I have been trying to reverse engineer a 2 terminal device and I'm stumped. Its a coil in a car strut. Reads 2.8 ohms and 4 mH with a meter. Neither goes to the metal strut body. The car tests to see if its there right after engine start. I set the scope to capture one trace and got: 12V exponential decay to 5V in 240ms. Scope is on terminal 1. Terminal 2 doesnt show anything, assume its a gnd? The test signal from the controller might switch in a cap or something and measure the decay time as a way of seeing if the R and L is in range. I can plug in a custom wound coil of 2.8 ohms and 4 mH and the darn ecu can tell it aint the factory strut and says 'Adaptive Dynamics Fault'. Like its got eyes or something. Right after this decaying exponential wave form, it gives a 12V 10% 500Hz PWM for a couple hundred ms. During normal operation with the factory strut installed, the PWM is active when the ride height is going up and down, presumably so the pump doesnt have to fight the strut. If you were tasked with designing a network that gave this 240 ms decaying exponential from 12V to 5V, what would be in the parts list? Like I said, I'm stumped. Thanks in advance. Man this is a great forum.