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Discussion Starter #1
Hey guys... I just finished changing out my front turn signals and was wondering what this plug behind the hood release switch was for. Is it power for the HIDs leveler? Block heater? Remote alarm/engine starter? Neons for the engine area? Hmm... That's not a bad idea!
:crazy:

Any ideas??




More info and photos on the SilverStar turn signals:
http://mazda3forums.com/viewtopic.php?p=36719#36719

EDIT: Title - I'm sure you mean "what" not "what the..." :twisted:
 

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Discussion Starter #3
Suppose. I don't use a diagnostics machine. But I thought it was a different connection anyway, like a 9 or 15 pin connector.
 

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DJ Spencer said:
Suppose. I don't use a diagnostics machine. But I thought it was a different connection anyway, like a 9 or 15 pin connector.
ya i dunno, just tossing that out there... the OBDII connnector is under the dash on most (all?) cars made nowadays...
 

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BMM3 said:
My guess, the block heater. The diag. connector is by the hood release under the dash.
That sounds about right. It looks like it has two slots, one for power and one for ground. Diagnostics would need a minimum of three slots, power, ground, and serial communication.
 

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Discussion Starter #7
So what you are saying is that I can run neon in my engine area?? :)

j/k.. HONEST!
 

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Well, serial lines are usually in threes because you need a send, receive, and ground. There is no "power" line. You need send and receive in order to complete software handshaking, which you almost certainly need in any type of a diagnostic hook-up.
 

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LeeLee said:
Well, serial lines are usually in threes because you need a send, receive, and ground. There is no "power" line. You need send and receive in order to complete software handshaking, which you almost certainly need in any type of a diagnostic hook-up.
LeeLee, I worked with this stuff a my last job. You know those seat sensors that sense the passenger to determine if the passenger airbag should deploy or not? I tested the prototypes of those before they were mass manufactured. Serial communication does not need a return because the one wire is a send and receive. CAN is probably the protocol that is used in a Mazda for communication and CAN is single-wire communication. The power line is usually not to supply power, but as a reference voltage for the communication line, same thing with the ground. These references are needed because the tester's computer is almost never hooked up to the car by any other means but the dignostic hook up so they need to know what the high and low references are for the communication.
 

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Discussion Starter #10
that is true, but only if the one cable is TSR. We use them in the music industy all the time. You would also use a similar cable on the back of a TiVo unit. It basically looks like a stereo headphone jack (TSR - Tip, Sleave - Ring).

So in essence, you are both correct. TSR is generally used to send a mono signal out to a processor, return the mono signal to the board, and have a ground in between.
 

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DJ Spencer said:
that is true, but only if the one cable is TSR. We use them in the music industy all the time. You would also use a similar cable on the back of a TiVo unit. It basically looks like a stereo headphone jack (TSR - Tip, Sleave - Ring).

So in essence, you are both correct. TSR is generally used to send a mono signal out to a processor, return the mono signal to the board, and have a ground in between.
No, it is not one cable, serial communication on automobiles is one wire. I did look under the passenger seat to see if Delphi, the company I worked for, was responsible for the passenger seat detection system and they weren't. It was kind of surprising because Delphi did do the detection systems for Ford, Jaguar, and Volvo.

But, to go back to my arguement, automobile serial communication can and is almost all done through one wire. If it is through two wires it is not because of a send and receive wire, it is because the communication can operate at two speeds depending on what each of the ECUs are talking to (Safety systems, drivetrain, entertainment, etc.). This is the way VW, GM, Ford, Volvo, Jaguar, Saab, Subaru, Nissan and many other manufacturers do it.

GM is implementing a LAN type of communication with three different speeds and the stereo is required for the warning chimes. If you don't have the stock stereo in the vehicle then the chimes will not work. My friend had to do this with his GMC Sierra.
 

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I know what that plug is for.....








Its to plug something in it... Duh.
 

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Discussion Starter #13
vaBooM said:
Its to plug something in it... Duh.
Smartass. I could have figured that out! :bigsmile:
 

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Discussion Starter #15
yeah, I kinda thought about the temp gauge, either mirror or radio display.

I'm tempted to stop by my dealer today and ask for the manual so I can figure it out.

Has anyone tested it to see if it's live or not?
 

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I know exactly what it is.....
















Its a plug. And something plugs into it. And its live! So dont touch it. It may come to life and eat you.
 

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Discussion Starter #17
"Feed me Seymor!"
 

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Lmao... omg I havent seen that movie in ages. There is a porno (not that I watch em or anything...) called Little Shop of Whores.

I seen it in Vegas, while browsing the PPV list.
 

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Discussion Starter #19
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