I would ask anyone who feels comfortable enough with a voltmeter to probe 2 wires on their engine to do so, and fill out the poll with the results.
"How to check the voltage AT the injector harness"
1. Engine off, Key out of ignition
2. Pick any injector, and unplug the wiring harness at the valvecover by pushing in on the metal retainer and pulling the (engine side) harness away from the plug. (pictured above)
3. the pin locations on the harness (pictured) are 1 & 3 are power, and 2 & 4 are grounds.
4. Set your voltmeter to "DC" voltage.
5.. Put one lead of your voltmeter into pin #1 (or #3), and connect the other lead of the voltmeter to ground BUT NOT THE GROUND IN THE HARNESS. Go to any engine ground, anywhere on the block or head, or to the negative post on your battery.
6. Prepare to start the engine by making SURE that nothing you have put on or around the engine can get wrapped up in a belt, fan, etc.
7. Start the engine, and record the voltage shown on the voltmeter.
8. Turn off the engine, and return the wiring to stock.
9. Please come back here and fill out the poll.
Anyone with a scantool (or AutoEnginuity) should compare the value shown under "FICM Voltage" with the reading you took with your voltmeter...
Please DO NOT fill out this poll by simply reading a scantool for "FICM Voltage"...verify the voltage at the injector harness.
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Starting your engine with one injector disconnected WILL set a code for #___ injector fault, but once the injector is plugged back in, the truck will run normally, with no check engine light or performance loss.
thanks~
Dave
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OK, just an update...
It looks like the signals are being "averaged" when you use a voltmeter...so if you see 10Vdc on the voltmeter you will have ~ 20Vdc in reality (confirmed with an oscilloscope).
So if you don't have an o'scope to capture the signals, then (roughly) double what you see with the voltmeter.
Since all of our previous testing was actually done with an oscilloscope, the voltages I requested are accurate...so just double what you see with your voltmeter, and fill out the poll.
thanks~
Dave