A system (44) for controlling camshaft (28) phase in an engine (20) with a crankshaft (26), including: an actuator (42) driving a phaser (38) attached to the camshaft (28). The phaser (38) has a first portion (46) in communication with the crankshaft (26), a second portion (48) attached to the camshaft (28) and in communication with the first portion (46), and a third portion (50) attached to the actuator (42) and in communication with the second portion (48). One portion includes a receiver (52), and another portion includes a lock (54) having: a first position (78) where the portions with the receiver (52) and lock (54) can rotate with respect to each other; and a second position (80) where the portions with the receiver (52) and lock (54) are coupled. The lock (54) moves between positions in response to predetermined torque differential between the actuator (42) and camshaft (28).