P2761 is one of the few 10L80 codes that is genuinely honest with you. The SAE description is "Torque Converter Clutch Pressure Control Solenoid Control Circuit/Open," and that is exactly what it means: the TCM tried to push current through the TCC solenoid driver and did not get the electrical feedback it expected. This is a circuit code. It is not a slip code and it is not a shudder code. Nothing in it says the converter is bad, the clutch is burnt, or the valve body is worn.
Check the code number on GM trucks first. GM's own 2020 OBD certification tables for the T87A 10-speed rear-drive TCM do not list P2761 at all. On that controller the TCC solenoid control circuit is monitored as "Pressure Control Solenoid H": P281B for an open (more than 200K ohms between signal and controller ground, failing 0.30 seconds out of a 0.50 second sample, Type B, two trips), P281D for a short to ground (Type A, one trip) and P281E for a short to voltage (Type B, two trips), all enabled with battery voltage between 9 and 32 volts. If your scan tool shows P281B on a 2020-up 10L80, it is the same open-circuit fault this article diagnoses, under GM's numbering. Generic code readers and some aftermarket tools translate it to the SAE P2761 description, which is why both numbers turn up for the same truck.
That distinction matters because P2761 gets treated like a converter complaint constantly. A customer describes lockup that never happens and fuel economy that fell off a cliff, the scan tool shows P2761, and somebody quotes a converter and a rebuild. Meanwhile the actual fault is often a few inches of chafed wire or a connector that never fully seated after the last pan drop.
How the 10L80 TCC solenoid circuit is built
The GM 10-speed uses eight pressure-regulating control solenoid valves in the lower valve body. Transmission Digest's Mike Souza lays out the assignments: solenoids 1 through 6 handle the clutch-to-clutch shifts, solenoid 7 is the line pressure control solenoid (a normally high variable force solenoid), and solenoid 8 is the TCC solenoid, a normally low variable force solenoid. Normally low means no current equals no output pressure, which is why a dead TCC circuit leaves the converter clutch released rather than locking it up solid.
The current-to-pressure relationship is not on/off. ATRA's GEARS, documenting the Ford side of this same joint-venture 10-speed architecture, describes the TCC variable force solenoid producing very low output pressure at roughly 50 mA and high output pressure at roughly 850 mA, with the module sweeping between those to control converter clutch slip rather than slamming the clutch in and out.
The detail that explains why P2761 sets when the TCC is not even commanded
This is the part worth memorizing. Per GEARS, the control current for the LPC and TCC solenoids does not go to zero when the circuit is commanded low. An idle current stays in the circuit so the module can monitor feedback and prevent back-EMF.
That idle current is the monitor. Because a small current is always flowing through the TCC driver, the module can watch circuit integrity continuously instead of only during a lockup event. So the truck can set P2761 sitting at idle in the bay, in Park, with the converter clutch nowhere near being commanded. Techs who assume the code only sets during a lockup attempt burn an hour trying to reproduce it on a road test that was never required.
It also kills a common shortcut: you cannot rule out an open by seeing "some voltage" on a meter. Transmission Digest's Chris Adams scoped all eight solenoids on a 10R80 — the Ford twin of this unit — and made the point directly. On these transmissions you will read voltage on a DVOM at times the application chart says the solenoid is off, and that will lead you down the wrong path. He also found the control is not a clean square wave: at light-load cruise the TCC solenoid ran 35 to 45 percent duty cycle at 2.6 to 3.5 kHz, with both duty cycle and frequency moving. Use a scope on this circuit, not a meter.
The actual causes, ranked by what shows up
1. External wiring and the case connector
The 10-speed family put the transmission control module back outside the unit, which Adams notes makes this kind of testing far easier than it was when the module was buried under the pan. The tradeoff is more exposed circuit between the module and the solenoid. Start there.
- The transmission case pass-through connector. Backed-out terminals, spread female contacts, and pushed-out pins are the number one finding. Pull the connector and inspect each cavity with a pick and a light, not just by eye.
- Chafe points along the harness run. Anywhere the harness crosses a bracket edge or rests against the case, look for insulation worn down to copper. A wire chafed to bare metal against the case reads as an intermittent short or open depending on how the truck is loaded.
- Fluid intrusion into the connector. ATF wicking up the harness corrodes terminals and raises resistance until the driver reports an open. If the connector body is wet, the internal seal is the real repair.
- Recent service. If the code appeared right after a pan drop, filter change, or valve body R&R, the connector or the internal harness is the first suspect, not the solenoid.
