought out to confirm what was happening on the ECU Processed live data was what was HAPPENING AT THE sensors.

The Scope data revealed that the intake cam shaft missed a pulse output during cranking the first time it had not been started for more than 2 hours.

below the picture shows the differences, between starting and stalling and starting and staying running.

camshaft un synchronisation after sitting for 2 hours
Intake cam missing one signal when starting for first time after 2 hours
Intake cam correct and vehicle running

What to do next is Strip the engine down and inspect the timing chain and cam phasers and retest.