ficm cold vs hot

[mastaking]

i have another question about about my ficm its has me asking why. I have a 2006 f250 diesel in the morning the temp outside is say in the 50's i have a cts monitor the voltage will say any where from 45-47 with the key on no start. As im cranking it over the voltage is still 45-47. Now when its starts the voltage drop fast to about 38-40 after 30 seconds it come back up 48.5 to 49. Its the orginial ficm the truck has 53000 miles. now when the engine is warmed up key on no start the voltage is again 45-47 start it up the voltage is 46-48.5 why does it do it when its cold but not when its warmed up. The battery are good voltage is 12.3 after start up. I was told the ficm is bad by some guys on here saturday but i dont understand why its doesnt do it when the engine is warm up only when the engine is col. thank again guys for all the help

[Dwilcox]

It has to do with the internal power supply in the FICM. My 06 was doing the same thing but dropped as low as 30V on cold mornings. Finally set off the check engine light and set injector voltage low codes so the dealer warranty it.
I was lucky, 1 month till the warranty expired. Next one will be on me and it will be the soon to be released one from BPD.
The new OEM that was installed has held steady at 47.5V - 48V no matter the temp. for the last year that it has been in. about 8000 miles or so.
Replace it before you fry your injectors or it will cost you a bundle more to replace some of them too.
Good luck.

[worldwide73]

Need a new one. Mine was doing the same thing, put a new power supply(half shell) and its back at 48 volts now all the time.

[jimmyv13]

Yup, it's going out....

send it to Ed at ficmrepair.com