Theory Of Operation

WARNING: This page is about a different variant/trim than selected.

The transmission gear disengagement mode means that the spool is moved to a position that allows fluid pressure coming from the pressure control solenoids (electrovalves) PPV1 and PPV2 to move the actuator to disengage the target gear and move it to its intermediate neutral position. This diagnostic checks for the proper operation of the electrovalve PPV1 which engages 2nd, 3rd or Reverse gear and of the electrovalve PPV2 which engages 1st, 4th, 5th or 6th gear. The diagnostic performs seven different tests during the gear disengagement mode to ensure that the electrovalves are capable to disengage the target gear and stop the actuator in the intermediate neutral position. This is accomplished by verifying that the opposite gear of the target on the same actuator is disengaged. If one of these tests fail the diagnostic will be considered failing.