PWM Control of GM Alternators

E38 E92 and many others. Approximately 2007 and newer
User avatar
Tre-Cool
Posts: 533
Joined: Tue Oct 16, 2012 2:17 am
cars: VY SS UTE, VX Drag Car
Location: Perth

Re: PWM Control of GM Alternators

Post by Tre-Cool »

my c6 tends always run at 14.5v, very rarely see it under 13v.
MPC001
Posts: 174
Joined: Sat May 05, 2018 11:41 am

Re: PWM Control of GM Alternators

Post by MPC001 »

Tre-Cool wrote: Sat Dec 06, 2025 1:58 pm my c6 tends always run at 14.5v, very rarely see it under 13v.
Thanks for the feedback. Interesting & appreciated.
User avatar
Knackersjewels
Posts: 155
Joined: Thu May 05, 2022 10:24 am
cars: Stock VZ SV6
Cammed VZ SV6 (sson to be 6L45 converted and twin turbo)
VY SS L98 ute
VZ V6 AWD One Tonner
Location: Maffra, Vic

Re: PWM Control of GM Alternators

Post by Knackersjewels »

I have a pwm alternator on one of my LS vehicles, using P59. Couldn't get it natively controlling it properly, so bought a cheap pulse width controller. 128hz, 92% duty gets around 14.8v from the scanner, and on the gauge, if unplugged, it defaults to 13.5v
MPC001
Posts: 174
Joined: Sat May 05, 2018 11:41 am

Re: PWM Control of GM Alternators

Post by MPC001 »

Knackersjewels wrote: Sat Dec 13, 2025 10:49 am I have a pwm alternator on one of my LS vehicles, using P59. Couldn't get it natively controlling it properly, so bought a cheap pulse width controller. 128hz, 92% duty gets around 14.8v from the scanner, and on the gauge, if unplugged, it defaults to 13.5v
Great feedback thankyou. Is the alternator a regular Holden Mitsubishi unit? (140A IIRC?)
User avatar
Knackersjewels
Posts: 155
Joined: Thu May 05, 2022 10:24 am
cars: Stock VZ SV6
Cammed VZ SV6 (sson to be 6L45 converted and twin turbo)
VY SS L98 ute
VZ V6 AWD One Tonner
Location: Maffra, Vic

Re: PWM Control of GM Alternators

Post by Knackersjewels »

I believe so, genuine Mitsubishi part to suit VZ 6 litre
MPC001
Posts: 174
Joined: Sat May 05, 2018 11:41 am

Re: PWM Control of GM Alternators

Post by MPC001 »

:thumbup: same. Thank you
Knackersjewels wrote: Sat Dec 13, 2025 10:37 pm I believe so, genuine Mitsubishi part to suit VZ 6 litre
V8fan
Posts: 143
Joined: Sun Oct 31, 2021 8:27 pm
cars: Astro VAN

Re: PWM Control of GM Alternators

Post by V8fan »

Knackersjewels wrote: Sat Dec 13, 2025 10:49 am I have a pwm alternator on one of my LS vehicles, using P59. Couldn't get it natively controlling it properly, so bought a cheap pulse width controller. 128hz, 92% duty gets around 14.8v from the scanner, and on the gauge, if unplugged, it defaults to 13.5v
I use DR44 from escalade 2011 with 2 pins voltage reg originally
Without signal it produce 13.6 and as I read -its failsafe voltage
Because I havent wires in my wiring harness from PCM to alternator - I simply change voltage regulator to older model (-2007 4 pins) that can work without any signal and can light warning lamp directly into cluster
It will be interesting to make custom controller to control not only voltage but enable current protection (I have OEM current sensor that has output as frequency)
My plan is to use LTO battery but I wanna add overload protection to alt
User avatar
Tre-Cool
Posts: 533
Joined: Tue Oct 16, 2012 2:17 am
cars: VY SS UTE, VX Drag Car
Location: Perth

Re: PWM Control of GM Alternators

Post by Tre-Cool »

not sure if you find this helpful or not.

Just converted a vz 6lt crewman to a 2010 6l80e. Both following combo's require EVC generator options to be turned off otherwise voltage sits at 11.5v. (I just used the same parameters from the 2006 ecu into the newer units)
VF-Alternator-Charging.png
2011 VE ecu os 12659270 & tcm-24256125, then went to VF-OS - 12656930 & TCM-24267577

I can mix-match tcm os with the either ecu code.
You do not have the required permissions to view the files attached to this post.
MPC001
Posts: 174
Joined: Sat May 05, 2018 11:41 am

Re: PWM Control of GM Alternators

Post by MPC001 »

Tre-Cool wrote: Sun Jan 25, 2026 10:31 am not sure if you find this helpful or not.

Just converted a vz 6lt crewman to a 2010 6l80e. Both following combo's require EVC generator options to be turned off otherwise voltage sits at 11.5v. (I just used the same parameters from the 2006 ecu into the newer units)
VF-Alternator-Charging.png

2011 VE ecu os 12659270 & tcm-24256125, then went to VF-OS - 12656930 & TCM-24267577

I can mix-match tcm os with the either ecu code.
Thanks for the share Tre-Cool! Did the last two items need changing as well to disable RVC? G1006/7?

On the ECM TCM OS interworking, I must put some effort into getting C6 12628990 or 12635863 or 12639270 running properly with 24243170 when i get a chance.
Have had 12628990 running but shifts & idle a bit off. I have a gold blade TB to go in now, maybe that was why >> more playing. :comp:
MPC001
Posts: 174
Joined: Sat May 05, 2018 11:41 am

Re: PWM Control of GM Alternators

Post by MPC001 »

Very cool !
Tre-Cool wrote: Sun Jan 25, 2026 10:31 am
Just converted a vz 6lt crewman to a 2010 6l80e.