DTC P028: Transaxle Pressure Switch/Circuit Problem: Description

The PCM checks for illegal transaxle pressure switch inputs (000 and 010) in addition to any of the following three failure conditions:

1. Transaxle range switch indicating not in P/N but the transaxle pressure switch input to the PCM indicating P/N (101) with a valid drive transaxle gear ratio (3.11 or less).
2. Transaxle pressure switch input to the 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).
3. Transaxle pressure switch input to the PCM indicating D1 (110), D2 (111), D3 (011), or D4 (001) with a reverse gear ratio (gear ratio between 2.02 to 2.23).

If any of the above conditions are met for 5 seconds, Code P028 will set for the entire ignition cycle.