5.4L Excursion idling very rough
Elder User
Joined: Nov 2008
Posts: 668
Likes: 6
From: Northfield, MI
Actually I said: "...and only requires a test light (not a DVOM.)"
The "not a DVOM" is there for a reason, and that is that we need to check for current flow not voltage, which the DVOM is not capable of the way you have it set up.
If you don't have a test light, you can make one out of any small 12v light bulb and some wire if necessary. Don't use a headlight or anything large, just a marker bulb will do.
Again, I think it is unlikely that a PCM would lose two injector drivers simultaneously, but given the checks you have made so far it is something I would check.
Yes, you could disconnect all of the injectors and the PCM connector and check for continuity to ground at each of the injector leads. There should be none.
The PCM on the Excursions was located next to the park brake pedal assembly, with the electrical connector in the engine compartment. I don't remember them being anywhere else until the 6.0 came out.
Jay
