TPMS Issues
Safety Car
Joined: May 2011
Posts: 3,807
Likes: 508
From: Oshawa, Ontario
I copied the quote below off another Thread and if it is right the PVC Pipe Work Around for Drag Radials will Not Work. Sensors in the PVC pipe will be in Sleep Mode when they get pinged by the computer therefore Reading XX.
The sensor has a radio transmitter in it that sends the pressure and that sensor's unique ID# to the TPMS computer in the car on a 315 MHz signal. (The sensors in 2010+ Vettes also send the temperature).
The TPMS computer (actually part of the RCDLR module) has a receiver that picks up the transmission from the sensor, and as explained in a previous post, the BCM and PCM process the data and send the pressure to the DIC.
The TPMS knows which pressure is coming from which corner of the car because it knows which sensor ID# is located on each corner.
As mentioned in earlier posts, when the car sits still for more than 15 minutes the sensors go into a battery saving mode and only transmit once very 60 minutes.
When you start driving over 20 mph the sensors wake up and transmit once every 60 seconds.
There are 2 pieces of sensor data that are stored in the TPMS memory:
The sensor ID#, so the TPMS knows which transmission correlates to which corner of the car (transmissions from sensors on other Vettes are disregarded because the TPMS only recognizes transmissions from the 4 sensor ID#s that are stored in its memory)
The last pressure transmitted by the sensors, so that when you start the car you'll have a pressure displayed until you back out the driveway and then drive down the street and get over 20 mph so the current pressure will be transmitted to the TPMS.
The sensor ID#s are in a non-volatile memory, and they will be remembered even when the battery is disconnected.
The last known pressures are in a volatile section of the TPMS memory, and when the battery is disconnected the last known pressures will be lost. When you start the car you'll have 0 psi displayed until you drive faster than 20 mph to wake up the sensors where they will transmit once every minute, so after a battery disconnect (or dead battery) you'll have to drive faster than 20 mph for a minute or two to get the current pressures transmitted to the TPMS and displayed in the DIC. The TPMS still has the sensor ID#s (it didn't lose those when the battery was disconnected) so no relearn procedure is required.
A TPMS tool transmits a 125 KHz signal. That signal triggers the sensor (forces it to send out its data), and when a "relearn" procedure (sensor info is programmed into the TPMS) is performed, the current pressures will immediately be displayed in the DIC - no need to drive the car to see the current tire pressures.
Bob
The sensor has a radio transmitter in it that sends the pressure and that sensor's unique ID# to the TPMS computer in the car on a 315 MHz signal. (The sensors in 2010+ Vettes also send the temperature).
The TPMS computer (actually part of the RCDLR module) has a receiver that picks up the transmission from the sensor, and as explained in a previous post, the BCM and PCM process the data and send the pressure to the DIC.
The TPMS knows which pressure is coming from which corner of the car because it knows which sensor ID# is located on each corner.
As mentioned in earlier posts, when the car sits still for more than 15 minutes the sensors go into a battery saving mode and only transmit once very 60 minutes.
When you start driving over 20 mph the sensors wake up and transmit once every 60 seconds.
There are 2 pieces of sensor data that are stored in the TPMS memory:
The sensor ID#, so the TPMS knows which transmission correlates to which corner of the car (transmissions from sensors on other Vettes are disregarded because the TPMS only recognizes transmissions from the 4 sensor ID#s that are stored in its memory)
The last pressure transmitted by the sensors, so that when you start the car you'll have a pressure displayed until you back out the driveway and then drive down the street and get over 20 mph so the current pressure will be transmitted to the TPMS.
The sensor ID#s are in a non-volatile memory, and they will be remembered even when the battery is disconnected.
The last known pressures are in a volatile section of the TPMS memory, and when the battery is disconnected the last known pressures will be lost. When you start the car you'll have 0 psi displayed until you drive faster than 20 mph to wake up the sensors where they will transmit once every minute, so after a battery disconnect (or dead battery) you'll have to drive faster than 20 mph for a minute or two to get the current pressures transmitted to the TPMS and displayed in the DIC. The TPMS still has the sensor ID#s (it didn't lose those when the battery was disconnected) so no relearn procedure is required.
A TPMS tool transmits a 125 KHz signal. That signal triggers the sensor (forces it to send out its data), and when a "relearn" procedure (sensor info is programmed into the TPMS) is performed, the current pressures will immediately be displayed in the DIC - no need to drive the car to see the current tire pressures.
Bob
Last edited by irok; Jan 28, 2018 at 12:24 PM.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,108
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
I have no other wheels bedidr the car with TPMS in them. I do have the 2 old sensors and 2 more new sensors in a cabinet next to the car. The new sensors are not Clones. They are AC Delco 20925924 which is the GM OEM replacement. O am moving the old and new unused sensors way away from the car. I will then re program the ones in the PVC and try again.
