Shop 6L90 Valve Bodies & Modules →
The 6L90 is the heavy-duty version of GM's 6L series six-speed longitudinal automatic. It went behind big-block gas and small-block V8 combinations in the Silverado and Sierra 2500HD and 3500, Tahoe, Suburban, Yukon XL, Escalade, Express and Savana vans, and the Camaro ZL1. It is a strong unit. It also has one design decision that changes the entire economics of a solenoid repair, and if nobody explains it to you before you get a quote, the number looks insane.
On the 6L90 there is no such thing as buying a shift solenoid from GM. The shift and pressure control solenoids live inside the TEHCM, the Transmission Electro-Hydraulic Control Module, which packages the transmission control module and the solenoid assembly into one serviced part bolted to the valve body inside the pan. GM sells the TEHCM. It does not break it down into pieces. That is why a code that reads like a $60 part turns into a four-figure repair order.
Cost, short version: $900 to $1,800 at an independent shop for a remanufactured TEHCM installed, fluid, filter and programming included. $1,400 to $2,400 at a dealer. $430 to $1,040 in parts if you do the wrenching yourself, plus whatever a shop charges you to program the module.
Cost Breakdown
| Repair | DIY Parts | Independent Shop | GM Dealer |
|---|---|---|---|
| Reman TEHCM, installed with fluid and filter | $430 – $1,040 | $900 – $1,800 | $1,400 – $2,400 |
| New OEM TEHCM (part only) | $700 – $1,200 | — | $900 – $1,500 |
| Individual aftermarket solenoid swapped onto TEHCM | $60 – $150 each | $550 – $950 | Not offered |
| Valve body with control module, complete | $550 – $1,300 | $1,100 – $2,200 | $1,900 – $3,000 |
| Pan drop, filter and DEXRON VI only | $80 – $150 | $250 – $420 | $350 – $550 |
| Programming and adaptive relearn (if done separately) | Not practical DIY | $120 – $250 | $150 – $300 |
Wrench time is 2.5 to 4.0 hours. Two-wheel-drive half-ton platforms with room under the pan are at the low end. A 2500HD with a transfer case, skid plate and exhaust in the way, or an Express van where you are working through the floor access and around the frame, pushes toward four. Add 30 to 60 minutes on top for programming and the relearn drive cycle.
The Codes
| Code | Meaning | Typical Cause on a 6L90 |
|---|---|---|
| P0751 | Shift solenoid A performance, stuck off | Solenoid inside the TEHCM, or low line pressure masking as a stuck solenoid |
| P0752 | Shift solenoid A stuck on | Debris holding the valve, or a failed solenoid winding |
| P0776 | Pressure control solenoid B stuck off | Slipping or flaring shift; solenoid, worn valve bore, or low pressure |
| P0796 | Pressure control solenoid C stuck off | Same family of causes as P0776, different clutch circuit |
| P0842 / P0843 | Transmission fluid pressure switch A circuit | Pressure switch inside the TEHCM assembly |
| P0716 / P0717 | Input speed sensor performance or no signal | Sensor or the internal pass-through connector at the case |
| P0894 | Transmission component slipping | Mechanical. A clutch pack is not holding. Not a solenoid job |
| P0700 | TCM requested MIL | Informational only. The real code is stored in the transmission module |
The 6L90 and the 6L80 share the same code set and the same TEHCM architecture, so the diagnostic writeups cross over. If you are chasing a specific code, we have dedicated pages for P0776, P0796 and P0894 that apply to the 6L90 as well.
What the driver actually notices
- Harsh 1-2 or 2-3 upshift, worse cold, sometimes settling once fluid warms.
- Flare between gears, rpm rising then dropping as the next clutch catches late.
- Stuck in one gear with the light on. Failsafe. The truck moves but will not shift.
- Shudder at steady light throttle, typically 40 to 55 mph. That is the torque converter clutch, covered on our 6L90 shudder fix page.
- Delayed engagement into drive or reverse, often the first sign that line pressure is dropping.
