Yeah I’m sure it shouldn’t be there and maybe it reads a low voltage every time the truck is started or turned off. Or maybe it throws a code and it never gets erased. Like I say, I always ignore it.

 

My check engine lite is on permantly. I put an external voltage regulator on (I think per your suggestion) so the light is stuck on (a resistor to fake it out does not work). I wonder how long before the light burns out??

 

I would think, that if you left the PCM connector hooked up to the alternator, even though it wasn't controlling it, it would still fool the PCM into thinking things were working as they should?

 

I dunno. Maybe you’re right. I just followed the guy’s instructions. He included a resistor (I think it was 80 ohms) with the voltage regulator to try and fake out the ECM to turn the light out. It didn’t work. On the other hand, I’m throwing a code 41 and 46 that I can’t get rid of so maybe that keeps it on. My memory sucks these days but it seems to me that 41 and 46 came a bit after I put the ext regulator on with the resistor. I just remember I was disappointed the light didn’t go off. The guy said it doesn’t always turn off the light.

How much can it hurt to try?

 

On a tangent to this ... I would LOVE to find the files to feed MPTune for our ECUs. (Well, for mine at least!)

One of these days I'm going to learn 68xx family assembly and see if I can rip apart the code base so I can do things like, well, comment out the regulator portion to kill the 41 and 46 codes. So I can run an external regulator if I wish.

RwP

 

This planet needs people like you. You're willing to learn seldom-used stuff that others are unwilling to do. Like me.

You'll crack Enigma codes while I try to figure out how to replace the CHECK ENGINE bulb when it burns out.