Circuit Functions
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The injection pressure regulator (IPR) is a pulse width modulated (PWM) variable position valve that regulates pressure in the injection control pressure (ICP) system. The IPR restricts the return flow path for oil from the high pressure pump. As the duty cycle increases, the IPR restriction to the drain increases, thus increasing the ICP. The IPR duty cycle is controlled by the powertrain control module (PCM) and is modulated from 0 to 65% dependent upon the desired injection control pressure.