AFM Plug Wire Locations

bioskyline

New Member
Oct 21, 2010
1,236
0
0
powell river bc
ill look on mine tommorow in the daylight, but i dont think it really matters iirc, the brown are just ground wires so i dont think it will matter if you hook them up wrong

edit: ok im looking at the tsrm....they are grounds but they do seem to matter. ill trace them and be sure. one goes to the check connector at E1 the other goes to like 4 other systems and the tccs.
 
Last edited:

CyFi6

Aliens.
Oct 11, 2007
2,972
0
36
Phoenix
www.google.com
I know this is an old thread, but is it alright for both the karman vortex unit and the air temp sensor to be grounded to the ECU sensor ground (pin E2)? I suppose it wouldn't be a problem but then again, Toyota ran two different grounds, probably for a particular reason that I can't think of.
 

CyFi6

Aliens.
Oct 11, 2007
2,972
0
36
Phoenix
www.google.com
K thanks JJ. Any idea why the AFM is chassis grounded? Either there's a lot more going on in there than the schematic illustrates or I just don't understand how it works. It looks as if vref comes in, goes through a diode, then goes strait to ground, without anything else using the vref.
 
Last edited:
Oct 11, 2005
3,815
13
38
Thousand Oaks, CA
Ks is a digital signal, and any good designer will be careful to keep his analog grounds separate from the noisy digital grounds. Treat the "schematic" shown on the symbol as notional, it does not represent in any true way what is going on.
 

CyFi6

Aliens.
Oct 11, 2007
2,972
0
36
Phoenix
www.google.com
Intuitively I would think the battery/chassis ground would be more noisy than the E2 sensor ground, is this incorrect? Do you think it is important to keep them separate or would it make a negligible difference?
 
Oct 11, 2005
3,815
13
38
Thousand Oaks, CA
That is correct E1 is noisier than E2. The analog THA signal is referenced to the clean E2 ground. The digital Ks AFM signal is referenced to the noisier E1, since Ks has a much higher noise margin.