New tires. Sensors same location. Reading check sensors when done. Got XXX on all wheels.
Tried magnet reset. Front left reads and horn. Will not recognize other 3. Go to a friend. He tries with his electronic unit. Somehow it read and accepted. Wrong location but all read.

Two days later got sensors all four wheels XXX

OK 04 C5 so figure batteries are bad. Bought new sensors. Tried to progaram before I installed them on wheel. Still will not read any of the sensors.
Any suggestions ??????????????????????

 

I agree with 8VETTE7. If you got a horn sound from all 4 sensors (using the new ones), then they're fine. You wont' get readings from them till you either install them in the wheels and drive the car, or, alternatively, you could try shaking the devil out of one and see if it will give you a reading. If it does, of course you'll get an error for tire pressure low. I am not sure that will work, but it might. Maybe tie a string to it (real well and tape it) and then swing it in a circle to simulate a tire movement. Might get it to turn on and send a pressure (0) to the car.

 

Sirs,

You are both correct I did not make clear.
1. I know I will not get a pressure reading until mounted.
2. Since the original sensors with a powerful magnet will not sound horn in their program sequence and no signal at all I chose to try and program the new ones before mounting on wheels.
3. Went throug the proper sequence in programing. Started learnLF held sensor in my hand and put magnet. 15 to 20 seconds and no horn (what I meant in blue) in your response. Tried the programing 3 times. even tried different sensors all 4.
In addition I read that if the FOB are not programed it could make a difference. So I programed the FOB remotes 1&2. Then I again tried to learn the sensors without any luck. All I can think of is the sensors sent to me have been sitting for a long time and batteries are shot also or something else.
What is more frustrating is the old ones were working fine until I changed tires and polished wheel. Took senors off myself carefully before sending out.

 

A couple thoughts... It is virtually impossible for all TPMS to fail within a short amount of time. My '01 and '02 TPMS are still going strong with 70k+ miles on each set.

Are there any codes appearing on the DIC? Can you clear them all out, or are any persistent? Please make sure your doors & trunk are closed when training. Remove any battery charger if you have one attached. These all cause unwanted "chatter" on the OBD bus (I was sniffing), which inhibited my tire training last year.

The car battery is fully charged, and no other electrical issues present? Did you try disconnecting the battery then clear all codes?

Programming them in your hand at a short distance from the car should be fool-proof, assuming you have the right C5 TPMS. The magnet should be placed over the plastic body of the TPMS, not the stem. Please post the P/N of the new sensors you have.

The key fobs trained up OK, and work from a distance? If not, I may suspect a failing RFA or possible RF interference. Any other OBD devices attached like a window valet or logging tools?

Todd

 

Todd. The only thing I did not try was disconnecting - reconnecting battery. When I had old sensors off I wrote numbers down for future. Ones I got are identical including manufactoror. FOB trained without any problems. No codes come up except service TPMS system which I cleared before going to learn TPMS. I even went through the shop manual I bought (GM) manual. BY the book so to say. That is why I am so frustrated. Going to try the battery disconnect - reconnect and yes it is fully charged.
Thanks for the input all help has been appreciated.

Tony

 

Please keep us informed as to your progress and ultimate solution. In the spring I will need to purchase a new set of tires and since my car is a 2003, I will be changing all TPMS due to their age. I need to learn from your experience, but hope I don't experience the same frustrating situation.

 

From what I'm reading now, I'm going to go with "You've got the wrong sensors". I bet you've got the same issue this other guy had on the forum recently, he got a set of sensors for a late C5, only to find out they were really for an early C5. It's been in the last several weeks. You might do a search for another tpms thread. Also might be in general instead of tech. The thread had pics also. I'd do the search but I'm off to bed... now.

