TPMS issue, could use some advice*
09-09-2017, 04:49 PM
#1
Race Director
Thread Starter
TPMS issue, could use some advice*
Need some help please, the TPMS system on my 04 C5 is going bonkers. The LF just shows xxx. While the RR says it's flat, but has 32psi. Yesterday the LR was flat though. It has been fixed and that sensor reads fine. I have no codes.
A friends uncle works at the local Chevy dealer in this small town I'm. So I took it down there and they couldn't get the scan tool to read it to try and cal the TPMS. No Vette specific mechs there at the dealership.
They want to tear it apart and look for what ever. Any suggestions or should I let the dealer have at it?
Thanks for any help.
A friends uncle works at the local Chevy dealer in this small town I'm. So I took it down there and they couldn't get the scan tool to read it to try and cal the TPMS. No Vette specific mechs there at the dealership.
They want to tear it apart and look for what ever. Any suggestions or should I let the dealer have at it?
Thanks for any help.
09-09-2017, 08:22 PM
#2
Race Director
Thread Starter
Are you 100% certain that there are NO CODES??? Did you pull the codes through the DIC using the procedure in the following video?? Did the B0 - RFA have NO COMMS next to it????
https://www.youtube.com/watch?v=SviRjIsy9G4
https://www.youtube.com/watch?v=SviRjIsy9G4
09-09-2017, 08:32 PM
#3
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The batteries in the monitors have about a 10 year life expectancy. If yours are original it may be time to replace them.
09-09-2017, 11:09 PM
#4
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Thread Starter
The service manager was saying something about had I been having issues with the remotes for the car. I know according to the factory service manual that the RKE system activates the tire monitors? Unless I read it wrong. But I told him I've never had an issue with the remotes.
09-10-2017, 08:59 AM
#5
Team Owner
Just replaced mine this year with the new tires. However, on my 2008 Malibu one sensor is dead and another is acting up. Will swap them when new tires go on in December. They are the originals. The ones that are still reporting in will at times give me the wrong pressure from what I know is in the tire by gauge.
09-10-2017, 09:26 AM
#6
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
The OEM Tire Pressure Sensors are trained/acutated using a MAGNET. The magnet closes a small reed switch inside the sensor and makes it report or transmit its signal to the RFA. The BCM learns where that sensor is and that is how the BCM knows what tire position its transmitting.
If your mechanics are trying to program the sensor with a scan tool, they are doing it incorrectly!!! They MUST put a MAGNET over the TPMS Sensor inside the rim of the tire.
NOTE! Some aftermarket TPMS use different procedures to make it learn the position. Some you have to let the air out of the tire and then refill the tire to learn the sensor position.
Bill
If your mechanics are trying to program the sensor with a scan tool, they are doing it incorrectly!!! They MUST put a MAGNET over the TPMS Sensor inside the rim of the tire.
NOTE! Some aftermarket TPMS use different procedures to make it learn the position. Some you have to let the air out of the tire and then refill the tire to learn the sensor position.
Bill
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Grim Reaper (09-10-2017)
09-10-2017, 09:27 AM
#7
Race Director
Thread Starter
You did indeed misunderstand.... 
The TPMS and the Key Fobs are BOTH transmitters (neither are receivers) and do not interact. The Remote Function Adapter (RFA) is the receiver for BOTH these transmitters. Each transmitter sends an encoded transmission that the RFA receives, decodes and then sends the information contained to the BCM, PCM or IPC as needed over the Serial Data Buss system that interconnects ALL the sensors in the car.
Had the B0 - RFA reported NO COMM then BOTH the FOBS and TPMS would not work since their path is via the RFA and then the Serial Data Buss to the other computers that act on or report on the information each transmits.
The TPMS and the Key Fobs are BOTH transmitters (neither are receivers) and do not interact. The Remote Function Adapter (RFA) is the receiver for BOTH these transmitters. Each transmitter sends an encoded transmission that the RFA receives, decodes and then sends the information contained to the BCM, PCM or IPC as needed over the Serial Data Buss system that interconnects ALL the sensors in the car.
Had the B0 - RFA reported NO COMM then BOTH the FOBS and TPMS would not work since their path is via the RFA and then the Serial Data Buss to the other computers that act on or report on the information each transmits.
