Case NumberK92303407 Vehicle IssueTransmission will not upshift from third into fourth gear.;The transmission Neutrals out when trying to up shift to fourth or shifts back to third after attempting to shift to fourth. Codes P0730 Incorrect Gear Ratio or P1731 Incorrect Gear Engaged may set.System or ComponentSlips,Transmission Jumps out of Gear;Customer Concern (No DTCs),DTC / Error Message;Malfunction Indicator Light / MIL / Check Engine Light,Automatic Transmission / Transaxle;3-4 Upshift;Moderate Speed / 25 - 50 MPH ( 40 - 80 KPH ),Higher Speed / Greater than 50 MPH ( 80 KPH );AccelerationRecommendationThere is a known issue with a 3-4 shift flare or neutraling out on the 3-4 shift. In most cases this event is accompanied by a P0730 Incorrect Gear Ratio code or P1731 Incorrect Gear Engaged code. The cause of this event is ferrous or Aluminum debris in the 3-4 Shift Pressure and/or 3-4 Holding valves. Rather than replacing the valvebody, split the valvebody, remove the steel separator plate from the upper VB, and remove the steel endplate covering all the 3-4 shift valves, remove the valves and flush out the bores and valves with a solvent such as mineral spirits. Re-assemble the VB and re-install to roadtest. Only if the valves are still sticky after the flush or if the 3-4 shift issue persists, should the VB be replaced.
Modification Date10/20/06 9:50 AM