 

Thanks but I also thought of that. Like said before all 4 (old and new)cannot be bad at the same time. Checked vin # and the GM part number. Number and frequincy identical to both the old ones and new ones. Over next couple of days (bad snow yesterday) I am going to disconnect reconnect battery and see if that does anything. I will keep posted as to what happens. Thank you all for the input

 

Tony,

The frequency on almost all non-export GM key fobs and TPMS (not just C5) from that era are the same. It's the payload of the RF packet that varies. The right P/N should be 25773946.

Please describe your magnet and how strong it is. If it's attached to a fridge, it should be difficult to remove without a tool. To verify it's adequate, both Autozone and Oreilly's have a "key fob tester" at their counter. You should see their tester light go on within 3-5 seconds of applying your magnet to the TPMS. If not, it's too weak. It detects any RF broadcast on the TPMS/keyfob frequency.

To rule out RF interference, you might repeat the training in a parking lot.

If you have a buddy with an '01 to '04 C5, you could verify the new TPMS in your hand by temporarily training them to his car. Retrain his tires when you're done.

Doors, hood, and trunk closed to keep the OBD2 bus quiet. Keep us posted. Good luck, and happy new year.

Todd

 

What I took from your first post was that you could program them (old ones) if you went to your friends house and used his programming tool. No? That telling me the sensors were ok. Could the batteries be weak? Well, I suppose, but they're lithium batteries so they are pretty much a full power right till they are dead. Dying is a short process.

I don't think the key fob has anything to do with it. I'd be more inclined to think someone had some strange circumstances that made them think that was an issue. Then claimed it to be related. Sometimes, it just takes a few tries to get the things to program. I had that with new ones, and I could speculate but I really don't know why. You also might be getting XXX due to one not programming, and so the whole lot isn't being saved since the process didn't complete. I never tried doing only a few and seeing if it saved the ones that did chirp the horn. I don't think it does.

Does your fob unlock the car and pop the trunk like it should? If so, I'd say the receiver is working.

happiedazs, just make sure you test the new ones before you get them installed in the wheels. That way you know they work beforehand.

 

happiedazs, just make sure you test the new ones before you get them installed in the wheels. That way you know they work beforehand.[/QUOTE]

How do you test these things except by installing them and trying to fire them up???

 

How do you test these things except by installing them and trying to fire them up???[/QUOTE]

You can hold them in your hand and program them before you install them. Mark the first one as lf, then rf, then rr, then lr and install them in the correct location. You won't get a pressure reading until you install them and drive, but you'll know they program properly.

 

Number on new ones 25773946.
Disconnected battery and charged full just to make sure.
reconnected battery
Went to options on DIC and hit fuel 4 times. Read no codes on diagnostic.
Ran engine.
Went to learn sensors.
FL comes up first. Powerful enough magnet to pull a house down (almost)
after three tries (new sensors in hand) horn on first one. DIC says do FR. Tride three times for FR and nothing. Horn will not sound and will not recognize. Tried different sensors in different order. NOTHING
I checked the service manual and went through that.
What angers me is all was ok until I took the old ones out to do wheels and tires. Babied them gently. so I cannot have "eight" bad sensors.
I guess my next stop is a dealer.
Will update when I find something.

 

The front-Left programmed, just like before. I suspect it's process, not likely any failed components (maybe still one bad TPMS, but not 8) since one does actually train.

Involving a dealer at this point is only going to cost you some money, but they have the Tech-II to see exactly what's being received by the car's computers. Actually your tire installer may do this for free, and it will probably go without issue.

The RFA will not accept the same sensor in 2 different places (the serial number of the specific RFA is included in the RF transmission) so it just waits for the next unique broadcast to arrive. You have 8 available, and they can be scanned in any order while troubleshooting this issue (in case you do have a bad one in the bunch). For final training, you do want RF, LF, etc in the right positions.

Engine OFF, key ON? Or engine ON when attempting to train? I usually do it with engine OFF. Engine ON produces lots of OBD communication.

Just to confirm, you are applying the magnet to the black housing of one TPMS at a time for a minimum of 5 seconds until the horn sounds, correct? The other 3 TPMS are kept a few feet away until their turn.

