Step 2: Fake Out Computer

Picture of Fake Out Computer
I decided that I wanted to test the repair. Also, I had put a regular tire stem on the wheel with the broken TPM. This wheel could be used as the spare tire where I'm less concerned about monitoring the pressure. Therefore, I was in no hurry to re-mount the TPM. However, I wanted the dashboard light to go out and only report if one of the other 4 tires on the wheels had low pressure.

I needed a way to put the repaired TPM under more than 26 psi air pressure.

I took a short section of 4" ABS pipe and glued a cap on one end and a threaded plug on the other. These parts cost me $15. Any similar closed container that you have on hand would work just fine.

I drilled a 0.4"" hole in the ABS cap and fitted the TPM. After pressuring the pipe to 30 PSI the dash board idiot light went out!! I can carry the tube next to the tire jack.

I'm a little worried that this looks like a pipe bomb if I'm ever stopped by the police. I'm thinking of putting a label on the pipe saying "Tire Pressure Monitor Tester". That should cover it.

All this could be avoided if Toyota made the engine computer open to owners without special electronics.

A simpler way to fool the Tire pressure monitor computer, use "Gorilla" tape to adhere the broken sensor to the drop center of the spare wheel. this also works well for all the tires if needed. most small repair shops will not charge much to break down the tire for that purpose, Usually less than the money spent on the pipe pieces. I have used this often without an issue... *note: other brands of duct style tape come loose over time, "Gorilla" brand works best for longevity.*

P.S.- Vehicle have Tire Pressure Monitor Computers separate from the Engine management computer. However they do communicate through the CAN bus lines as well as transmission, SRS, ABS, and various other computers in most vehicles. Some parts stores and most small repair shops also have the basic TPMS reset/learning tool on hand and do not charge as much as a dealer to relearn new sensors to the vehicle.

turbonut482 years ago
Can you remove all the sensors and mount them on the canister? The you can use sensorless valve stems.
randy82k5 years ago
Great invention! looks like you can remount it in the tyre now. I think you could also use large PVC pipe. might save money as the large size ABS gets expensive.