Buy Acura RSX Automatic Transmission Solenoids

The transmission solenoid is an electronic valve that opens and closes tiny fluid passages inside the RSX's 5-speed automatic gearbox. It changes oil flow so clutches engage smoothly.
On the RSX, the shift solenoid set (often called "solenoid A" and "B" or "linear pressure solenoids") mounts on the top-front of the case, under a small aluminum cover next to the battery tray. A short wire harness plugs it into the transmission control unit (TCU). (ClubRSX, Wikipedia)

Inside every automatic gearbox, hydraulic oil does the heavy lifting. The TCU sends a low-voltage signal to the solenoid coil; that magnetic pulse moves a pint-size steel plunger, uncovering an orifice so pressurized fluid reaches the right clutch pack. (Wikipedia, Fender Bender)
Because the solenoid reacts in milliseconds, the RSX can jump from first to second without you feeling more than a gentle "bump." Techs also call the unit a shift actuator, pressure-control valve, or gearbox electro-valve-all synonyms for the same part.

• Harsh or delayed shifts-gear changes take too long or bang into place. (Kbb.com)
• Flashing "D" on the dash and limp-home mode that locks the car in one gear. (batauto.com)
• Check-engine codes P0753 (Shift Solenoid "A" electrical) and P0974 (Shift Solenoid "A" circuit high). (Kbb.com, YourMechanic)
• No upshift out of first-especially after a cold start. (YouTube)

Dirty or old fluid lets varnish build on the solenoid plunger, making it stick. Overheating, frayed wiring, or a burnt coil can stop the valve from moving at all. A cracked O-ring lets high-pressure oil bypass and causes clutch slip. (RepairPal.com, YouTube)

1. Scan for codes. P0753 or P0974 narrow the hunt to the A-solenoid power feed. (Kbb.com, YourMechanic)
2. Measure resistance. Unplug the connector and read 12-25 ? across the pins; open or short circuits point to a failed coil. (YouTube)
3. Check fluid quality. Brown, burnt, or glittery oil signals clutch debris that can jam the valve. (ClubRSX)
4. Hydraulic test. A manual pressure gauge screwed into the 3rd-clutch port should climb when the solenoid is commanded on. (Fender Bender)

• Drain & fill about 2.5-3 qt of ATF-DW-1; catch fluid in a clean pan. (Wikipedia)
• Remove the battery tray for top access, then unbolt the solenoid cover (three 10 mm bolts). (ClubRSX)
• Torque specs: Case-to-block bolts 47 ft-lb; solenoid cover bolts 9 ft-lb. (ClubRSX)
• Calibrate fluid level. Warm engine, idle in P, then move selector through all gears before final check.

? scroll table horizontally ?

Honda's DW-1 fluid replaces older Z1 and keeps seals pliable. (Wikipedia)
Common factory part number for the main shift-solenoid set is 28015-PRM-305, useful when cross-referencing catalogs. (Acura Parts Warehouse)

Change ATF every 2-3 years under normal driving or yearly if you track the car. (ClubRSX)
Always use a new crush washer on the drain bolt. Keeping fluid fresh stops heat soak and sludgy build-up that wrecks the shift valve early.

Used transmission oil is classified as "used oil" under U.S. EPA rules; recycle it at a certified collection center-never dump it. (US EPA)
Old solenoids are mostly metal and can be recycled with mixed scrap once drained.

A bad pressure switch, torque-converter clutch solenoid, worn valve body, or damaged TCU wiring harness can mimic the same shift problems. Checking these saves unnecessary part swaps. (Transmission Parts Distributors)

Q: What does a transmission solenoid do?
A: It acts like a tiny faucet that opens or closes hydraulic passages so the gearbox can pick a gear smoothly. (Wikipedia)

Q: Where is the automatic shift solenoid on an Acura RSX?
A: On the 5-speed auto, it bolts to the top-front of the transmission, under a small cover by the battery. (ClubRSX)

Q: Which trouble codes point to a bad solenoid?
A: P0753, P0756, P0974, P0983, and related "shift solenoid A/B" or "pressure control" codes. (Kbb.com, YourMechanic, RepairPal.com)

Q: Can I drive with a faulty solenoid?
A: Short trips at low speed may be possible, but slipping or staying in one gear can overheat the transmission fast-tow it if symptoms are severe.

Q: How much does the part cost?
A: Aftermarket solenoid sets range from about $80 to $200, plus fluid and seals. Labor is 1-2 hours. (Prices vary by market.) (Wikipedia)

Q: Do I need special tools?
A: Basic sockets, a torque wrench, and a multimeter. A pressure gauge is helpful for advanced tests. (YouTube)

Q: What fluid should I use?
A: Honda genuine ATF-DW-1 (or a licensed equivalent); never mix with Dexron-III or CVT fluid. (Wikipedia)

Q: How often should the fluid be changed?
A: Every 30,000-50,000 miles, or sooner under severe service. (ClubRSX)

Q: Will a fluid flush fix a sticking solenoid?
A: Sometimes. If varnish is light, two or three drain-and-fills plus a short ride between may free the plunger. Heavy wear usually needs a new valve. (YouTube)

Q: Could a worn pressure switch set the same code?
A: Yes; Honda/Acura tech bulletins say to test or swap the 2nd/3rd clutch pressure switch before replacing solenoids. (Transmission Parts Distributors)

Q: Are RSX Type-S models affected?
A: No, the Type-S uses a 6-speed manual and has no automatic shift solenoids.

Q: What torque spec for the solenoid cover bolts?
A: 9 ft-lb. Case-to-block bolts are 47 ft-lb. (ClubRSX)

Q: How can I keep the solenoid healthy?
A: Change fluid on schedule, add an auxiliary cooler if you race, and repair any engine misfires that overheat the oil.

Q: Is it safe to rebuild the solenoid?
A: Most shops replace rather than rebuild because the tiny filter screen and coil are hard to service.