Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code P028, Transaxle Pressure Switch/Circuit Problem: Notes
1992 Saturn SL1 AutomaticSECTION Notes
WARNING: This page is about a different car, the 1995 Cadillac Seville. 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.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.