Hello & Welcome,
Has the dealer done anything else, that you know of, besides replace the sensors for the tires? Is there anything on the paperwork about any Programming or Learning the sensors?
I think I understand, and from the symptoms you described (one of the psi readings being blank), it does sound like one sensor.
Let me send along a description of the system and the schematic. That way you will have more information to work with these folks.
I am assuming that you are dealing with a GM dealership that has the capability to read the specific error codes that come back from the system, and that has pointed them to a particular sensor. As you might be able to tell from the schematic, these sensors are just pressure sensors that transmit a signal to the receiver. If one of them is blank (like you saw), then that would point to that particular sensor.
So far they have changed 3 out of four, which only leaves one to go. If this was a GM dealership, it would surprise me that they did not get it right the first time, and that they would not have looked for something else wrong the second time (or the third). If this is NOT a GM dealership, and they don't have the right tools to properly diagnose the problem (scanner that will tell them what sensor has bad signal), then perhaps they were just "guessing" and have one shot left.
I believe there is also a calibration / relearn procedure that should be done whenever the tires are changed or rotated so that the system knows which tire to display as the problem. That is why I was asking about the paperwork details. Most shops will list the relearn procedure as a line item on the paperwork as a final step before testing.
I hope this helps and gives you more information to go on. Please let me know what happens or if I can provide more information.
Take Care, Greg A.
You didn't mention that it was different tires each time, or I missed that point.
Is this a GM dealership?
I'm sorry - I missed that point in the original question.
The BCM is located on the lower left side of the Instrument Panel (IP) below the steering column. It is not shown directly in the schematic as it is part of the path between the passenger door module and the instrument panel cluster.
Your graphic did not make it, but you can try again if you want. You should be able to use the "little tree" icon on the toolbar to upload it if you would like. If you can't see the toolbar, click on Show Toolbar.
Yes, I had seen that bulletin. That is why I was asking if you were going to a GM dealership, which should have been aware of this.
If this is a GM dealership, they should be aware of the bulletin and be using ALL the same (modern) sensors. They should also be doing the relearn procedure for all the wheels when the sensors are replaced. Here is that procedure, as a PDF file.
I do not know the particular frequency that is used.
You are quite welcome,
If they said they would fix it, stick with their promise and make them fix it.