Popped on on the way to work tonight. Oil pressure and coolant temp were within normal range but the voltage was down. Checking the Battery voltage was at 12.4v. Also I haven't noticed the grids firing today.(it's been plenty cold enough to make them work)

I'm guessing that the Voltage regulation isn't working in the PCM anymore (causing the CEL to light) so I picked up an external regulator on the way to work to install when I get off in the morning.

Anything else I'm missing that might be the cause of the light comming on?

TIA.

 

i cant help with that issue since i didn't even know they had a CEL light or where it is?

 

Left hand dash opening just below the Voltage meter there are 3 windows for lights LH turn, CEL and ???(brain fart at the present time)

 

CEL ????

Ohhhhh! You mean the "Give Me Money Light" on the newer trucks!

 

Check the codes, that will tell you what the trouble is. Most likely the ASD relay is not functioning.

 

Thanks wanna.

Checked the codes. 12 - haven't messed with the bat in quite a while

41- Generator field not switching properly.... Makes me think VR... of course its 3am if you're on GMT-9

 

Swaping the relays makes no difference.....

 

Mine came on, didn't know it had one, I didn't check the codes, but it was the diodes in the alternator. I was still getting 14V but there must have been some ac voltage in there also.

Aaron

 

.......other than it throws code 42 when you leave the ASD unplugged.

I wired up an external regulator and it charges (at 15.2 volts) now and the grids seem to fire but the light is still on.... any Ideas? Still throwing code 12 & 41...

 

i get an intermitent check engine light. when it happens my voltage is low. usually the next day all is fine again... so i dont know what to tell u.

 

A bad alt will set 41.

 

Well, it's not charging on the way to work today.......

Kinda what I was thinking. I'll have to pull it in the AM and get it checked. Mama ain't gonna like it. I assured her that ther was nothing else wrong with the truck after I threw lots of $$$$$ this fall. Oh well....

On the bright side, the external regulator is already mounted and wires run...

 

I had low to zero voltage last winter,no check engine light but it always needed to be jumped to get a start.Turned out to be a bad ground cable.

 

Thanks. I'll double check it. I haven't found anything chaffed open or shorted anywhere else ....

 

funny, my cel came on yesterday after I changed the fuel filter. Didn't know I had one eather. My bat may be low as I have a draw that I have not isolated, and I have not been driving it, except to move stuff around the property. Just seemed odd that it came on after the filter change.