2. The internal harness and the solenoid itself
Once the external circuit checks out, the fault is inside. Drop the pan and inspect the internal harness where it routes across the valve body, then check the solenoid terminals themselves. Measure solenoid resistance at the solenoid, not through the case connector, so you are testing one component instead of a whole circuit. An open winding reads infinite; a solenoid that has cooked reads far off its neighbors. Compare all eight — on a healthy valve body the TCC solenoid should sit in the same neighborhood as the other pressure-regulating solenoids of its type.
3. Physically loose solenoids in the casting
This one is specific to the 10L80 and worth checking while you are in there. Sonnax lists solenoid stabilization parts for this unit — the 105740-01K clip insert and the 105740-19K retainer — specifically to cure loss of shift solenoid control pressure, poor shift quality, TCC apply and release concerns, and damaged valve body casting. A solenoid that can move in its bore works its terminals and eventually beats out the casting. Fix the electrical fault without fixing the retention and you have bought yourself a comeback.
4. The TCM driver
Last, not first. A failed output driver inside the module is real but uncommon, and it is a diagnosis of exclusion. Prove the harness and the solenoid are good before you condemn a module that has to be programmed after replacement anyway.
Do not confuse P2761 with a shudder complaint
Plenty of 10L80 trucks come in with converter clutch symptoms and no P2761. If the code is not there, the electrical circuit is not your problem, and GM has published a decision tree for exactly that situation.
GM Service Bulletin 22-NA-015 (September 2023) covers shudder, shake, or vibration from roughly 25 to 50 mph under steady to lightly accelerating throttle on 2020-2024 Silverado, Sierra, Tahoe, Suburban, Yukon and Escalade models. Its first instruction is to resolve any stored DTCs and re-evaluate the vehicle before proceeding — which is precisely where a P2761 gets fixed and the shudder complaint leaves with it.
The bulletin's GDS graphing tips are the useful part, because they separate failures that feel identical from the driver's seat:
| What the data shows | GM's read | Direction |
|---|---|---|
| Shudder present in D but not in Manual L9; throttle typically under 10 percent; engine torque under 100 Nm; TCC slip speed at or near 0; TCC pressure command held at 100 kPa | TCC solenoid / valve body concern | Replace the valve body |
| Shudder present in both D and L9; typically under 15,000 miles (24,000 km); transmission ISS follows engine speed; engine torque relatively consistent within about ±25 Nm | TCC solenoid drift — valve body | Replace the valve body |
| TCC pressure control steady, TCC slip elevated, engine RPM rises at the shudder point while transmission ISS stays steady, torque and throttle steady | Torque converter | Replace the torque converter |
| Engine torque swinging more than about ±25 Nm with no shift active and throttle relatively constant, while engine speed and transmission ISS track each other | Engine concern, not transmission | Diagnose the engine |
Two practical notes from that bulletin. First, run the test drive in Manual L9 so Dynamic Fuel Management is disabled — DFM produces a genuine low-speed vibration that GM says should be deemed a normal characteristic of the design, and chasing it costs parts. Second, a shudder present in D but gone in L9 points at the valve body, while one present in both does not.
10L80 Shift Solenoid Kit — GM OEM
When the fault turns out to be the solenoid rather than the harness, this is the GM-sourced control solenoid set for the 10L80. Remember that replacing solenoids on this unit means the TCM has to be programmed with the new solenoid performance data afterward — budget for the programming step, not just the parts.
See the GM OEM solenoid kit →The programming step people skip, and the comeback it causes
You cannot bolt in a solenoid on this transmission and drive away. Souza documents the reason: every GM 10-speed control solenoid valve is flow tested after assembly, with current swept up and then back down across the coil winding, and the resulting current-versus-pressure data points are saved to a numbered file. That file number is marked on the solenoid valve housing end or on the valve body itself, and the data file lives on GM's Techline Information System.
The TCM has to be programmed with that solenoid performance data whenever you replace:
- the transmission assembly
- the lower control valve body assembly with solenoid valves
- the transmission control module
- one or more individual solenoids
Skip it and the module commands currents calibrated for hardware that is no longer in the truck. On the TCC circuit specifically, that means apply pressure that is wrong for the solenoid actually installed, which reads to the customer as shudder, harsh lockup, or slip on a transmission you just repaired correctly. GEARS adds a related point from the Ford side of the family that applies equally here: these solenoids are calibrated from the factory and are not interchangeable, and a replacement has to match the band number of the solenoid it replaces. Our adaptive relearn guide covers what happens once the programming is done.
