AW55-50SN Pressure Control Solenoid, new and ready to install. Fits the AW55-50SN. Ships fast from the USA.
If your Volvo, Saab, GM crossover or Nissan with the Aisin Warner five-speed thumps into Drive, flares on the 2-3 shift, or surges in and out of lockup on the highway, the three linear pressure solenoids are one of the first parts a transmission shop looks at. This listing is a new Rostra three-piece set for the AW55-50SN and its relatives: SLT, SLS and SLU, each color-coded, supplied with the mounting bracket and an instruction sheet. The set is rated at 5.3 ohms per solenoid and is sold as a matched group, because these solenoids are calibrated to work together. It ships from the USA.
The AW55-50SN picks gears with simple on/off shift solenoids, but it decides how hard each clutch and band is applied with these three linear solenoids. The TCM pulses them rapidly and varies the duty cycle, so the output pressure rises and falls smoothly instead of switching on and off. The color code on this set makes the jobs easy to keep straight:
Start with the fluid. Sonnax notes that both low fluid and overfill on this unit cause erratic pressure and poor linear solenoid control, which can push the TCM into its high-pressure strategy on its own. Then check each solenoid at the connector with a meter (Rostra rates these at 5.3 ohms; Sonnax gives 5.0 to 5.6 ohms for the family), and if you have a gauge, compare pressures with the published numbers. C-1 clutch pressure should step to about 25 psi and then 50 psi within half a second of selecting Drive; if it jumps straight to around 160 psi, the unit is likely in failsafe and engagement will be abrupt. On the 2-3 shift, B-4 servo pressure should follow C-1 and never sit more than 10 psi below it. Our solenoid multimeter test guide walks through the resistance check, and the AW55-50SN service guide covers the valve body wear that can look exactly like a bad solenoid.
This set is listed for the AW55-50SN five-speed front-wheel-drive automatic used in many GM cars and crossovers from 2002 to 2011, and in Nissan, Saab, Suzuki and Volvo models from 2002 to 2015. The same Aisin design also carries the AW55-51SN, AF33-5 and RE5F22A names depending on the vehicle maker. Year alone is not enough to match these solenoids. Sonnax documents early and late SLT and SLS versions with different bracket widths and manifold lengths, and a late SLT with its connector facing down that needs the matching harness. Compare your old solenoids, bracket and connector direction against the photos, or send us your year, model and VIN before ordering. Other parts for this family are on our Aisin transmission parts page.
If the solenoid modulator bore or regulator bores are worn, new solenoids will not cure the problem; a remanufactured AW55-50SN valve body is the better fix. If you are already inside the unit for a full overhaul, add the AW55-50SN master rebuild kit.
| Fits | AW55-50SN |
| Part type | Pressure Control Solenoid |
| Condition | New |
| Brand | Rostra |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The connectors are color-coded: blue is SLT (line pressure and forward engagement), green is SLS (clutch apply and release timing) and black is SLU (torque converter clutch plus several shift events). The bracket is included.
No. This is the three-piece linear pressure solenoid set only. If you want every solenoid in the valve body replaced at once, look at our eight-piece AW55-50SN solenoid set.
These solenoids are listed for the AW55-50SN family, which includes the versions called AF33-5 and RE5F22A. Because early and late SLT and SLS solenoids use different brackets and connector positions, compare your old parts or send us your year, model and VIN.
About 5.3 ohms each. Sonnax lists 5.0 to 5.6 ohms for this family. A reading far outside that range points to a failed coil or a wiring fault.
When the TCM sees a pressure control fault, a bad speed signal or aerated fluid, it commands high line pressure to protect the clutches. Engagements and the 2-3 shift become abrupt until the cause is fixed and the codes are cleared.
Yes. Clear codes and drive several cycles, or run the adaptation reset with a capable scan tool, so the TCM can relearn shift pressures with the new solenoids.
