The pressure sensor is linked to the engine computer. Its main function is to signal to the computer that there is additiobnal load on the engine when power steering is turned during idle so that the computer would increase the idling speed if necessary.
If the idling speed drops too low, it means the idling speed is not being compensated by the load produced by the pump working under pressure.
If the idling speed is not stable, it could be due to the idle control system and celaning the throttle body and IAC would help.
Friday, October 12th, 2012 AT 12:53 PM