cylinder pressure measurement on toyotas?

[SRavet at bangate.compaq.com]

I found this paragraph in a TI application note on engine knock detection 
using the 320 series of DSP processors:

Pressure sensors measure the pressure inside the combustion chamber of a 
running engine. This direct measurement of the combustion process provides 
the best signal to analyze to detect engine knock. However, each cylinder 
requires its own sensor, and individual sensor costs are still relatively 
high. As a result, pressure sensors are used primarily in research 
settings. Currently, Toyota is the only manufacturer that installs pressure 
sensors in production engines. Pressure sensor usage will increase in the 
future as sensor costs are reduced and automotive companies develop more 
sophisticated engine control strategies that monitor the combustion 
process.

Does anyone know any more about these pressure sensors that Toyota installs 
on production engines?

--steve

Steve Ravet
sravet at bangate.compaq.com
Baby you're a genius when it comes to cooking up some chili sauce...