Oxygen sensor ECM connector pin #

james5275

Registered User
Hello all,
I'm trying to find the pin number and color codes for the left oxygen sensor signal wire at the ECM connector. According to my haynes manual, it should be pin 43 and the color is tan/red. I did find the wire for the right side-which the haynes is correct. On my 90 SC, pin 43 does have a tan/red wire, but it's about 2 gauge smaller (approx 22ga) than the right (pin 29, approx 18ga). Another important note, pin 43 produces a constant 4 millivolts regardless of engine speed or temp. Is it possible this is the correct wire but the oxygen sensor is bad? Anybody have a ford shop manual or better schematic? For those who must know I am installing an A/F meter. Junk? I'm sure they are, Just need to see it for myself I guess.
I did search here and tccoa with no luck, just found a lot of trash talk about the A/F meters!
Thanks for your help....
JJ
 
garage_attachment.php


maybe this will help you not really sure though this is out of the 1990 EVTM

Chuck
 
Thank you, but thats the same drawing that I have. I find it strange that the left and right circuits would have different size wires. I'm leaning towards a misprint in the schematics, but I will start checking the wires and narrow it down. Thank you again for your help!
JJ
 
Even my 93 EVTM says Pin 44 is right and 43 is left.

Funny, mine shows pin 29 for the right, 43 left. But again, all I have is a typical schematic from haynes applying to all supercharged models. Doesn't yours have the 4 wire sensors? I could also try swapping sensors if checking the pins becomes difficult. Not a lot of room or extra wire down there.
JJ
 
O2 sensor

Checked the right oxygen sensor today and it's not responding properly, picked up a new one tonight, will post results tomorrow.
JJ
 
Found it

For the record,
Wierd but it works, pin 43-right sensor- tan/red. Pin 29-left sensor- tan/orange. First off, my right sensor was bad, giving me erronious reading on what I thought was the left side. After a quick inspection, I found the left sensor unplugged:confused:. All is good now, just waiting for the roads to clear up and take it for a spin. Thanks for everyone's help!
JJ
 
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