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GM - chimes without headunit - any analog output anywhere I can tap in

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I have no headunit, no need for a $50 harness but after having no chimes for the first time today I realized this means no blinker noise or low gas warning. I'd like to restore that, but it would be the ONLY output I'd need from the harness making me not want to buy one. Of course, if the signal is only over the CAN bus and has no analog counterpart it'll cost me something, but was curious if anyone has rednecked a good solution?

And yes, I'll still have a stereo in the Escalade (2010) but it'll be a carputer and no headunit.

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Yikes! If it where time vs money I think I would blow the 50 bucks. 

 

Heres a "how to" on extracting the data you are after and how to build your own "gateway" jumper. 

 

http://theksmith.com/software/hack-vehicle-bus-cheap-easy-part-1/

http://theksmith.com/software/hack-vehicle-bus-cheap-easy-part-2/

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Time is money, but I'm cheap lol.

Long term I want to do basically that anyways as I'd like to move up to a 14" screen but that will require removing the HVAC controls from the dash as well. tongue.png

Just don't want errors in the interim.

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Seems a relay with the appropriate resister in the circuit is needed between the BUS and the CAN to keep the system in logic mode. Otherwise go's dominant and calls for the reset you speak of.

 

CAN nodes listen to the bus, and will only attempt to transmit frames if the bus is idle. As soon as the bus becomes idle, however, multiple nodes may attempt transmission simultaneously.

Since dominant (0) wins out over recessive (1) on the CAN bus, an individual node can check to see if its recessive bits are indeed recessive. As long as they are, then it may continue transmitting.

If a node detects a dominant (0) bit when it has attempted to send a recessive (1) bit, it stops transmitting, and yields to the other node(s) until idle.

Note that that the frame identifier therefore is related to the priority of the frame. Frame identifiers will be chosen such that high priority devices will win arbitration over lower priority ones.

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If it was me I would find somebody that had already reverse engineered the interface module and can provide a schematic.

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It is not trivial but can be done. Would require a 5 lead relay to cycle a signal to the CAN, and appropriate resistor on the trigger wire for the correct frequency. The corresponding pins to connect to are posted online. I would start with 100 or 120 ohm resistor and observe its corresponding effects and adjust as necessary.

Or just quit being chintzy and spend the 50 bucks. I am sure an hour of your time is worth more than that. :)

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you know me, I'll probably do both Doh.gif

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Yikes! If it where time vs money I think I would blow the 50 bucks. 

 

Heres a "how to" on extracting the data you are after and how to build your own "gateway" jumper. 

 

http://theksmith.com/software/hack-vehicle-bus-cheap-easy-part-1/

http://theksmith.com/software/hack-vehicle-bus-cheap-easy-part-2/

this is gold. dude figured out exactly what I need to get steering wheel controls to interface with my n7. joycon to canbus fuckery didn't work for me 

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Seriously? I haven't actually tested mine, but EXPECT it to work.

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Seriously? I haven't actually tested mine, but EXPECT it to work.

my only thought was that i didn't get the correct pac adapter or im incompetent. 

 

new plan is this bluetooth scan tool and use the app he developed. 

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That scan tool sucks.

I've had two die. Work fine for checking but if you leave them plugged in all the time they last a few months.

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Maybe others have had better luck. First one just pooped, second one caused all sorts of shit to fly off on the CAN bus on my truck. All sorts of lights.

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Just want to see if this could be a solution. I'll spend money on a nice unit later if need be. 

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