Could my rear tire diameter cause this? Mickey Thompson ET Street SS 305/35 R19 @ 27.8 Diameter.
Note: The spinning in the lathe didn't change anything.
Could my rear tire diameter cause this? Mickey Thompson ET Street SS 305/35 R19 @ 27.8 Diameter.
Note: The spinning in the lathe didn't change anything.
It seems the info dribbles in, in bits and pieces, and not necessarily specific or decipherable, as in "bedidr".
Lets start with "bedidr". So what word did you mean?
When you moved the sensors stored in the cabinet to another location, what is the distance in feet? BTW, wrapping them in aluminum foil would work better. The DIC has been reading info from your old sensors (in the garage) and when the RCDLR pinged the sensors 30 minutes later, the car was too far away, so it interpreted (correctly) that the sensors weren't there. It never pinged the new sensors, because you never activated them and the RCDLR doesn't know they exist. You can verify that by attempting to relearn the car while the old sensors are out of range.
When you spun the sensors in your lathe, did you orient them in the same plane as if they were mounted in a wheel? If so, what was the RPM attained and how far from the centerline was the main body mounted? That's really important in things like the centrifugally created delay in artillery shells that doesn't arm the projectile until it's attained enough speed/distance/rotation after being fired, so you don't blow yourself up.
With sensors you don't have that concern.The size of your tires doesn't affect the sensor readings.
Thread Starter
Race Director
Joined: Nov 2017
Posts: 12,759
Likes: 10,657
From: Prosper TX/Austin TX
2020 C6 of the Year Winner - Modified
Pro
Joined: Nov 2014
Posts: 577
Likes: 15
From: Tampa Florida
I relocated all the unused sensors in the back garage about 200 ft away. I don't think there is a chsnce it will read them that far away. I spun the sensors at 1000 rpm for 5 mimutes in the lathe about 10 ft from the car and far away from the old sensors. I took it for a drive and at the 30 minute mark the light came on Service Tire Monitor and both rear sensors read XX. Now it is raining so I am making a hold down bracket for my new Lithium Battery. I will most likely order the LG Track Box and say Screw these Sensors.
Last edited by 7SECONDS; Jan 28, 2018 at 07:41 PM.
Safety Car
Joined: May 2011
Posts: 3,807
Likes: 508
From: Oshawa, Ontario
I relocated all the unused sensors in the back garage about 200 ft away. I don't think there is a chsnce it will read them that far away. I spun the sensors at 1000 rpm for 5 mimutes in the lathe about 10 ft from the car and far away from the old sensors. I took it for a drive and at the 30 minute mark the light came on Service Tire Monitor and both rear sensors read XX. Now it is raining so I am making a hold down bracket for my new Lithium Battery. I will most likely order the LG Track Box and say Screw these Sensors.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,108
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
I relocated all the unused sensors in the back garage about 200 ft away. I don't think there is a chsnce it will read them that far away. I spun the sensors at 1000 rpm for 5 mimutes in the lathe about 10 ft from the car and far away from the old sensors. I took it for a drive and at the 30 minute mark the light came on Service Tire Monitor and both rear sensors read XX. Now it is raining so I am making a hold down bracket for my new Lithium Battery. I will most likely order the LG Track Box and say Screw these Sensors.
The switch in a tire pressure sensor is designed to be activated when spun at somewhere around 250 RPM (20 mph on a 26.7" tire) when mounted about 7" from centerline and oriented in the same position as it would be when correctly located on a wheel. If any one of those minimum requirements is not met, you won't attain the needed centrifugal force in the exact direction to trip the switch.
Until you turn that switch on the first time, the battery is not connected and you can't get a response from the RCDLR's request for the serial identification. Without an activated sensor's newly supplied ID to replace the previous one, the RCDLR will default to the original sensors's ID, no matter where the sensor is located. If the old sensor is too distant to reply to a request for pressure, the RCDLR will display the last known pressure until it times out at 30 minutes.
The solution is really simple. In this order: Take your old sensors that are already activated, keep them separated by a few feet while near the car and relearn them to the car (they probably already are, but do it anyway), verify by getting a 0 pressure or flat tire DIC warning, put them in the PVC container, pressurize it to something over 25 psi and less than 42. I'd try 33 psi, since it'd compensate for temperature changes without hitting the limit for a DIC warning.
Intermediate
Joined: Mar 2017
Posts: 31
Likes: 0
I should state that I have original wheels with replacement Hankook tires. Replaced tires at 11K. Non run flats for the ride. (about a year ago). Then got a flat in the rear last May. Replaced both rears for balance.
Didn't have phone chrging. Wife was doing something online but that really shouldn’t make a diff?
Didn't have phone chrging. Wife was doing something online but that really shouldn’t make a diff?
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