Variable speed fuel pumps?

[turbo_bu]

Noticed that on the E38 and E67 ECM's there are variables that deal with variable speed fuel pumps .. PWM controlled fuel pumps it looks like. Ref: {F0580} and {F0581}. On the few vehicles that I looked at, it lists No and the PWM table is all 90% ... thus, the ECM is just commanding the fuel pump to be powered on.

The reason for asking about this "feature" is that many of the aftermarket large fuel pumps use a PWM controller so that the they don't over heat the fuel. It would be nice if the existing ECM had a way of commanding either the controller, or powering directly the fuel pumps using PWM. Didn't know if anyone had played with this, or had tried to make it work. I "think" I read that the Mustangs ECM utilizes PWM for their fuel pump control.

[turbo_bu]

Has anyone seen a tune file where the PWM was set to Yes? I looked at a 2011 CTS-V (figured either the Caddy or the Vette would get it 1st), but it also has F0580 = No.

[izaks]

Raised this earlier, but got no reply.
Cars that DO have PWM pumps and controllers, all show F0580 as NO

[turbo_bu]

Raised this earlier, but got no reply.
Cars that DO have PWM pumps and controllers, all show F0580 as NO

So I'm guessing that GM is doing the usual .... something in the software gets written before the hardware is available to control it. Similar to the ETC. Originally had a TAC module inbetween the ECM and the throttle body. Then, the ECM didn't need the TAC and it controls it directly. Maybe something similar with the PWM fuel pump control???? Currently, ECM talks to the fuel pump controller (sorry, don't remember the acroynmn right now) ... maybe in a few more years, the ECM will be able to drive the fuel pump directly?

[ScarabEpic22]

FPCM (Fuel Pump Control Module) I believe is the acronym you're looking for. :D

There is a good possibility this is the case, or it could completely go unused.