I'm no expert on this system so maybe the book isn't exact. Sounds like I may need to replace the sensors or at least a couple of them. 14 year old car should just change them all. I do know the dealer tech was having an issue getting the system to read and the service manager started talking PCM issues and key fob problems. That's when I started thinking I needed some help from people with Corvette knowledge as he admitted they had no tech that was Corvette specific or an expert.
Appreciate you guys opinions and help.
Last edited by Grim Reaper; 09-10-2017 at 09:33 AM.
09-10-2017, 10:34 AM
#8
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If you can use the FOBs to LOCK/UNLOCK the car and or open the trunk and or trip the panic button, The RFA is WORKING PROPERLY.
If the FOBs do not work, You may need to RE-SYNC or RELEARN the FOBs.
Here is a schematic of the complete system:
Bill
If the FOBs do not work, You may need to RE-SYNC or RELEARN the FOBs.
Here is a schematic of the complete system:
Bill
09-10-2017, 12:34 PM
#9
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Thread Starter
RCDLR is Remote Control Door Lock Receiver which is another term that the GM shop manual uses for the Remote Function Adapter or RFA.
What ever term you want to use it is a Radio Frequency (RF) receiver and doesn't "control" anything. It is simply the middle man in receiving transmissions, decoding the transmission and passing the decoded information on to the BCM, PCM and IPC who need the information that was transmitted. Yes it is integral to being able to get the requests/information from the key FOB and TPMS to those other sensors that use it. The RCDLR/RFA does NOT communicate back to either the FOB or the TPMS because it is a receiver and not a transmitter and the FOB and TPMS are transmitters and not receivers.
If by "control" you mean that it allows the display of information in the DIC, then yes it does allow/facilitate that function by passing the received information along so that it can be displayed.
RCDLR/RFA is simply a receiver-converter. Receives radio transmissions and converts them to serial data to be put on the serial data buss.
What ever term you want to use it is a Radio Frequency (RF) receiver and doesn't "control" anything. It is simply the middle man in receiving transmissions, decoding the transmission and passing the decoded information on to the BCM, PCM and IPC who need the information that was transmitted. Yes it is integral to being able to get the requests/information from the key FOB and TPMS to those other sensors that use it. The RCDLR/RFA does NOT communicate back to either the FOB or the TPMS because it is a receiver and not a transmitter and the FOB and TPMS are transmitters and not receivers.
If by "control" you mean that it allows the display of information in the DIC, then yes it does allow/facilitate that function by passing the received information along so that it can be displayed.
RCDLR/RFA is simply a receiver-converter. Receives radio transmissions and converts them to serial data to be put on the serial data buss.
Got it, like I said I'm no electrical person. Bill, the schematic you show is the same one in the factory manual I have. The FOBs also work properly, lock, unlock, open the hatch and panic mode.
8VETTE7, I believe your previous comment could be the most logical (batteries not working). This car hasn't ever been worked on by a dealer since I've owned it. Original owner had a few warranty items done. I've always been able to do the work myself until this TPM stuff popped up. Maybe replacing all the sensors, as I believe they are original, would be the logical option at this point.
Appreciate both your opinions and help with this. If you feel changing the sensors is not called for, then I probably need to let the dealer here take a look at it.
09-10-2017, 12:48 PM
#10
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Just order 4 new GM OEM TPMS on line (MUCH LESS EXPENSIVE Than the stealership) and have any tire store break the bead and install new sensors.
I stay away from dealerships as they charge MUCH more than outside repair shops.
I stay away from dealerships as they charge MUCH more than outside repair shops.
09-10-2017, 01:21 PM
#11
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Don't you love how the stealership's inability to diagnose a simple issue usually leads to spending money on computers and big ticket items that are functioning properly.
Replace all 4 and be done with it. I have also been able to change them by deflating the tires breaking the bead so you don't have to dismount the tires causing you to re-balance.
Replace all 4 and be done with it. I have also been able to change them by deflating the tires breaking the bead so you don't have to dismount the tires causing you to re-balance.
