Suspected Bad 12V causing brake system codes?

In my experience it seemed like a low 12 volt generally gets you these communication problems on the gateway the can bus that sort of thing Don't really understand all that stuff don't really care but it seems like when you're 12 volt is out of spec these communication issues creep up red triangles get set things like that because things can't talk to each other there's not enough juice in the 12 volt system to keep everything alive or within spec computers apparently don't like that sort of thing and well they code they have a heart attack a mild stroke if you will but what's your showing 12.08 what have you. Is not really bad voltage You need over 12 and you need the necessary amperage behind the 12 volts The amperage is your muscle if you will If there's none of that there's not a lot happening You can have 12 volts in your battery and when you turn the car on the 12 volts turns to near nothing and there's no amps behind any of it and the battery flat lines and the car does nothing or it can be anywhere in between That's why a battery test like the old style where they short the terminals with the device and then there's a scale on it that gives you the energy you really have behind the 12 volts that you're seeing somewhat so you're right that's the first thing you want to be fooling with before you get to the expensive stuff is making certain that you have a 12 volt that is up to the pretty light tasks that it has to deal with so definitely make certain of that

 

The 41 has a good description on our blink codes page, which mentions the code is based on voltage measured at the brake electronics, so it could be the battery or it could be any of the wiring on the path bringing the power to the brakes. As the blink code page says, "it wouldn't be crazy to start by checking the 12 volt battery"; however, what you end up finding when you do that can be that it wasn't the problem.

A scan tool that can show you freeze-frame data from when the code was set can be very helpful. It will show what various voltages actually were at the instant the C1241 was set. A 12.08-volt reading by itself is nowhere near explaining a C1241 code: it takes 8.9 volts or less to set the code. But what you want to see is what the supply voltage may have been pulled down to at the instant the code was set. You can also see, in the freeze frame, whether the car was READY at the time or not (so you know if the power at that time was coming from the DC/DC converter or the battery). The freeze frame also includes "INF codes" that give you more information. One possible cause for a C1241 involves the capacitor box at the back of the car, next to the 12-volt battery.

Some of the other codes in your list I am not finding in the old 2006-edition repair manual where I am looking right now. Sometimes it is worth counting the blinks again to make sure of what the codes are.

Without more information than that, it probably makes sense to try to resolve the C1241 first, and then see what other codes come back, if any.

 

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