Replaces all seven solenoids in the GM 8L90 valve body at once, for units with harsh shifts, converter shudder or a limp-mode code.
When a GM 8-speed Hydra-Matic - the 8L90 behind the Silverado, Tahoe, Yukon, Escalade, Camaro and Corvette, or the lighter-duty 8L45/8L50 behind the Colorado, Canyon, ATS, CTS and similar - starts banging the 1-2 shift, flaring on the 4-5, cycling the torque converter clutch at light throttle, or drops into limp holding one gear, the cause is almost always a solenoid rather than a mechanical failure. This kit replaces all seven solenoids in the valve body at once: the GM references on the pieces are 24272278, 24272280, 24272281 and 24272282, and the same parts service the 8L90, 8L45 and 8L50 valve bodies.
These transmissions carry seven solenoids in the control valve body - six pressure-control (VFS) circuits plus the torque converter clutch solenoid - and Sonnax's circuit documentation for this family maps each one to a specific clutch or pressure function and the gears it affects. Heat and fluid hours change how a VFS solenoid meters pressure well before the valve body casting itself wears, and because every solenoid in that assembly has run the same hours on the same fluid, a scan tool that hangs a code on one circuit is rarely isolating a problem unique to that one solenoid. Replacing a single unit commonly buys a few months before the next circuit sets a code, which is why this kit swaps the full set in one job.
Sonnax's own clutch control valve and solenoid documentation for this family describes a specific trap: a mismatched valve land diameter (.426 in or .443 in against the common .531 in) can produce the same delayed-engagement and sloppy-upshift symptoms, and stored codes like P0722, as a failing solenoid - so a thorough scope or pressure test of the affected circuit before replacement is worth the time. Our 8L90 shift solenoid symptoms and replacement guide and the broader 8L90 common problems and fixes guide walk through separating a solenoid-circuit fault from a valving or fluid problem on this transmission family.
Listed fitment covers the Silverado 1500 and Sierra 1500 2015-up, Colorado and Canyon 2015-up (gas), Yukon, Yukon XL, Escalade and Escalade ESV 2015-2017, Camaro 2016-2019, Corvette 2015-2019, Cadillac ATS and CTS 2016-2019, CT6 2016-2018, XT4 2019, CT4 2020-2021, Malibu XL 2.0T and Equinox 2.0T 2016-2019, Buick LaCrosse and Envision 2.0T, and Express and Savana 2017-up with the 2.8L diesel. If a scan shows a casting-level fault rather than a solenoid circuit, our 8L90/8L45 parts collection carries the full valve body and shift kits for this family.
Drop the pan, pull the filter, unplug the internal harness and unbolt the valve body to reach the solenoids, which are retained by small clips or brackets on the casting. Pull and replace one bore at a time, since the solenoids in this valve body are not interchangeable position to position, and lubricate the new O-rings with clean fluid before seating each one so the connector tab lines up with the harness. Refill with Mobil 1 Synthetic LV ATF HP (DEXRON HP) and set the fill level by fluid temperature rather than a dipstick guess, since this family is sensitive to fill level. Pair the kit with a fresh 8L90 internal wiring harness if the harness connectors are showing heat damage, since a marginal connection can reproduce the same codes right after the swap.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
All seven solenoids used in the GM 8L90, 8L45 and 8L50 valve body - six pressure-control (VFS) solenoids plus the torque converter clutch solenoid - under GM references 24272278, 24272280, 24272281 and 24272282.
Every solenoid in the valve body has run the same fluid and heat cycles. Replacing only the one circuit that set a code commonly buys a few months before the next one fails, so this kit swaps the whole set in one job.
Banging or harsh 1-2 and 2-3 shifts, a flared or delayed 4-5 upshift, torque converter clutch cycling or shudder at light throttle, and limp mode with a VFS or TCC circuit code.
Silverado and Sierra 1500 2015-up, Colorado and Canyon 2015-up (gas), Yukon, Escalade 2015-2017, Camaro 2016-2019, Corvette 2015-2019, Cadillac ATS, CTS, CT6, XT4, CT4, Malibu XL and Equinox 2.0T, Buick LaCrosse and Envision 2.0T, and Express/Savana 2.8L diesel 2017-up.
No. Each solenoid must go back into the same bore position it came from - they are not interchangeable position to position in this valve body.
Mobil 1 Synthetic LV ATF HP (DEXRON HP), set to level by fluid temperature rather than a dipstick reading, since this transmission family is sensitive to fill level.