09-10-2017, 02:28 PM
#12
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Thanks guys, I'll try the relearn option first. If that don't work. I'll order 4 new sensors. Thanks again
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capevettes (09-10-2017)
09-10-2017, 07:29 PM
#13
Racer
There was a thread a while ago about replacing the batteries. Well, that didn't turn out well...
I have tried 2 different vendors for TPMS with no luck. Each type responded to the learning with the magnet, but then never reported the tire pressure. I just gave up. I just press reset each time the check message comes up.
I read that this cannot be turned off on MY 2000, but can be disabled on later years - C6?
I have tried 2 different vendors for TPMS with no luck. Each type responded to the learning with the magnet, but then never reported the tire pressure. I just gave up. I just press reset each time the check message comes up.
I read that this cannot be turned off on MY 2000, but can be disabled on later years - C6?
09-10-2017, 07:36 PM
#14
Melting Slicks
The OEM Tire Pressure Sensors are trained/acutated using a MAGNET. The magnet closes a small reed switch inside the sensor and makes it report or transmit its signal to the RFA. The BCM learns where that sensor is and that is how the BCM knows what tire position its transmitting.
If your mechanics are trying to program the sensor with a scan tool, they are doing it incorrectly!!! They MUST put a MAGNET over the TPMS Sensor inside the rim of the tire.
NOTE! Some aftermarket TPMS use different procedures to make it learn the position. Some you have to let the air out of the tire and then refill the tire to learn the sensor position.
Bill
If your mechanics are trying to program the sensor with a scan tool, they are doing it incorrectly!!! They MUST put a MAGNET over the TPMS Sensor inside the rim of the tire.
NOTE! Some aftermarket TPMS use different procedures to make it learn the position. Some you have to let the air out of the tire and then refill the tire to learn the sensor position.
Bill
09-10-2017, 07:41 PM
#15
Melting Slicks
There was a thread a while ago about replacing the batteries. Well, that didn't turn out well...
I have tried 2 different vendors for TPMS with no luck. Each type responded to the learning with the magnet, but then never reported the tire pressure. I just gave up. I just press reset each time the check message comes up.
I read that this cannot be turned off on MY 2000, but can be disabled on later years - C6?
I have tried 2 different vendors for TPMS with no luck. Each type responded to the learning with the magnet, but then never reported the tire pressure. I just gave up. I just press reset each time the check message comes up.
I read that this cannot be turned off on MY 2000, but can be disabled on later years - C6?
09-12-2017, 05:02 PM
#16
Race Director
Thread Starter
I agree with Bill C that if your FOB's are working then there is nothing wrong with the RCDLR/RFA. And since the FOB's work there is no reason to do the "re-sync.
You can try to program the TPMS to the computer yourself with the following procedure:
https://www.youtube.com/watch?v=vOM96f3Iy6E
If you cannot get one or more TPM's to program then the MOST LIKELY cause would be the batteries in them are dead or nearly so. Typical life span for a TPMS is 8 to 10 years. Some quit sooner and some quit later but that range is typical. Assuming yours are original they owe you nothing at this point in their life.............
You can try to program the TPMS to the computer yourself with the following procedure:
https://www.youtube.com/watch?v=vOM96f3Iy6E
If you cannot get one or more TPM's to program then the MOST LIKELY cause would be the batteries in them are dead or nearly so. Typical life span for a TPMS is 8 to 10 years. Some quit sooner and some quit later but that range is typical. Assuming yours are original they owe you nothing at this point in their life.............
Thanks again for all the assist.
09-12-2017, 07:16 PM
#17
Race Director
Thread Starter
[QUOTE=8VETTE7;1595557313]Once you get the new TPMS you can program them to the car BEFORE you have them installed if they are the OEM ones that train with a magnet. Just be certain to mark them as you train them and then install each in the correct position on the car as seen on the video above.[/
I ordered the AC Delco ones using the GM part # verified by Gene Culley. Paid less then half of what the dealer quoted me for a price.
Good info on doing it before. That way I know if I already have a bad one.
I ordered the AC Delco ones using the GM part # verified by Gene Culley. Paid less then half of what the dealer quoted me for a price.
Good info on doing it before. That way I know if I already have a bad one.
Last edited by Grim Reaper; 09-12-2017 at 07:17 PM.