Tire Pressure Sensor all scan except RR???
So if anyone has any inside on how to fix this problem that would be greatly appreciated!!!
First of all, you say they are unable to "trigger" or "excite" the RR sensor. Is that the one they replaced?
I'm not completely familiar with the XLR sensors, and of course the C6 didn't get produced until 2005, but I think your '04 XLR should have the same sensors as the C6.
A handful of very early C6 Vettes had a sensor that could be triggered by a magnet (GM Part# 10354988, which was a square black sensor). That sensor is no longer available and has been superceded by the current sensor (GM Part# 25758220, which is a "peanut" shaped gray sensor). The current sensor must be triggered by a radio frequency transmitted by a TPMS/sensor reset tool.
Did you see the sensor they broke? Do you know the GM Part# of the old one and the one they used to replace it?
Here are pictures of the 2 different sensors:
Below is the old sensor that is no longer available. This was in a handful of very early C6's, and may very well be the original sensors in your XLR. These sensors could be triggered by a magnet, but they are no longer available, and the replacement sensor needs a sensor reset tool to trigger it. You may be able to just make out the Part# 10354988 molded into the case.

You can't get that sensor above any more and it's been replaced by the sensor below, which MUST be triggered by the radio transmission from a sensor reset tool:
Below is a link to a video of my real early '05 C6 that has the 10354988 sensors in it. I am not able to trigger the ones in the front with a TPMS tool, they only respond to a magnet. However, the ones in the rear will trigger with either a tool or a magnet. The video shows me using a magnet on the front sensors and a tool on the rears. That may be what you need to do if they replaced your old sensors with a 25758220 sensor in the RR.
http://youtube.com/watch?v=uplJ8AaNKjw
So, if the RR is the sensor they broke and replaced, they replaced it with a sensor that must be triggered with a 125 kHz transmission from a tire sensor reset tool. If the original ones are the 10354988 sensors they may or may not respond to the tool, but they will definitely trigger with a magnet.
Good luck, and let us know how it works out.
Bob
On the C6, you have to program LF, RF, RR, and then LR in order.
So you might end up using the magnet for LF, RF, then going to the electronic scan tool for the RR, then back to the magnet for the LR.
This way, all the sensors will display correctly in your DIC.
Last edited by scottycards; May 5, 2008 at 05:20 PM.
On the C6, you have to program RF, LF, RR, and then LR in order.
So you might end up using the magnet for RF, LF, then going to the electronic scan tool for the RR, then back to the magnet for the LR.
This way, all the sensors will display correctly in your DIC.
As I mentioned in a post above, I have the old style sensors in my early '05 C6. In that video in one of the posts above, I use a magnet on the front 2 sensors and tool for the 2 rear sensors.
You'll know if a sensor is triggered because if it is you get a honk of the horn - no horn honk, it didn't work. If you try a magnet and don't get a honk, try the tool. If you're using the tool and don't get a honk, try a magnet.
Bob
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One thing is bothering me thou now that they are all programmed the RR is showing pressure of 30 PSI constantly while the others are showing 35 PSI??? I checked the RR and its reading 35 PSI with the tire pressure gauge??? Any updates on this one???
Now....what's up with the 30 psi reading in the RR???
I assume you were using a tool at your GM dealership (Cadillac or Chebie). If so, you should have been working with a Kent-Moore J-46079. Here's a video where I'm doing some diagnostic checks on some sensors. Notice that I push the "Activate" button when working with the sensors:
You did push the "Activate" button when using the tool, didn't you?
If you push the "Simulate" button it does an entirely different thing. It doesn't trigger the sensor, rather it sends a bogus sensor ID# and also a bogus tire pressure to the TPMS, but you will still get a honk of the horn because the bogus sensor was registered properly. This is to test the TPMS computer, and it will not trigger the sensor in the wheel to get it to send its data to the TPMS computer.
If you did use the "Activate" button, then you did it correctly.
Have you driven the car since doing the relearn?
When the car is parked for more than 15 minutes the sensors go into a "sleep" mode and only transmit once per hour. When you start driving the sensor "wake up" when you go faster than 20 mph and start transmitting to the TPMS every 60 seconds (sooner if they detect a change in pressure).
So....usually after you adjust the pressure using your gauge, you'll have to drive faster than 20 mph for several minutes for the DIC to start getting the correct transmissions from the sensors and display the proper pressures.
