Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Throttle Position Sensor: Description and Operation


The TPS, connected to the throttle shaft, is a variable resistor with one end connected to 5 volts from the ECM and the other to ground. A third wire, connected to the ECM, measures TPS voltage. TPS voltage changes with movement of the throttle valve. The ECM modifies fuel delivery according to throttle valve angle, by monitoring TPS voltage.