A vehicle may set a crank/cam correlation code even though both sensors produce clean signals. The ECU is not necessarily saying either sensor is dead. It is saying the expected timing relationship between them has shifted.
Possible causes include a stretched timing chain, jumped belt, damaged reluctor, incorrectly installed cam phaser, VVT actuator stuck in the wrong position or a sensor target that has moved. A scope capture comparing crank and cam edges is powerful because it shows whether the electrical signals are present and whether their phase relationship matches a known-good pattern.
Scan data can also help. Look at commanded versus actual cam angle, synchronization status and whether the fault appears only during VVT operation. If base mechanical timing is wrong, replacing sensors will not restore correlation.
The lesson applies broadly: correlation codes are invitations to compare systems, not instructions to buy the first sensor named.
Figure: Correlation Case Study: Crank, Cam and Mechanical Timing