Can someone explain the *CMs to me?

[SouthernGorilla]

There are too many computers in cars these days. Can someone explain the roles of the different black boxes to me? I understand that IPM is basically a fancy name for a fuse box. And the FCM seems to be responsible for the lights up front. Would my truck even have a BCM since it has no power accessories? Does a manual truck still have a PCM or do they call it an ECM instead?

 

[buddy guy]

My 2018 doesn't have any power stuff either aside from radio, engine, gauge related but it does have a Body Control Module. My factory dealer added on remote start goes through it though. not sure what else. but it's there and probably there on any of the trucks in case you want to modify later, just like there are a lot of harnesses for power seats, remote start already on so its an easy job and quick but good money for the dealership to put on accessories.

 

[buddy guy]

A power-train control module, abbreviated PCM, is an automotive component, a control unit, used on motor vehicles. It is generally a combined control unit, consisting of the engine control unit (ECU) and the transmission control unit (TCU).

 

[SouthernGorilla]

A power-train control module, abbreviated PCM, is an automotive component, a control unit, used on motor vehicles. It is generally a combined control unit, consisting of the engine control unit (ECU) and the transmission control unit (TCU).

Right. But since it isn't controlling my transmission or transfer case, isn't it really just an ECU? Or is it the same box just flashed to ignore the missing inputs?

 

[buddy guy]

beyond my pay grade, my friend

 

[HemiLonestar]

My 2018 doesn't have any power stuff either aside from radio, engine, gauge related but it does have a Body Control Module.

Shiiiit lol, whole lot more modules in that rolling computer network than you think lol.
TIPM
Airbag module(s)
BCM/FCM (depending on year)
PCM
ABS module
The EVIC in the dash cluster is pretty much a module unto itself (used to be in the overhead console in 3rd gens)
Immobilizer module (SKIM)
In some cases door control modules, especially if it has auto up/down windows with the safety stop feature
And so on and so on....
CAN bus vehicles have a fuckload of them lol

Does a manual truck still have a PCM or do they call it an ECM instead?

Still called a PCM because the same module is used whether stick or auto

Or is it the same box just flashed to ignore the missing inputs?

Answered your own question lol

 

[SouthernGorilla]

Answered your own question lol

I merely presented the only two possibilities I could think of. Needed someone to pick the real one.

Also don't know how much of this info is in the service manual. The one I downloaded has over 4,000 pages, not exactly easy to sift through.