I would suggest setting the 4 unmounted TPMS on the ground by the car for 10 minutes to settle out. Then turn Ignition on, engine off. Options/Fuel 4x, Train TPMS. At RF prompt, get out, close door. Pick up first TPMS and apply magnet. Wait for horn, put it down, pick up 2nd. Apply magnet, wait for horn. This confirms the training process. Work on the mounted ones once we get past this.

I'm still curious about this as well. The RFA also handles the key fob signals. Is it 100% reliable locking and unlocking the doors? No other oddities or intermittent U1xxxx codes?

If you have a friend nearby with an 01-04 C5 (non-Z06), you could try swapping RFA's with him and repeat the test. It's the other major component involved in TPMS, about $80 to replace.

This is a bit surprising, because training TPMS is usually a walk in the park. It should not be this difficult.

Todd

 

UPDATE

Went to my friends shop. He is a fantastic electrical guy.
1. Ignition on NOT engine. Cleared and went through till learn mode FL. He put his electronic unit on. Three times and walla horn. Now FR tried several times. NOTHING. Took another sensor. Again nothing. FOB is perfect and learnes right away. No issues.

WE now disconnect the battery and discharge ( touch both plus and minus leads together for five minutes. WE re-connect leads to battery and now with again the new sensors start again. Three tries and FL horn. Three more tries and FR horn. Four different times and RR horn and finally LR five tries and horn twice.
Removed old from rim and installed new in order they activated.

Hooray. Thanked him and told him will let him know if ok. I take it on the road. Nothing at first. Then highway and hit gauges.

Display is FL & FR show 28 psi RL shows nothing and RR shows 28

Tells me to come back. WE go through it agin ( now they are mounted on the rims) tries with his snap on tool. Nothing absolutly nothing. He feels that the new sensors that were sold to me have been sitting for a while and strongly feels the batteries are not good. My next step is to buy new ones somehwere reputable instead of fleabay and see what happens.

 

And how did you do this without blowing up your battery??????

Just curious how old your battery is. A weak battery can play havoc on the electronics in a C5...

 

I'm sure he means he touched the cars battery cables together to discharge the car, not while touching the battery itself. Not that it was needed, since disconnecting the battery for a few seconds does the same thing. There's no caps in the system for power ripple. Certainly none that would power the cars electronics for any measurable time. Be that as it may, it didn't hurt anything.

To the Op, I'm out of ideas for ya. Other than to say I think all the hardware on the car is working. I seriously doubt there's a battery problem with the sensors themselves. The new ones you got should have a date code molded in or stamped on. Mine did. Not that you can see that now if they're installed in the wheels. The lithium batteries have a very long shelf life. Typically with no load, 15 years.

I purchased mine off Ebay also. I've had zero issues. Just fyi.

As was mentioned above, this process is usually a slam dunk.

 

I'd make sure you can send them back, maybe find a place that will allow you to program before you buy. That way you are certain it's not good money after bad. Jmho.

 

Ahhh gotcha For some reason I was picturing shorting out the battery.... Moral of the story: champagne and corvetteforum don't mix.

 

For those who have been following this thread this is what happened. I receievd four brand new date 2012 AC Delco sensors. Tried to program before installing. NOTHING. So aT THIS POINT i GUESS THAT THE RECIEVER HAS TO BE BAD EVEN THOUGH THE fob IS WORKING.
Since I was going to buy a new reciever anyway I took out the old one. Took it apart sprayed with contact cleaner and blew off with air and let dry. Re-installed it. Took me two minutes to program the sensors. Contacts looked clean and I cannot explain it but everything is working. Mounted the senors on wheel and after a few mile all read identical pressure of 30 PSI. It was the reciever all along and I probably did not need new sensors to begin with but they were 8 years old so what the heck. will be shipping back the ones I bought on e-nbay their date code was 09 anway and one was definitly not working. Live and learn.

Thanks for all the input.