TEHCM Versus Individual Solenoid: The Real Choice
You have three practical paths on a 6L90 with a solenoid code, and they are not equal.
1. Remanufactured TEHCM
The default and the one most shops will do. You get a module that has been disassembled, had every solenoid and pressure switch replaced or tested, and been functionally verified on a bench. It comes with a warranty. Cost is $350 to $900 for the module. This is the right answer on a truck with over 120,000 miles or one that tows, because every solenoid inside that module has the same hours and heat cycles on it and pulling the pan twice is not free.
2. Individual solenoid swapped onto your existing TEHCM
Aftermarket suppliers sell single 6L90 solenoids for $60 to $150. A technician who knows the assembly can pull the one failed unit and replace it. This is legitimate work and it saves real money on a low-mileage truck with one clean electrical code and healthy fluid. What it does not give you is a bench-tested module. If the pressure switch section is also drifting, or a second solenoid is marginal, you are going back in.
3. Complete valve body with the module attached
The answer when you have pressure-related codes that survive a new module, or when the valve bores are worn. Bore wear is a known 6L90 issue, particularly in the pressure regulator and TCC regulator circuits, and no amount of new solenoids fixes a bore that is bleeding pressure past a worn valve. A complete valve body assembly runs $550 to $1,300. A valve body repair kit in the same circuits is the cheaper route if the shop is comfortable reaming and installing oversized valves.
One diagnostic step that decides between these: check line pressure with a gauge before you buy anything. A 6L90 with low commanded line pressure will set solenoid performance codes even with perfectly good solenoids, because the module commands a pressure and the hydraulics never deliver it. Low pressure comes from a worn pump, a bad pressure regulator valve, or a leaking circuit, and a $900 module does not touch any of those.
Where to Buy 6L90 Solenoid and Valve Body Parts
Valve bodies with the transmission control module installed, OEM control valve bodies, valve body repair kits, pressure regulator valve kits, filters, pans and full master rebuild kits for the GM 6L80 and 6L90. Same-day ship on orders before 2pm Eastern.
Shop 6L90 Valve Bodies → Core Transmission Parts →The Job: Pan Drop, Filter and TEHCM
The whole repair happens through the pan. There is no need to drop the transmission. Rough sequence, and the details that bite people:
- The 6L90 pan uses a reusable bonded gasket, a rubber-molded seal on the steel pan rather than a paper gasket. It can be reused if it is clean and undamaged, but if the pan is dented at a bolt hole or the seal is hardened, replace the pan. A warped 6L90 pan flange is a permanent slow leak.
- Drop the pan evenly. There is no drain plug on many of these. Loosen from one corner and let it tip into the drain pan.
- Read the pan. Gray paste on the magnet is normal. Black fibrous material is clutch friction and changes the conversation. Aluminum or bronze chips mean pump or bushing wear and no module is going to fix that.
- Filter comes out with a pull. Make sure the filter seal comes out with it and is not left stuck in the pump bore. Installing a new filter on top of an old seal is a classic no-pressure comeback.
- Disconnect the internal pass-through connector at the case before unbolting the TEHCM. Release the lock, do not pull on the wires.
- TEHCM bolts are small and go into aluminum. Roughly 11 Nm, about 97 inch-pounds. Pan bolts are around 12 Nm, about 106 inch-pounds. Use an inch-pound torque wrench for both. Overtightening the pan bolts is what warps the flange.
- Fluid is DEXRON VI, nothing else. About 7 quarts for a pan drop and filter, roughly 11.5 to 12 quarts total including the converter. Details and the fill procedure are on our 6L90 fluid change cost page, and fluid choices on best transmission fluid for the 6L90.
- Set the level at the check plug, engine running, transmission in park, fluid inside the specified temperature window. Most 6L90 applications are sealed with no dipstick, so you need a scan tool reading transmission fluid temperature.
Step-by-step photos and torque notes for the removal itself are in our how to replace a 6L90 shift solenoid walkthrough.
