Fuel Injection System's Self-diagnostics

[VulcanJeff]

Anyone ever run the self-diagnostics to discern fuel injection errors? My FI light came on a couple of weeks ago. (I will chronicle those woes in a different thread).

Per the factory manual: pull the ECU, pull the dummy cap to expose the eight underlying terminals, specifically #37 (while leaving the two big black/white connectors connected), jumper terminal #37 to the battery negative terminal and turn on the ignition.

Turning on the ignition is supposed to result in the FI diagnostics kicking off. The FI LED is supposed to blink out the error codes. When I turn on my ignition, all I get is the typical start-up routine: fuel pump energizes, oil pressure and fuel injection LEDs light up etc. The manual says within 3 seconds, the diagnostics begin. My FI LED goes out but never begins to blink any code(s).

I'm using an alligator-clipped jumper between term 37 and battery neg post. I've checked the jumper for continuity. I've tried different jumpers. Terminal #37 is bright/shiny and free of corrosion. Ditto for the battery terminal.

Perhaps worth noting is after I turn on the ignition and the start-up procedure completes, the FI LED goes out, which is what we want it to do! It indicates no faults were found in the FI components. That said, a person could conclude there are no errors for the LED to blink out and maybe that is the reason why I don't see the self-diagnosis kick off.

But not so fast! The factory manual's DFI chapter is very comprehensive. I said on the forum the other day a caveman could do it! Anyway, there is a small section titled "How To Erase Fault Codes". It says "When the repair has been done, the LED light will not show fault codes any more". "But even if the repair has been done, the ignition switch turned OFF, the battery is disconnected, all the fault codes remain in the ECU, which need not be absolutely erased". The English/grammar is a little rough, haha, but I quote it word for word.