"To properly test the 7mgte AFM, one needs an oscilloscope. I suppose thats why Toyota didn't publish the test procedures in the TSRM. I took my car to a local shop where they hooked up an oscilloscope and checked the wave pattern. Its supposed to be a constant square wave that gets higher frequency as the rpms go up. A bad AFM will show an erratic signal, sometimes just flatline or much lower frequency than normal. The test in the TSRM is just for air temperature". I have not tried this as i dont have an oscilloscope at the moment. hope this works for someone that has one.
