I deny grump. Most knowledgeable is open to argument. Both are little more than vicious rumors perpetrated by my enemies
Reaper: I meant to check Vc's voltage but as I said that's grasping.
The TRSM has resistance tests, which are fairly worthless, and what Ks voltage will typically be when operating. Since the duty cycle remains near 50% (mine runs at 2.6 vdc) that spec is laughable. You really need to measure frequency and preferably look at the waveform to know the AFM's health for sure and it should be done at the ECU connector.
The TCCS books say 17-22 hz at idle, 42-46 at 2000 rpm and 90-95 at 4000. It's going to vary from engine to engine and whether the car is parked or under load, which AFM housing is on it, tune, ect. Mine (a Lex) outputs 18 hz at idle, 38 at 1500, 50 at 2000, 62 at 2500, 80 at 3000 and 92 hz at 3500 rpm. That's parked with the EFI system tuned. Your engine is not my engine but that'll give a sense of what to look for.
If you decide to measure it off the car the formula for Karman street generators is F = .2 X V/D, where F is frequency, .2 is a constant, V is velocity and D is pillar diameter. You'll need something to measure velocity. All that said I doubt a shifted AFM is your problem unless the laminar flow screen is damaged or the sensing hole plugged. Usually the electronics die outright or are murdered.