Signals on the TPM wires
08-18-2016, 06:27 PM
#1
Signals on the TPM wires
Hi everyone,
Saw the recent Cultrag post for the TPMs kit. I have the '01 and newer TPM sensors and the correct later model fobs. There are three wires going to the antenna box, Orange 12 v Black Grd and pink that is the data bus. My goal is to see if I need an antenna box.
I verified the orange and black wires having good ground and a solid 12 volts. I was wondering if anyone knew what to look for on the pink wire. With a Picco scope connected, should I see a square wave or analog signal? Or, will it not exhibit anything with the car running? I know that's a deep pair of questions but I'm hoping someone has a good working system and has tried to see what is being sent on that pink wire. I have a No Com display on the DIC for the TPM, so, I verified the two wires I knew what to expect with. Now its down to the pink wire.....
Thanks
Yellow '01
Saw the recent Cultrag post for the TPMs kit. I have the '01 and newer TPM sensors and the correct later model fobs. There are three wires going to the antenna box, Orange 12 v Black Grd and pink that is the data bus. My goal is to see if I need an antenna box.
I verified the orange and black wires having good ground and a solid 12 volts. I was wondering if anyone knew what to look for on the pink wire. With a Picco scope connected, should I see a square wave or analog signal? Or, will it not exhibit anything with the car running? I know that's a deep pair of questions but I'm hoping someone has a good working system and has tried to see what is being sent on that pink wire. I have a No Com display on the DIC for the TPM, so, I verified the two wires I knew what to expect with. Now its down to the pink wire.....
Thanks
Yellow '01
08-19-2016, 05:45 AM
#2
Team Owner
Hi everyone,
Saw the recent Cultrag post for the TPMs kit. I have the '01 and newer TPM sensors and the correct later model fobs. There are three wires going to the antenna box, Orange 12 v Black Grd and pink that is the data bus. My goal is to see if I need an antenna box.
I verified the orange and black wires having good ground and a solid 12 volts. I was wondering if anyone knew what to look for on the pink wire. With a Picco scope connected, should I see a square wave or analog signal? Or, will it not exhibit anything with the car running? I know that's a deep pair of questions but I'm hoping someone has a good working system and has tried to see what is being sent on that pink wire. I have a No Com display on the DIC for the TPM, so, I verified the two wires I knew what to expect with. Now its down to the pink wire.....
Thanks
Yellow '01
Saw the recent Cultrag post for the TPMs kit. I have the '01 and newer TPM sensors and the correct later model fobs. There are three wires going to the antenna box, Orange 12 v Black Grd and pink that is the data bus. My goal is to see if I need an antenna box.
I verified the orange and black wires having good ground and a solid 12 volts. I was wondering if anyone knew what to look for on the pink wire. With a Picco scope connected, should I see a square wave or analog signal? Or, will it not exhibit anything with the car running? I know that's a deep pair of questions but I'm hoping someone has a good working system and has tried to see what is being sent on that pink wire. I have a No Com display on the DIC for the TPM, so, I verified the two wires I knew what to expect with. Now its down to the pink wire.....
Thanks
Yellow '01
That same receiver is also used by the key FOBs for lock/unlock, etc. Have you tried unlocking a door/trunk, etc while watching the scope?
HTH
08-19-2016, 12:28 PM
#3
Tech Contributor
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
You can MAKE THE OEM GM SENSORS transmit by putting a MAGNET on the sensor. The reed switch or motion sensor inside the TPS connects when the tire rotates above a set speed OR when the magnet actuates it.
It must be a digital signal to be able to send exact changes in pressure. That's my guess..
Inquiring minds need to know.
It must be a digital signal to be able to send exact changes in pressure. That's my guess..
Inquiring minds need to know.
08-20-2016, 08:37 PM
#4
Signal
Thanks for the quick reply. I have not tried the scope on this wire yet. I was unsure if the module was in constant communication with the DIC and BCM. I now have the correct fobs #1 and #2 for the 01 through 04 cars. I will be putting the 01 through 04 module in and will go through the fob learning process and see what is taking place on the wire. At this point, if I get the fobs to work it will be a good start. Then I'll start with the wheel sensors and go through that learning process. I will update this post as I move forward and, of course, as funds roll in and time permits
Love the Hillary avatar......Yellow '01
Last edited by Yellow '01; 08-20-2016 at 08:39 PM.
08-22-2016, 12:53 PM
#5
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It's definately part of the serial bus communications so it will resemble a square wave of data. The problem watching it in car is that you will also see all the communications signals from all the other modules so you'll have no idea if the data you're seeing is being sent by the receiver or not. You could try powering the module up without the data wire connected and monitor it to see if you get a signal when you put a magnet near a TPM or press a button on the remote.
08-22-2016, 10:02 PM
#6
It's definately part of the serial bus communications so it will resemble a square wave of data. The problem watching it in car is that you will also see all the communications signals from all the other modules so you'll have no idea if the data you're seeing is being sent by the receiver or not. You could try powering the module up without the data wire connected and monitor it to see if you get a signal when you put a magnet near a TPM or press a button on the remote.
Good point! there will be a blaze of stuff going on on that wire. One thing that will tell me is that that wire is connected and has continuity. I'll try hooking the picco up on the pink wire disconnected from the bus and see if it at least responds and creates its own signal.
Yellow '01