Fluid, and the one call to make before you replace a unit
The 10L80 takes DEXRON ULV and nothing else. GM TechLink's 2025 transmission capacities chart lists the fluid change capacity at 7.7 L / 8.1 qt for the 10L80 across RPO codes MQB, MQC, MHT, MI2 and MHS. Ultra low viscosity is not a marketing tier — the converter clutch control on this unit is calibrated around that viscosity, and a heavier LV fill changes lockup behavior in ways that read as a transmission fault.
The other thing to know before a unit gets replaced: GM has had 10L80 assemblies on parts restriction. Preliminary Information bulletin PIP5593A put 10L80 transmission part numbers 24282946 and 24294934 on restriction through the GM Product Quality Center effective 09/20/18, and directs that if diagnosis has led to replacing the transmission assembly, the shop contacts the PQC at 866-654-7654 to discuss the diagnostics behind that decision — and specifically does not clear any DTCs prior to that contact. Clear codes out of habit on a warranty 10L80 and you have destroyed the evidence the PQC is going to ask for.
The repair order that works
- Record freeze frame and all module codes before touching anything. Do not clear.
- Wiggle test the external harness and case connector with the scan tool watching the TCC solenoid command and circuit status. An intermittent that reappears on a wiggle ends the diagnosis right there.
- Scope the TCC driver at the module and again at the case connector. Look for the varying duty cycle and frequency described above, not a clean square wave. A good pattern at the module and nothing at the connector puts the fault between them.
- Measure solenoid resistance at the solenoid and compare it against the other control solenoids in the body.
- Check solenoid retention in the casting and address it with the Sonnax stabilization parts if anything moves.
- Program the solenoid performance data after any solenoid, valve body, TCM or transmission replacement, then relearn.
- Verify with a road test in Manual L9 to keep DFM out of the picture while you confirm lockup applies and releases cleanly.
Preventing the next one
Most repeat P2761s trace back to how the last repair was closed out. Route the harness clear of bracket edges and seat the case connector until it locks, both times. Replace a connector seal that has been wet with ATF rather than reusing it. Keep the correct DEXRON ULV in it at the right level so the converter clutch is not working harder than it should. And when a solenoid or valve body goes in, do the programming. That single step is the difference between a repair that holds and one that comes back looking like a converter problem.
FAQ
Does P2761 mean my torque converter is bad?
No. P2761 is an electrical circuit code that reports the TCM did not get the expected feedback through the torque converter clutch solenoid driver. It says nothing about the converter itself or about clutch condition. GM's own converter diagnosis for shudder complaints, in bulletin 22-NA-015, is a separate data-driven procedure that looks at TCC slip speed and TCC pressure command, and it starts by telling you to resolve stored DTCs first.
Why did P2761 set while the truck was just idling in Park?
Because the TCC circuit is monitored continuously, not only during lockup. The control current for the TCC solenoid never drops to zero when the circuit is commanded off; an idle current remains so the module can monitor feedback and prevent back-EMF. That idle current is what detects an open, which is why the code can set with the converter clutch nowhere near being commanded.
Can I diagnose this with a multimeter?
Not reliably. On the 10-speed family the solenoid control is pulse width modulated with both the duty cycle and the frequency changing constantly, so a meter will show voltage at times the application chart says the solenoid is off. Transmission Digest measured the TCC solenoid at 35 to 45 percent duty cycle and 2.6 to 3.5 kHz at light-load cruise on the 10R80. Use a scope for this circuit.
Do I have to program the TCM after replacing the TCC solenoid?
Yes. Every GM 10-speed control solenoid valve is flow tested at the factory and its current-versus-pressure data points are stored in a numbered file marked on the solenoid housing or valve body, hosted on GM's Techline Information System. That data must be programmed into the TCM whenever the transmission assembly, the lower valve body with solenoids, the TCM, or any individual solenoid is replaced. Skipping it makes the module command the wrong current for the hardware installed.
What fluid and how much after this repair?
DEXRON ULV only. GM TechLink's 2025 transmission capacities chart lists 7.7 L / 8.1 qt as the 10L80 fluid change capacity across RPO codes MQB, MQC, MHT, MI2 and MHS. Substituting a heavier low viscosity fluid changes converter clutch apply behavior and can create a shudder complaint on a transmission that is otherwise repaired correctly.
