Engine management system - MEMS (Ignition coil): Description and operation (page 2 of 2)

FAULT DETECTION - VVC

If the ECM detects any faults with cam period measurement during start up and initial running, the ECM will try and drive the mechanism to minimum cam period.

If the ECM loses the cam period signal during running, the cam period will remain frozen at the last valid period. Engine speed may be limited as low as 5500 rpm depending on cam period when the fault occurred. The engine idle speed will be raised and will remain raised for the rest of the journey.

NOTE: A camshaft period measurement fault will only be recorded by the ECM if the fault is detected at start-up or during initial running. Camshaft period measurement faults are identified using TestBook.