ECU trouble??

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Jul 7, 2007
West Chester, Pa
Ok, I found some curious results in my test of the ECU and could use a little advice. These are the results that suspect.

View attachment ECU Diagnoses.pdf

I checked the wiring diagram in the FSM and noticed that the terminals/wires that are suspect (except the T-E1) involve the TPS and the AFM. After realizing this I tested the TPS and AFM and they passed the resistance test in the FSM. The TPS is new as of last year but the AFM is not.

There are no codes but the O2 sensor failed the FSM test.

So where am I now?:confused:

Any advice is appreciated. Jeff
That's a bit too technical for me. You might also try posting on the 3FE Yahoo group. They might have a bit more knowledge of the electronics. Some if not all of those guys should see it here too.
It is not uncommon for the AFM plug/wire to go bad.

I know part of the AFM gets 5 volts(I dont have my fsm anymore) but check the your fsm to see what voltage the plug gets(before the afm of coarse) then check it....check it all
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[hijack]I got a diagnostics box in the mail from you (I think) but don't think it was meant for me.[/hijack]
Another mistake, imagine that.

:meh: Whoops, my resistance reading were off, I didn't disconnect the ECU before doing the resistance tests. I rechecked the voltages for the ECU and still have the trouble areas. I know that some of them are close but the VS terminal, which goes to the AFM, seems the most troubling. It has the same voltage whether the throttle valve is open or closed. I tested the AFM on the truck, passed the test and then took it on the truck to measure the resistance by moving the measuring plate, it moved in a wave pattern just the FSM states. So the TPS sensor and the AFM seem to be good. What do you guys think, do I have a bad ECU?

View attachment ECU Diagnoses.pdf

I'd appreciate any ideas thrown my way. :bang:
I will also post up at the 3EF site to pick as many brains as possible.

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