Getting power to radio and MMCS--what was the trick?

It seems that someone posted they bypassed the ACC setting to keep the radio and MMCS systems on during START. The key switch opens the ACC circuit during 'cranking', so the MMCS starts booting up when you first turn the key to ACC, then it is rudely interrupted for the START, then starts booting up again at ON.

i just want to separate that function to reduce stress and wear and tear on the electronics.

edit: here's a link to the schematics key switch schema

I don't know the answer to this, but I'll just note that I pass through ACC as quickly as possible -- i.e. I go to START in one motion. I know the manual says to leave it in ACC for two or three seconds. I never do that. As a result, I've never noticed this issue.

I've mentioned before that I see no purpose to ACC mode on this car. It seems like all it does is provide you with a faster way to run down the 12V battery. Does anyone else feel differently?

wmcbrine said:

I don't know the answer to this, but I'll just note that I pass through ACC as quickly as possible -- i.e. I go to START in one motion. I know the manual says to leave it in ACC for two or three seconds. I never do that. As a result, I've never noticed this issue.

I've mentioned before that I see no purpose to ACC mode on this car. It seems like all it does is provide you with a faster way to run down the 12V battery. Does anyone else feel differently?

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I also do one swift key turn to start it.

As for the ACC.... you must not have a teenager that can't be left in the car without "tunes" on while you run into a store .... :lol:

I've mentioned before that I see no purpose to ACC mode on this car. It seems like all it does is provide you with a faster way to run down the 12V battery. Does anyone else feel differently?

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It's most likely a holdover from ICE cars. The reason you wait a couple of seconds before cranking an engine is to allow the fuel pump to build up pressure. We don't have that issue.

Ever since I first got the i-MiEV, I've went straight to start and released, and it's been going to READY without issue so far. If it doesn't go to READY, I know I either still have the car plugged in (twice happened to me) or I didn't hold Start long enough. I do the same with my parents' C-Max. It's amazing how fast that car goes READY (nearly instantly).

PV1 said:

...It's amazing how fast that car goes READY (nearly instantly).

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I think it was jray3 who first pointed this out as another i-MiEV advantage. We jump into the car, turn the key, snap on the shoulder harness, and GO - without any time-costly initialization delays. oops, off topic

tigger19687 said:

As for the ACC.... you must not have a teenager that can't be left in the car without "tunes" on while you run into a store .... :lol:

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I don't, but this is what I'm saying -- why not just stay in Ready mode for that? In an ICE or hybrid car, you might change to ACC so that you didn't run the engine and burn gasoline. But in this car, all it does is draw from the 12V instead of the main battery. And that seems undesirable, considering that you have a nice gauge to show your main battery charge, while the only indicators you get with the 12V are a warning light you never want to see, or catastrophic failure. Plus, the 12V just doesn't run very long.

PV1 said:

It's most likely a holdover from ICE cars.

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Exactly. I feel like the ACC mode should've been designed right out of the i-MiEV... or I'm missing something.

wmcbrine said:

-- why not just stay in Ready mode for that? ...

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I think that you perhaps meant to say ON switch setting without "starting" the car into READY. I just took a few CaniOn readings (351vdc): in ON it's 0.7A and 0.2kW; in READY it's 1.3A and 0.5kW. Isn't the big distinction between ACC and ON simply that the HV pack is not activated during ACC? The dashboard displays are not energized in ACC and the Bluetooth OBDII is also not energized in the ACC switch setting so can't check the HV pack power draw but I suspect it's zero. Sitting in the car running the radio for a long time while not charging will surely deplete the 12v battery, so it would perhaps be a good idea to kick it into ON for a few minutes every once in a while to replenish the 12v battery.

We leave it in the 'ON' position all the time when someone (usually the wife) runs into a store . . . . many times for half an hour or more - The A/C doesn't function if you switch it to ACC :lol:

Don

Good points. I will do that from now on.
I guess I was worried more about the car moving due to gear or something going wrong. But I always put the hand brake on when I put it in Park.

Back to the original topic question -

kiev said:

...i just want to separate that function to reduce stress and wear and tear on the electronics....

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kiev, thanks for posting the schematic. I share your pain as it also bothers me to have things unnecessarily turn on then off then back on (such as energizing the car simply to shut a window). To answer your question, I don't recall anyone posting a bypassing scheme which would still have to ensure power to the MMCS being off when the key is turned to OFF.