PCM should apply 3rd gear clutch by opening ground circuit of 3rd line actuator. PCM also controls hydraulic pressure to 3rd gear clutch housing. If PCM detects 3rd gear clutch slipping, PCM will increase line pressure. If clutch is still slipping, PCM will set code 23.

NOTE: Test numbers refer to numbers on diagnostic chart.

If present, go to information flag listed. Using flow charts, check for possible causes of trouble code.
See ACTUATOR QUICK CHECK under SELF-DIAGNOSTICS. Ensure clicking sound from 3rd line actuator is similar to clicking sound of other line actuators.
See HYDRAULIC PRESSURE TESTS in AUTO TRANS OVERHAUL - SATURN article. If line pressure does not change or only changes a little, regulator valve is stuck.
Remove valve body. Apply air pressure to 3rd apply port. See HYDRAULIC PRESSURE TESTS in AUTO TRANS OVERHAUL - SATURN article.
Cross-channel leaks may cause other clutches to be applied. If PCM detects other gears are stuck on, other codes will be present. This may help locate cross-channel leak.
This step checks for 3rd clutch operation. If clutch applies and releases, check valve body for damage. If clutch does not operate okay, check for failed clutch plates.

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.

Safety Warning

Code 23 - No 3RD Gear: Description

Use the Manual With the Right Hardware

When to See a Mechanic

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