8L90 Governor Pressure Solenoid, remanufactured and ready to install. Fits the 8L90. Ships fast from the USA.
First, a note on the name: the GM 8L90 and 8L45 have no governor, so there is no governor pressure solenoid in these transmissions. What this listing actually ships is a remanufactured set of seven valve body solenoids for the 8L90, 8L45 and 8L50, the parts you are after if a Silverado, Sierra, Tahoe, Yukon, Camaro, Corvette, Colorado, Canyon or Cadillac is slamming into gear, flaring between shifts, or setting a solenoid performance code. The set is listed for the 334740BB valve body (sold less pump) with top casting 24272846, bottom casting 24274844 and cover casting 24273239, and the interchange references given for the pieces include 24272280, 24272281 and 24272282.
There is no shift valve train in the old sense. GEARS Magazine counts nine solenoids on the 8L90 valve body: seven variable force pressure control solenoids and two three-port on/off units (S8 default control and S9 boost). Each pressure control solenoid feeds signal oil to its own clutch control valve, so one solenoid effectively runs one clutch: S1 the 1-2-7-8-reverse clutch, S2 1-2-3-4-5-reverse, S3 1-3-5-6-7, S4 2-3-4-6-8, S5 4-5-6-7-8-reverse, S6 line pressure and S7 the converter clutch. Some are normally high and some normally low, every one measures 4.5 to 5.5 ohms, and they flow differently by position, which is why they must go back in the bore they came from. This kit is sold as the seven solenoids the valve body needs; if your fault traces to S8 or S9, check the pieces against your old ones before you start.
Read which clutch is misbehaving from the gear in which it happens, then compare commanded versus actual pressure or slip on a scan tool and check resistance at the case connector. Sonnax documents a valve-side trap on this family: a .426 in or .443 in clutch control valve installed where the common .531 in valve belongs produces delayed engagement, sloppy upshifts and P0722 that look exactly like a bad solenoid, so a previously rebuilt valve body deserves a look. Shudder at 25 to 80 mph with no codes is usually the fluid problem GM addressed in bulletin 18-NA-355, not a solenoid. Our 8L90 shift solenoid symptoms guide lays out the electrical tests, and the 8L90 valve body testing guide covers the casting and valve faults that mimic solenoid failure.
The listing covers the Chevrolet Camaro, Corvette, Silverado 1500 and Tahoe and the GMC Sierra 1500 and Yukon for 2014-2023 with the 8L90 or 8L50, the Cadillac CTS, ATS, Escalade and CT6 for 2015-2020 with the 8L45 or 8L90, and the 2017-2023 Colorado and Canyon with the 8L45. GM changed parts during the run, so match the numbers on your old solenoids and valve body castings to the ones above, or send us your year and VIN and we will check it before it ships. Every other part we carry for this family is in our 8L90/8L45 collection.
Drop the pan, remove the filter, unplug the harness and lift the valve body out. Work one bore at a time so no solenoid changes position, lube the O-rings with clean fluid and seat each retainer fully. Inspect the harness while it is out; brittle conduit or a damaged connector is the time to fit a new 8L90 internal wiring harness, and a fresh filter and steel pan gasket kit belongs on any valve body job. Refill with DEXRON HP (Mobil 1 Synthetic LV ATF HP); GM lists a 7.4 quart fluid change, then set level hot at the check plug. The step most installs skip: the TCM stores characterization data for each solenoid, tied to the part unique number on the valve body, so after changing solenoids GEARS says to reprogram the TCM through GM service programming and then run the service adaptive relearn. Skip it and you can create the harsh, erratic shifts you were trying to fix.
| Fits | 8L90 |
| Part type | Governor Pressure Solenoid |
| Condition | Remanufactured |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
No. The 8L90 and 8L45 have no governor. This listing is a remanufactured set of seven valve body solenoids for the 8L90, 8L45 and 8L50, which is what the old title was trying to describe.
Listed fitment is the 2014-2023 Camaro, Corvette, Silverado 1500, Tahoe, Sierra 1500 and Yukon with the 8L90 or 8L50, the 2015-2020 Cadillac CTS, ATS, Escalade and CT6, and the 2017-2023 Colorado and Canyon with the 8L45. Match your solenoid and casting numbers or send us your year and VIN.
Yes, on this family. The TCM holds characterization data for each solenoid. GEARS Magazine says to download the data and reprogram the TCM through GM service programming whenever solenoids are changed, then run the adaptive relearn.
No. They operate differently by position, some normally high and some normally low, with different flow rates. Install each one in the location its original came out of.
Pressure control solenoids in this unit measure 4.5 to 5.5 ohms. Check resistance at the case connector, then compare commanded and actual values on a scan tool in the gear where the problem shows up.
DEXRON HP, sold as Mobil 1 Synthetic LV ATF HP. GM lists a 7.4 quart fluid change for the 8L90 and 8L45. Set the level hot at the check plug.
