Code P028, Transaxle Pressure Switch/Circuit Problem: Notes
WARNING: This page is about a different car, the 1995 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
PCM checks for illegal transaxle pressure switch inputs (000 & 010) in addition of any of following failure conditions:
- Transaxle range switch indicating no in P/N position but transaxle pressure switch input to PCM indicating P/N (101) with a valid drive transaxle gear ratio (3.11 or less).
- Transaxle pressure switch input to PCM indicating REV (100) with a gear ratio not within recognized reverse gear ratio range (gear ratio less than or equal to 2.02 or gear ratio greater than or equal to 2.23).
- Transaxle pressure switch input to PCM indicating D1 (110), D2 (111), D3 (011) or D4 (001) with a reverse gear ratio (gear ratio between 2.02 and 2.23).
If any of above conditions are met for 5 seconds, Code P028 will set for the entire ignition cycle.