Sources
- General Motors — Service Bulletin 22-NA-015, September 2023, via NHTSA. Backs the 25 to 50 mph steady/light-throttle shudder condition on 2020-2024 Silverado, Sierra, Tahoe, Suburban, Yukon and Escalade models; the instruction to resolve stored DTCs and re-evaluate before proceeding; the Manual L9 test drive to disable Dynamic Fuel Management and GM's statement that DFM vibration should be deemed a normal characteristic; and the GDS graphing criteria separating a TCC solenoid/valve body concern (shudder in D but not L9, throttle under 10 percent, engine torque under 100 Nm, TCC slip speed at or near 0, TCC pressure command at 100 kPa) from TCC solenoid drift and from a torque converter concern (steady TCC pressure control with elevated TCC slip). static.nhtsa.gov (PDF)
- General Motors — Preliminary Information PIP5593A, "10L80 10 Speed Automatic Transmission Restriction Program," via NHTSA. Backs the restriction of 10L80 transmission part numbers 24282946 and 24294934 through the GM Product Quality Center effective 09/20/18, the instruction to contact the PQC at 866-654-7654 when diagnosis has led to transmission assembly replacement, and the note not to clear any DTCs prior to that contact. static.nhtsa.gov (PDF)
- General Motors — GM TechLink "2025 Transmission Capacities & Fluids" reference chart. Backs the DEXRON ULV specification and the 7.7 L / 8.1 qt fluid change capacity for the 10L80 across RPO codes MQB, MQC, MHT, MI2 and MHS. gm-techlink.com (PDF)
- Transmission Digest — "10R80/10L90 10-Speed Solenoid Function," Mike Souza, October 1, 2018. Backs the GM control solenoid valve layout (solenoids 1 through 6 as normally low linear shift solenoids, solenoid 7 as the normally high line pressure control solenoid, solenoid 8 as the normally low variable force TCC solenoid); and solenoid characterization — each solenoid valve flow tested after assembly with increasing then decreasing current applied to the coil winding, the current-versus-pressure data points saved to a numbered file marked on the solenoid valve housing end or the valve body, stored on the Techline Information System, and required to be programmed into the TCM when the transmission assembly, lower control valve body with solenoid valves, TCM, or one or more solenoids is replaced. transmissiondigest.com
- ATRA — GEARS Magazine, "Direct Connection: 10R60, 10R80, and 10R140 Solenoids Make Shifts Happen!" Backs the TCC variable force solenoid operating normally low, with very low output pressure at approximately 50 mA and high output pressure at approximately 850 mA; the key point that control current for the LPC and TCC solenoids does not go to zero when commanded low, an idle current remaining in the circuit to monitor feedback for the module and prevent back-EMF; and the requirement that a replacement solenoid match the band number of the solenoid being replaced. Documented on the Ford side of the shared Ford/GM 10-speed architecture. gearsmagazine.com
- Transmission Digest — "Scope testing the Ford 10R80," Chris Adams (Certified Transmission, ASE Master and L1), February 20, 2023. Backs the observation that Ford and GM moved transmission control back outside the unit; the finding that neither duty cycle nor frequency remains consistent on these PWM solenoid circuits; the measured TCC solenoid behavior of 35 to 45 percent duty cycle at 2.6 kHz to 3.5 kHz during light-load cruise; and the warning that a DVOM shows voltage when the application chart says the solenoid is off, so a scope is required for this testing. Measured on a 2019 F-150 with the 10R80, the Ford twin of the 10L80. transmissiondigest.com
- General Motors — 2020 OBD Group 03A Engine and Transmission Diagnostic Parameters (TCM T87A 10 Speed RWD Summary Tables). Backs the 10-speed TCC control circuit monitors P281B (open, 200K impedance between signal and controller ground, 0.30 s fail out of 0.50 s sample, Type B, 2 trips), P281D (ground short, Type A, 1 trip) and P281E (short to voltage, Type B, 2 trips), the 9.00-32.00 V battery voltage enable, and the absence of P2761 from the 10-speed table. gsi.ext.gm.com (PDF)
- Sonnax — GM 10L80 (Gen. 1) transmission parts listing. Backs the solenoid stabilization clip insert 105740-01K and solenoid stabilization retainer 105740-19K, and the symptom list Sonnax assigns to them: loss of shift solenoid control pressure, poor shift quality, various shift concerns, burnt clutches, TCC apply and release concerns, and damaged valve body casting. sonnax.com