[tomk]

4.7L PCM can't ignore the PS switch. 4.7L wiring harness always has a connector for the PS switch, IIRC it splits out of the big harness at the base of the branch that goes to the engine-oil-pressure sensor.

I'd assume this vehicle would have always been popping a code if the switch wasn't there.. unless it was never driven over 40MPH.

 

[tomk]

what is your build date (the MDH code on your door sticker)?

I don't see any evidence that 03 4.7's were ever built without the switch, but 04 4.7's do NOT have the switch.

 

[tomk]

hm.. my '03 was 594678.. it definitely had the switch..

Do you have a buildsheet for your rig?

 

[tomk]

reading the description of the OBD code in the diagnostic manual, I have my doubts that will fool the PCM.

If you have that wire in your harness, then you should have the switch connector as well; I don't think they'd put in a wire to nowhere..

It is PCM connector C3 pin 30, and also pin 10 in C105 near the PCM (that will be the easier place to get at it)

...tom

 

[tomk]

sorry, clipped you the wrong C105 location drawing.

All 2003 4.7L's have a 4-connector PCM. You should have the wire.. Check C105 to see if it has a dark-blue/orange wire in pin 10..

 

[tomk]

I just wonder where the wire goes.. I can't believe there would be a wire that doesn't at least end up in a disconnected connector..

If you make it to some get-together that I'm also at, ping me and I'll bring a tone-tracker to see if we can figure out where it goes..

The PCM test happens after driving above 40MPH for some amount of time (I forget how long, 30sec I think) .. so drive a bit on the highway to make sure it behaves..


...tom