Electrically latching rocker arm assembly having built-in OBD functionality

A method of providing diagnostic information for a rocker arm assembly, the method comprising:

• providing the rocker arm assembly with an electromagnetic latch assembly comprising a solenoid mounted to a rocker arm of the rocker arm assembly, wherein the rocker arm has a range of motion;
• mounting a coil to a component distinct from the rocker arm assembly in a position where the coil is inductively coupled with the solenoid such that a magnitude of the inductive coupling varies as the rocker arm moves through the range of motion;
• driving the coil;
• monitoring a circuit comprising the solenoid for a current or a voltage resulting from driving the coil;
• and
• analyzing the current or the voltage to obtain diagnostic information relating to a position of the rocker arm.

A method of providing diagnostic information for a rocker arm assembly, the method comprising:

• providing the rocker arm assembly with a latch pin that translates between a first position and a second position and a solenoid operative to actuate the latch pin, wherein the solenoid has an electrical response characteristic that varies with latch pin position as the latch pin translates between the first position and the second position;
• driving a circuit comprising the solenoid to actuate the latch pin from the first position to the second position;
• measuring a current or a voltage in the circuit to obtain data;
• analyzing the data to obtain diagnostic information relating to location of the latch pin or position of the rocker arm.