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 16 - No 1ST Gear: Description
Manual shift valve controls hydraulic pressure to 1st gear clutch housing. First gear clutch is engaged in all forward gears. If PCM detects 1st gear clutch slipping, PCM will increase line pressure. If clutch is still slipping, PCM will set code 16.
- If present, go to information flag 14. Using flow chart, check for possible causes of low line pressure.
- See HYDRAULIC PRESSURE TESTS in AUTO TRANS OVERHAUL - SATURN article.
- Remove valve body. Apply air pressure to 1st apply port. See HYDRAULIC PRESSURE TESTS in AUTO TRANS OVERHAUL - SATURN article.
- This step checks for hydraulic or mechanical problems. See OVERHAUL article.
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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.