12P control of RVC alternator

[bf6379]

I am thinking about running an alternator off a VF Commodore on a car with an 808. These alternators are externally regulated, using a PWM signal from the PCM.
I am hoping that I can use one of the Flex Outputs on the 808 to control the alternator.
I am currently away for work for an extended period, in COVID isolation (i.e. need mental stimulation) and can't install Tunerpro on my work laptop.
Can someone tell me (or take a screenshot) what input axis parameters are available in the Flex Output Editor? Also, what Pin Frequency range is available?
Thanks.

[antus]

Here are the options for the flex outputs.

12p flex outputs.png (150.73 KiB) Viewed 2760 times

The PWM from the FAQ here viewtopic.php?f=7&t=1396

Q. What type of PWM is the $12P flex outputs?
A. Its electrically a low side (ground side) driver.
It is a static 32hz, with 0-100% duty cycle programmable against anything in the ecus data stream.
It is suitable to drive solenoids and electronic engines
It is not suitable for most PWM signalling applications (eg PWM IAC)
Safe current draw from the ecm is around 500ma.

[bf6379]

Here are the options for the flex outputs.

12p flex outputs.png

The PWM from the FAQ here viewtopic.php?f=7&t=1396

Q. What type of PWM is the $12P flex outputs?
A. Its electrically a low side (ground side) driver.
It is a static 32hz, with 0-100% duty cycle programmable against anything in the ecus data stream.
It is suitable to drive solenoids and electronic engines
It is not suitable for most PWM signalling applications (eg PWM IAC)
Safe current draw from the ecm is around 500ma.

So it looks like I can't use a flex output to control the alternator directly. I need 128 Hz.

The VF alternator doesn't have a direct output for driving an alternator light, so I can still use a flex output for that.

The "Universal A/D", is that the input voltage at pin B12?

Apart from the frequency, why is it "not suitable for most PWM signalling applications"?

Thanks,

[antus]

I am 95% sure it is B12, but I cant find a way to validate that without testing at the moment. B12 is a 0-5v input.

The reason it is not suitable for most PWM applications is the frequency. Most hardware that says its PWM doesnt clearly describe its frequency, but 32hz is not common, so that text is there as a bit of a red flag to stop people buying hardware thinking it will work because its PWM without looking closely at the details.

[bf6379]

I am 95% sure it is B12, but I cant find a way to validate that without testing at the moment. B12 is a 0-5v input.

The reason it is not suitable for most PWM applications is the frequency. Most hardware that says its PWM doesnt clearly describe its frequency, but 32hz is not common, so that text is there as a bit of a red flag to stop people buying hardware thinking it will work because its PWM without looking closely at the details.

From the ECM circuit diagram, B12 does look like a 0-5V input. But the OSE12P pinout diagram says it is 0-25V.

Pin B2 has a 5.12 to 1 voltage divider on the input, so maybe that is the 0-25V input and not B12.

12Pwiring.pdf

(75.75 KiB) Downloaded 149 times

[antus]

Hmm that is an old document, and that is an error. The (non-public) changelog of 12P v110 says "Renamed spare 0-5v Analog input B12 (Not 25.5v as previously documented) [Tested ok]"
Is that still present elsewhere on the site? I will need to update it.

I dont really understand what the change was here. I never heard anybody talk of ecm damage, and I recall the scaling issues on the 25v pin, so it sounded functional. B2 is a 25v 'cranking' input. I am not sure what its function is, and if you can use it as a general purpose input instead. I suspect you can, and maybe it is only carrying a B+ start signal for the purposes of the logs now.

[delcowizzid]

B2 cranking input was for backfire inhibit logic on a crank to no crank failed start

[bf6379]

Hmm that is an old document, and that is an error. The (non-public) changelog of 12P v110 says "Renamed spare 0-5v Analog input B12 (Not 25.5v as previously documented) [Tested ok]"
Is that still present elsewhere on the site? I will need to update it.

I dont really understand what the change was here. I never heard anybody talk of ecm damage, and I recall the scaling issues on the 25v pin, so it sounded functional. B2 is a 25v 'cranking' input. I am not sure what its function is, and if you can use it as a general purpose input instead. I suspect you can, and maybe it is only carrying a B+ start signal for the purposes of the logs now.

Yes, it is still on this site at download/file.php?id=5105 and download/file.php?id=2949

B2 was used on VN and VP V6's, at least. It received 12V when the starter motor was cranking.

Unfortunately, it appears that none of the spare analog inputs (C7, C8, C9, C15 or D11) were added for use in the 12P Flex Output Editor. It looks like we have B12 to use, and maybe D8 called "Wideband AFR".

[antus]

Thanks for the links. Yes if your not tuning with wideband you can use that input. or you could disable cranking backfire inhibit logic and use that input.

I have updated both wiring diagrams and also updated the links to them across the whole site except for this thread (so there is a reference in context of what we are talking about)

[bf6379]

Thanks for the links. Yes if your not tuning with wideband you can use that input. or you could disable cranking backfire inhibit logic and use that input.

How can I use an input that isn't on the "Axis Variable" list of the Flex Output Editor?