Im a complete novice with the pico (so go easy on me!
) but I got a lend of one last night to check my maf sensor.
I have an old E300td (1999) that is in need of a lot of work. Among other problems I suspect the maf may be faulty and may be contributing to the car being down on power at times. (The vehicle is suffering from various faults that would also cause a low-power condition but I just want to check the maf too before buying one!)
I first checked the air filter and found it to be black so it was replaced. I took some readings with the scope pre air-filter change and post air-filter change. They were exactly the same.
I was hoping someone could take a look to at the post-air-filter-replacement waveform (attached) and see if they spot anything meaningful. The main problem I can see is that its only ranging between approx. 1.5v - 2.45v.
I cannot find a wiring diagram for the engine management on the e300td (om606.962) but basically in this capture I had the scope backprobing the maf signal wire and maf earth wire. (in previous waveforms I took last night I hooked it up between maf signal and an external earth - the waveform was the same, just a bit more 'hash' on the waveform).
The waveform shows the engine at idle, then wide-open throttle, then back to idle.
Id really appreciate any observations you may have on the waveform.