Also I should note that neither of the 5 volt reference circuits are showing 5 volts. I actually clipped them so I can try to isolate the short and neither circuit appears to be shorted at this time.
I think its time to open the PCM to check the 5 Volt circuit. This is now leaving my area of comfort. Wish me luck!
The article I wrote on how to locate a short-to-ground using a lab scope (November 2015) did not cover how to diagnose a computer’s 5V reference circuit that’s shorted to ground. One of the technicians I work with asked me how I would approach and troubleshoot this type of problem. The 5V...
New computer has arrived. I am re inspecting and wrapping the entire harness, re testing all sensors and wire wheeling all grounds (again) before I give her a go. If THIS doesn't work I will be looking to sell a 1998 cherokee shell with severe burn damage 😅😅
She runs BEAUTIFULLY!
Just for fun I did some probing and found that the 5 volt reference should show 5 volts even with both lines cut. So for future I'll not to simply cut both 5 volt reference wires from both the Black and White PCM connectors and test for a 5 volt signal for confirmation that PCM is supplying it in the first place.
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