Fault Code 28: Pressure Regulator (Line Short Circuit To Ground, Or Open Circuit)/Pressure Regulating Solenoid (MV4) Open Circuit
NOTE:
For circuit reference, see WIRING DIAGRAMS .
This fault code will cause the transmission to switch to limp home mode in low and high ranges. It will also cause a shift in pressure to maximum and harsh gear shifts/engagement.
For fault code description and diagnostic test procedure, see Fig 1 and Fig 2 . Freeze frame variables are N-MOT, VGT-$X and UBATT. See TEST PROCEDURE under SELF-DIAGNOSTIC SYSTEM.