10L80 Identification Guide: RPO Codes, Generations and Valve Body ID

"It's a 10L80" is not an identification. It is a family name. Between 2017 and today that name has covered three different valve body architectures, two different shifter systems, an optional stop-start feature, and a safety recall that applies to some of those units and not others. Order a part off the family name alone and you are guessing.

This is the order I work in on a unit I have not seen before: RPO first, family second, valve body generation third, then the electronics. Every one of those steps is verifiable in a few minutes, and each one eliminates a whole category of wrong parts.

Recommended 10L80 parts

Once the RPO and the valve body generation are nailed down, these are the parts the job usually needs. Secure checkout, ships from the USA.

10L80 Transmission Valve Body Solenoid Kit, 10-Piece

$527.99View part

10L60/10L80/10L90 Transmission Filter and Pan Gasket Kit

$30.99View part

10L80 Friction Clutch Module Kit 2017-Up, 35955KIT

$169.99View part

Step 1: pull the RPO code, not the model year

ATRA's own guidance on this family is that the easiest way to identify the unit is the RPO code, read off the QR label on the driver's door B pillar with a QR reader app on a phone. That label is the factory build record for that VIN, and it beats anything you can see with the pan still on.

The useful part is that GM publishes which RPOs are 10L80s. Service Bulletin 22-NA-015 covers shake and shudder complaints on 2020-2024 Silverado 1500, Sierra 1500, Tahoe, Suburban, Yukon and Escalade models with the L84 and L87 engines, and its transmission RPO field lists MQB, MQC, MHS, MHO, MHT and MI2. A January 2023 revision of that same bulletin added M12, MHO and MHT to the RPO section, which tells you the list grew as applications did. GM's 2025 Transmission Capacities and Fluids chart carries more 10L80 codes on the car and crossover side, including MHU.

Two things to take from that. First, a code like MQB is a specific build of 10L80, not a generic label, which is exactly why bulletins scope themselves by RPO instead of by model name. Second, no single bulletin's RPO list is the complete set of 10L80 codes, because each bulletin only lists the codes relevant to the vehicles it covers. Use the door label to identify your unit; use the bulletin list to confirm the unit belongs in that bulletin.

Step 2: separate the family members by fluid and capacity

If you are staring at a loose unit with no label, fluid volume is a fast sanity check before you go any further. GM's 2025 capacities chart is the reference:

Correction and update, September 19, 2026: an earlier version of this table put the 10L90 RPO MHX on the XT6 and the 10L60 codes on the XT4. GM's 2025 chart actually lists MHX under the CT5, MQA under the CT4 and MQ2 under the CT5; the XT4 and XT6 use 9-speed front-drive units. The same chart gives the 10L60, 10L80 and 10L90 an identical 7.7 L fluid change, so volume cannot separate those three. What GM rates differently is torque: the Chevrolet Performance Supermatic 10L90 instructions put the 10L90 at 650 lb-ft and list the overhaul fill at 10.95 L (11.6 qt), with 12.52 L (13.23 qt) for the complete system including the cooler. For the full 10L90 walkthrough, see our 10L90 identification guide.

The capacity gap between a 10L80 and a 10L1000 is the cleanest separator in the family. If someone handed you a unit and a drain pan and you caught fourteen quarts, you are not holding a 10L80. Note also that every row in this family calls for DEXRON ULV. Any listing that tells you a 10L80 takes DEXRON VI is quoting an outdated or careless source, and that mistake is common enough online that it doubles as a test of whether a page is worth reading.

Step 3: identify the valve body generation, because that is what actually changed

This is the step most people skip, and it is the one that decides whether the part on the shelf will work. There are three generations of 10L60/10L80/10L90 valve body.

Generation 1 (2017-2019)

The original architecture. Gen 1 units use latch valves in the clutch control circuits and a smaller separator plate. This is the generation whose TCC regulator valve bore wear is the classic cause of lockup shudder: wear around that bore cuts converter apply flow, release flow and cooler flow all at once, while boost sleeve wear bleeds off signal oil and kills lockup outright.

Generation 2 (2019 and later)

GM changed the clutch application, deleted the latch valves, and added checkballs in line with the feed limit valves to handle clutch regulation instead. The separator plate got larger. The lower casting is still there with the default disable solenoid mounted in it, and the feed limit high valve is present along with boost balls for the C and F clutches. Gen 2 is the generation that carries the recall exposure covered below.

Generation 3 (June 19, 2025 and later, as a service part)

The newest valve body exists under two part numbers: 24071206 for 3.0L diesel applications and 24071207 for 5.3L and 6.2L gas in GM trucks. Both fit ETRS models with electronic park control only. The fastest way to spot one is the solenoid layout: the TCC solenoid moved to the case side of the valve body, the lower casting is gone entirely, and the default disable solenoid now mounts to the lower cover plate. Inside, the pressure regulator valve was redesigned toward the 10L1000 design, there is now only a single feed limit valve (the feed limit high valve train is gone), and the C and F clutch boost balls were removed. The clutch control valves are labeled A through F, cast right into the lower valve body, which is a genuinely useful change on the bench.