Good luck with it, but at least you're on the right track!!!
Bob
Last edited by BEZ06; May 7, 2008 at 10:15 PM. Reason: added video link
If I put the car into Learn Mode and use the magnet on the other 3 wheels it works no problem but as soon as I get to the RR (the one I have been having problems with) and press activate like your post to do the XLR won't honk what so ever?? So when I get out of Learn Mode in the car it displays the Service Tire Monitor message again.
Now this is where it gets tricky...I put the car into Learn Mode again and this time I use the magnet but when I get to the RR (the one with the new sensor) I use the J46079 and go into simulate mode and simulate the sensor and for some strange reason I get a Honk from the XLR??
I do not understand why it's only reacting to the Simulate Mode and the Activate Mode? Please if someone could resolve this mystery to me that would be super...The only thing I have left to do is use another tire pressure sensor tool.
If I put the car into Learn Mode and use the magnet on the other 3 wheels it works no problem but as soon as I get to the RR (the one I have been having problems with) and press activate like your post to do the XLR won't honk what so ever?? So when I get out of Learn Mode in the car it displays the Service Tire Monitor message again.
Now this is where it gets tricky...I put the car into Learn Mode again and this time I use the magnet but when I get to the RR (the one with the new sensor) I use the J46079 and go into simulate mode and simulate the sensor and for some strange reason I get a Honk from the XLR??
I do not understand why it's only reacting to the Simulate Mode and the Activate Mode? Please if someone could resolve this mystery to me that would be super...The only thing I have left to do is use another tire pressure sensor tool.
You need to trigger or excite the sensor, which forces it to transmit its data. 3 of your sensors are triggered by a magnet, and the new one is triggered by a 125 kHz radio frequency transmission from the TPM tool.
Take a look at the video below where I'm using a tool that looks almost exactly like the J-46079 tool you've been using. Make sure you pay attention to where I put the antenna - I put the end of the antenna on the rubber sidewall of the tire right next to the valve stem. This puts it as close as possible to the sensor - which is just inside the tire on the end of the valve stem.
DO NOT PUSH THE SIMULATE BUTTON!!!! The "Simulate" button is to test the TPMS computer in the car. It gets the tool itself to transmit a phony sensor ID# to the TPMS computer in the car, along with a phony tire pressure - this is to test the TPMS without needing to have sensors that are working properly. When the "Simulate" mode transmits this bogus sensor ID#, the TPMS receives the data and gives a honk of the horn. It doesn't know if the data is from a phony transmission made up by the tool, or if it's from a real sensor that was triggered by the tool - all it knows is that it is in the learn mode and received a proper radio signal containing a sensor ID# that it can log into its memory, and when it does that it gives a honk of the horn.
What you should do is put the car in the learn mode, use the magnet to trigger the LF and RF sensors (getting a honk of the horn at each tire), then use the tool on your RR sensor by pushing the "Activate" button (which will send the radio frequency to trigger the sensor, and you will get a honk of the horn if the sensor triggered properly), then use the magnet on your Left Rear where you will get a "double honk" indicating all 4 sensor ID#'s are properly logged into the TPMS memory. Turn off the ignition and you're done.
You can practice with the tool by just going back to the Right Rear sensor, putting the end of the tool on the tire sidewall, and pushing the "Activate" button. You don't need to be in the learn mode or anything - you can just walk up to the car with the doors closed and locked. You can walk up to any GM vehicle with sensors in a parking lot and check its sensors with the J-46079 tool.
When you know where to position the antenna to effectively trigger the sensor, then you can put the car in the learn mode and do the full relearn procedure with the magnet for LF, RF, the tool for the RR, and the magnet for the LR.
BTW, you can also check the magnetically triggered sensors with this tool. Without putting the car in the learn mode, just walk up to any sensor that you want to do a diagnostic check on. Push the "Scan" button and then put your magnet over the valve stem of the magnetically triggered sensor. When the magnet triggers the sensor to send out its data, the tool will intercept the transmission and will display the sensor ID# and the tire pressure. The little triangle in the upper left of the screen will give you an indication of the internal battery strength of that sensor's battery - if the triangle fill in completely solid the signal strength was strong indicating a strong battery.
Good luck, and give us a follow-up on how it works.
Bob
Glad it's fixed now

BTW, do you know what part# the car needed? I think it should be the same as for the C6, GM Part# 25758220.
Bob










