It appears the desired Commanded Duty Cycle PWM % is a tunable parameter on some PCMs while not on others. Does anyone know if there is a way to adjust the charge output voltage on the PCM OS'* where this commanded duty cycle % is not accessible & adjustable?

Commanded Duty Cycle Generator Output Voltage:

10% 11.00 V
20% 11.56 V
30% 12.12 V
40% 12.68 V
50% 13.25 V
60% 13.81 V
70% 14.37 V
80% 14.94 V
90% 15.50 V

I don't know of a way.

I'm curious: What would you have it do differently than it currently does?

No current need to change any of my LeSabre'*. I'm just accustom to being able to adjust the charge voltage. It'* a bit strange to me that with a PWM controlled field current, GM chose (at least initially) to not include making it adjustable. But to give credit where it'* due, adjustability was added to the newer PCM O.*.

I think HP Tuners will change it.
Found another source about installing a resistor inline with the wire.

Let me know what year your asking about and I can pull a config file down from the repo and see exactly what is tuneable alternator wise.

Thanks Mike, it'* a 2005 LeSabre, Serv NBR 12583827, P04 PCM. I've looked through the tabs in HPT & did not see it. Hopefully, I'm missing it

Are you looking for the HPT calibraton file?

I've read the PCM with HPT, so I have the calibration file but as far as I can tell, adjusting the voltage is not supported on the P04 PCMs. I have opened some calibration files for other (newer) PCMs and the voltage adjustment is available in the system tab.

I seen a reference somewhere find it in the airflow tab.

I need to dig out my old laptop that still has Windows 10 on it and fire HPT up. The rest of my machines are Linux because I refuse to upgrade/buy new machines for Windows 11.

I appreciate your help, Mike.

You would need to program the PCM.