Programming and Relearn: Do Not Skip This
This is the part that separates a repair that works from one that comes back. A replacement TEHCM must be programmed and configured to the vehicle. The module carries the transmission calibration and the vehicle-specific configuration, and it also stores the adaptive shift data the TCM has been learning since the truck was new.
What has to happen:
- Program the module to the VIN and the correct transmission calibration. A dealer does this with the factory service programming system. Many independent shops have equivalent capability. Some remanufacturers will ship the module pre-programmed if you give them the VIN off the order, which is worth doing if you are the one installing it.
- Reset the transmission adaptive values. A new module starting with stale or default adapts shifts badly.
- Drive the relearn cycle. Light to moderate throttle, let it take every upshift and downshift, including the 1-2 through 5-6 range, at varying loads. Twenty to forty miles of mixed driving usually settles it. Shift quality that is firm on day one and normal by day three is expected behavior, not a failure.
If a shop quotes you a TEHCM job and the estimate does not mention programming or relearn, ask about it before you authorize the work. A module installed without configuration will either not come out of failsafe or will shift hard enough that you think the transmission is broken.
What Else to Do While the Pan Is Off
- New filter and, if the seal or flange is questionable, a new pan. You are already there.
- Inspect the internal harness and pass-through connector for chafing and corrosion. A perfect module on a bad connector still sets codes.
- Consider a deep pan if the truck tows. More fluid volume means lower operating temperature, and heat is what kills these units.
- Check the cooler lines and cooler flow. Restricted flow raises temperatures across the board.
- Address bore wear now if the shop finds it. A pressure regulator valve kit installed during the same teardown costs a fraction of doing the job twice.
If the diagnosis has already moved past electronics into slipping clutches, our 6L90 transmission problems and cost and 6L90 rebuild cost pages cover what a full teardown runs, and 6L90 rebuild parts lists what a proper kit includes. For the differences between the 6L80 and 6L90 as they affect parts interchange, see 6L80 vs 6L90.
FAQ
How much does 6L90 shift solenoid replacement cost?
A remanufactured TEHCM installed at an independent shop runs about $900 to $1,800 including the module, DEXRON VI, a filter, 2.5 to 4.0 hours of labor and programming. A dealer is usually $1,400 to $2,400. DIY parts are $430 to $1,040, but you still need programming done.
Can you replace individual shift solenoids on a 6L90?
GM does not sell them separately. The solenoids are part of the TEHCM assembly, which combines the control module and solenoid body into one serviced unit. Aftermarket rebuilders sell individual solenoids that can be swapped onto the TEHCM, which is a real option on a low-mileage truck with one clean code, but it does not give you a bench-tested module.
What does P0776 mean on a 6L90?
Pressure control solenoid B stuck off. It shows up as a slipping or flaring shift and often a limp mode event. Causes are the solenoid, low line pressure, or a worn valve bore bleeding pressure. Check fluid level, fluid condition and line pressure before condemning the module.
Does a new 6L90 TEHCM need programming?
Yes. It has to be programmed and configured to the VIN and transmission calibration, and the adaptive values have to be reset and relearned. Skipping it leaves you with harsh shifts, false codes, or a transmission that will not exit failsafe.
How long does 6L90 solenoid replacement take?
About 2.5 to 4.0 hours of wrench time, plus 30 to 60 minutes for programming and the relearn drive cycle. Heavy-duty four-wheel-drive platforms and vans are at the top of that range.
How much fluid does a 6L90 take for a pan drop?
About 7 quarts of DEXRON VI for a pan drop and filter change. Total capacity with the converter is roughly 11.5 to 12 quarts. Most applications are sealed with no dipstick, so the level is set at the check plug within a specified temperature window.
Will a bad solenoid cause 6L90 limp mode?
Yes. A stuck or electrically failed solenoid makes the TCM command failsafe, which holds one gear with no converter lockup. Driving that way builds heat and can cost you clutch packs, so treat it as stop-and-diagnose rather than something to live with.