proper way to test data wires
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=125028
Printed Date: April 29, 2024 at 11:07 AM
Topic: proper way to test data wires
Posted By: chev104275
Subject: proper way to test data wires
Date Posted: December 13, 2010 at 6:17 PM
As the title states. What is the best/proper way to test data wires ? CanH and CanL
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If i Can't Install it I Don't need it Joe
Replies:
Posted By: cjanke
Date Posted: December 13, 2010 at 6:47 PM
IDK . Maybe an o-scope. I guess we just have to trust the bypass manufacturers in the instruction manuals.
Posted By: chev104275
Date Posted: December 13, 2010 at 6:57 PM
That's what I've been doing. Trusting the pinout charts. But my work is starting to get me more data modules so I would just like to know how to test the wires so I know they are the right ones. Data modules are sooooo much eaiser. I've been doing everything wired
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If i Can't Install it I Don't need it Joe
Posted By: KPierson
Date Posted: December 13, 2010 at 8:21 PM
The only surefire way is with an oscilloscope.
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Kevin Pierson
Posted By: chev104275
Date Posted: December 13, 2010 at 8:31 PM
Ok. Thanks I'll just have to trust the pinout sheets that comes with the modules. It's been good so far. Just hate connecting wires without verifying first
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If i Can't Install it I Don't need it Joe
Posted By: ayalja123
Date Posted: December 13, 2010 at 8:35 PM
Yes, they are some much easier. I remember doing passlock systems and having to find the right resistor value. Now you just find that data wire and you got tach,doors, trunk.....etc. New guys don't know how easy we have it now. But back to your subject I would also like to find out how to test for them.
Posted By: howie ll
Date Posted: December 14, 2010 at 12:34 AM
You CAN (I had to didn't I) test with a good quality high impedance DMM (Fluke etc.), but you need to know the values, I'd stick with a scope myself.
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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: chev104275
Date Posted: December 14, 2010 at 5:30 AM
Ok I have a dmm not sure if its high impedence or not its made by BK test bench model 388A and access to a scope. What am I looking for with each one ?
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If i Can't Install it I Don't need it Joe
Posted By: KPierson
Date Posted: December 14, 2010 at 10:15 AM
With your scope you should see square wave type data. You, obviously, won't be able to understand what the data is saying, but you should see data on the line.
It should be just random patterns of highs and lows.
__--___--__--------____---___-----_____--------------______----______ ------------- Kevin Pierson
Posted By: awdeclipse
Date Posted: December 14, 2010 at 11:04 AM
How about tracing them back to the OBDII connector? Do a continuity check between where you are grabbing the data wires and where they are already known. A quick Google image search will turn up some pictures for you if necessary.
PIN6 - CAN High
PIN14 - CAN Low
Posted By: chev104275
Date Posted: December 14, 2010 at 3:53 PM
Thanks guys. Should be able to figure it out from here.
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If i Can't Install it I Don't need it Joe
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