Step 2: 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.