The check system light has been on for a lil while,showing a low tire( I just thought it was a bad TPMS sensor)...I know all the tires have like 35 psi in them..so had a friend scan the car..and it was showing a pressure reading in all 4 tires...and had some codes as well...C2121...C2122...C2123...so we erased them to see if they would come back...and they didnt...at least for a day or so..now the light is back on..anyone had any problems like this before? how can it show all 4 tires TPMS are working ..and then the light is on?

 

Did you check the pressure in the spare?

 

Did you check the tire pressure while each was COLD? What was the the psi for each? What year is your 350?

Spare doesn't have a tpms in it...

 

yep...was alil low..but filled it up..initalized it...still the same???, but good catch..thanks!...oh yeah that was a cold test on the psi and its an 07..and set the front cold to 36psi and the rear to cold 38psi..

 

After filling the tires with air, drive the vehicle, the TPMS warning should go away after a few minutes of driving.

 

the check system display is still on...and still get a reading from all TPMS?...anyway to reset...like pulling a fuse to the ecm/pcm or something???

 

Any chance you accidentally switched the car to look for the second (nonexistent in this case) TPMS set?

 

no..they are on the main set...any way to reset the TPMS computer...or whatever controls them?

 

The codes that you mention are trouble codes. There is no signal from your tpms. Here are the possibilities.

1. Tire pressure warning valve and transmitter

2. Tire pressure warning antenna

3. Tire pressure warning select switch

4. Tire pressure warning ECU and receiver

5. Wire harness or connector

 

i like to put the tires at the pressure that i want the warning to come on(about 30psi), initialize it, and THEN fill it to the pressure you want (I like 34-36). This way if your pressure goes down because of the temperature outside it won't be enough to trip ur tpms.

 

when it through those codes what was used to diagnose this?

 

is that you haven't program your new set of TPMS to your car's computer yet?

 

we have tried programming them at two different shops with two identical machines... problem is the ecu is not allowing the sensors to be programmed to the car... the sensors on my aftermarket wheels are straight from Sewell and I've had them on those wheels since september and never had this issue until after getting my car back from the dealership monday...

 

You pretty much HAVE to go back to the dealership to program it. Toyota dealership can do the same. Just my 0.02