Bassman780

I will check the other two wires shortly.




Thanks


Joe

tech2

I pm'ed some testing info for you.

Bassman780

Tech2 thanks for the information in the PM greatly appreciate it.


first off I checked the other two wires and they were fine.


I had a Friend come over to help today and we started the process of elimination


EOP is fine
MAP is fine
ACC is fine
AC


got to the AC sensor and did not get 5V at connection I believe <1volt was the reading. Went to the ECM side of it and checked the connections and checked to see if there was 5V coming out of the ECM (no power coming out)


My question is should there be 5V coming out of the ECM going to the sensors, if not is it safe to assume that the ECM is the cause of the open circuit.


Thanks again


Joe

tech2

the ac pressure sensor should have 5 volts from the ecm at key in run. It is a 2 wire connector with a grey/white wire that should have 5volts and a tan low ref grd that goes back to the ecm.


If you don't have 5volts at this sensor and you have done the short to grd check like you did on the oil pressure sender and an ohms check shows no resistance in the circuit (I isolate the circuit and put a load on it to make sure the wires can carry current)...if could be an ecm. The testing procedure is to rule out the wiring, if the wiring is ok, ecm is the next step.

Bassman780

Thanks again. Will load test it this afternoon. But it appears to me that not. having 5 V coming out of the ECM ON THE GRY/whi wire tells me there's a problem with the ECM.

Thoughts?

tech2

the ecm supplies all the sensors 5volts from the same feed wire. if there is 5 volts on the other wires, the ecm is probably fine.

Bassman780

Still having the same problems and at a standstill.

Tech2 sent you a PM with a question.

Thanks

Joe

Bassman780

Update Got to it again yesterday afternoon and checked each 5 volt connection for short

With the key off and the ECM disconnected I set my DMM to ohms setting and found that I had two connectors that gave a reading other then OL. The APP on the 5v ref 2 side (blk/whi wire) showed 4.43 and the CKP also on the 5v ref 2 showed .3-.4 on the meter

My question is does the reading from the APP mean I have a short somewhere in that wire and also would that cause the ref 1 side to show a problem

Thanks in advance for any help

Joe

tech2

I thought the fault was for the 5volt ref 1 circuit?

Bassman780

YUP!!!! That's why I'm completely lost nothing has made sense with this issue from day one. (I went back and checked my notes reviewed any and all Error codes)

I'm going out right now and going to re-test each sensor for voltage, short to ground. Compare all my findings

I have a friend (ford mechanic) helping me and he's stumped too


I'm also going to check the wires coming out of the ECM and see if there is 5 volts coming out (on the connections that showed below 1volt).

They should show 5 volts out of ECM correct?

It is getting close to the " drop back and punt" portion of the repair