Complete AW55-50SN valve body with the solenoid pack installed, for Volvo, Saab, Nissan and Saturn units with harsh shifts, slipping or limp mode.
If your Volvo, Saab, Nissan Maxima or Altima, or Saturn with the AW55-50SN five-speed automatic is shifting harsh, flaring on the 1-2, slipping on the 3-4, dropping into limp mode and holding one gear, or shuddering under light throttle from the torque converter clutch, this complete AW55-50SN valve body with the solenoid pack already installed swaps the whole hydraulic and electrical assembly in one job instead of pulling eight solenoids off a core and testing them one at a time.
The AW55-50SN, also sold as the AW55-51SN and RE5F22A, is Aisin Warner's electronically controlled 5-speed front-wheel-drive transaxle used across 2001-2010 Volvo, Saab, Nissan, Opel/Saturn and Suzuki models. The valve body is the unit's hydraulic brain - it routes line pressure through precision bores and spool valves to apply each clutch and band in sequence, while the shift and pressure-control solenoids mounted on it carry out every shift command the transmission control module sends, including torque converter clutch apply. Sonnax's diagnostic documentation for this family notes that the solenoid modulator valve feeds and caps pressure to the linear solenoids, and that worn bores show a distinctive discoloration pattern at the bore ends - a direct sign of the wear this complete assembly is built to replace.
The failure in this family is almost always electrical rather than mechanical - the solenoids degrade with heat and mileage, and by the time one fails on a scan tool the rest are the same age and the same miles, which is why shops replace the whole valve body and solenoid pack together instead of chasing one circuit at a time. Our AW55-50SN service guide covers the bore wear patterns this family shows and which circuits tend to fail first.
Pull codes first - a stored circuit code for a specific shift or pressure-control solenoid points straight at this assembly. If the complaint is a shift-quality issue with no codes at all, check fluid level and condition before assuming the valve body, since this family is sensitive to running the wrong ATF spec.
This assembly carries the OEM references AW55-50SN, AW55-51SN and RE5F22A, and is listed for Nissan Maxima and Altima, Saab, Saturn and Volvo applications from 2004 to 2009. Because the same transmission family was used across a wide range of brands and model years with more than one solenoid revision, match your old unit's connector and casting number against this listing, or send us your year, make, model and VIN before ordering. If you only need the valve body without the solenoids installed, see our standalone AW55-50SN valve body instead.
Drop the pan, pull the filter, unplug the internal harness connector, and back out the valve body bolts in the factory order. Keep the checkballs and separator plate orientation straight on the way apart, and torque the new assembly down evenly working from the center out so the separator plate is not distorted. Refill with JWS 3309-spec ATF - fluid documentation for this spec cross-references it against the Volvo and GM part numbers used on this exact transmission family - and let the TCM relearn its shift adapts over the first several drive cycles before judging shift quality. Since the solenoids are already installed on this assembly, add a separate AW55-50SN TCC solenoid only if you are isolating a converter-clutch-specific code after this replacement, and consider our AW55-50SN overhaul kit if the pan and filter are overdue for service at the same time.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The AW55-50SN family, also sold under the AW55-51SN and RE5F22A references, covers Nissan Maxima and Altima, Saab, Saturn and Volvo applications from 2004 to 2009, as well as other Opel and Suzuki models that used the same Aisin Warner transaxle across 2001-2010.
Solenoid failures on this family are age and heat related, so by the time one solenoid fails on a scan tool the rest are the same age and miles. Replacing the complete assembly with the solenoid pack installed removes the whole wear group at once instead of chasing individual circuits.
JWS 3309 ATF. Use that exact specification on refill - this transmission family is sensitive to the wrong fluid spec, which can itself produce harsh shifts or TCC shudder.
Yes. The transmission control module adapts its shift pressures over time, so after installing this assembly drive through a range of light and moderate throttle shifts over several drive cycles to let it relearn.
In most cases yes, when the complaint comes with a stored shift or pressure-control solenoid code, since those circuits are exactly what this assembly replaces. If the slip is present in every gear with no codes at all, check fluid condition and the torque converter first.