The Gen 3 valve body was redesigned specifically to prevent the wheel lockup condition behind the recalls, and it will back-service earlier vehicles even though it does not look like what came out. That is the trap: a correct Gen 3 replacement for a Gen 2 truck will look wrong to a tech expecting a visual match, and the instinct is to send it back. Verify fitment by VIN before you install it, every time.

Step 4: ETRS or cable, and does it have stop-start

Two build options split the family further, and both are visible without a teardown. The unit either has ETRS (Electronic Transmission Range Select, shift-by-wire, with electronic park control) or a conventional cable-operated shifter. Separately, some applications carry the Auto Start Stop Feature. ETRS is not cosmetic for parts purposes: the Gen 3 valve body part numbers above are ETRS-only, so a cable-shift truck cannot take one.

Step 5: is this unit in the recall?

GM Safety Recalls N242480630 and N242454440 cover the 10L1000 and the Gen 2 10L60, 10L80 and 10L90 in 2019-and-later cars, SUVs and trucks. The root cause is wear in the feed limit low valve, which gradually bleeds off the control pressure feeding the default disable solenoid. What the customer feels is a momentary rear wheel lock-up at higher speed, sometimes with an unexpected downshift to 2nd gear. P0747, E clutch engaged when it should be disengaged, is the code that commonly turns up with it.

Notice what that means for identification. A 2018 Gen 1 10L80 sits outside this recall. A 2021 Gen 2 10L80 sits inside it. Same family name, an entirely different conversation with the customer, and the only thing separating them is the generation you identified in Step 3.

Step 6: confirm it electronically on the bench

Solenoid identification and the data file

The 10L uses eight transmission control solenoid valves, and all eight are pressure-regulating, not simple on/off. Each one is flow-tested after assembly with increasing and then decreasing current applied to 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 file lives on GM's Techline Information System. It has to be programmed into the TCM whenever you replace the transmission assembly, the lower control valve body with solenoids, the TCM, or one or more solenoids. It is the same idea as solenoid characterization on the 8L90.

ATRA's guidance adds a related warning worth knowing before you quote the job: the Linear Pintle solenoids are not available separately. If one is sticking, or if the LPC accumulator bore or a Linear Pintle bore is worn, you are ordering a valve body and doing PUN or MCVM programming, not swapping a solenoid. Weak or broken solenoid retainer clips belong on the same inspection list.

The four speed sensors

There are four internally mounted two-wire Hall-effect speed sensors, all fed a 9-volt supply from the TCM: input speed sensor (ISS, also called turbine speed sensor), intermediate speed sensor 1, intermediate speed sensor 2, and output speed sensor. Three of them are conventional, with a magnetic pickup in the tip reading a steel reluctor ring; intermediate speed sensor 1 reads a 50-tooth ring welded to the reaction planet carrier internal gear and reverse brake clutch hub.

The input speed sensor is the odd one out and the one that catches people. It has no magnet in the tip. Instead it reads a reluctor ring of 40 evenly spaced magnets bonded in rubber, riveted to the input planet carrier and read straight through the wall of a non-ferrous transfer shell. That difference shows up on the meter: the input speed sensor measures approximately 346.7 kilohm, while the other three measure roughly 4.88 milliohm. If you are checking a harness and one sensor reads nothing like its neighbors, that is the expected result, not a fault. The connectors are keyed with the alignment tab in a different location per color, and where two connectors share a color they sit far enough apart on the case to prevent a swap.

What the ID actually buys you on a shudder complaint

Here is the payoff, using the shudder case straight out of 22-NA-015. On a verified 25-50 mph shudder, GM has you record a GDS session and graph three things: engine torque, engine speed and transmission ISS. If the shudder is present in Drive but not in Manual L9, throttle is under 10 percent, engine torque is under 100 Nm, TCC slip speed is zero or near zero, and the TCC pressure command sits at 100 kPa, the valve body is the repair. If instead TCC slip is elevated while engine torque and throttle angle stay steady and engine RPM rises and falls against a steady ISS, the converter is the repair.

GM attaches a note to that second case worth repeating to anyone who reaches for a converter first: warranty claim review shows that when the converter is replaced for shudder, the vehicle often comes back for additional engine or transmission work, because in most cases the converter was not the cause. Also, run the test in manual 9th so Dynamic Fuel Management is disabled, or you will chase a normal DFM vibration as a transmission fault.

One more that has nothing to do with the transmission and everything to do with wasted hours: a chassis code C0267, low brake fluid level, will cause no upshifts in Tow Haul mode on this family. Nothing in the OEM procedure points you there. Scan the whole vehicle before you drop a pan.

The short version to write on the job ticket

• RPO code from the QR label on the driver's door B pillar. MQB, MQC, MHS, MHO, MHT, MI2, M12 and MHU are all 10L80 codes GM has published.
• Generation. Latch valves and a small plate equals Gen 1 (2017-2019). Checkballs at the feed limit valves and a larger plate equals Gen 2 (2019 and later). TCC solenoid on the case side with no lower casting equals the Gen 3 service valve body (24071206 diesel, 24071207 gas, ETRS only).
• Shifter. ETRS with electronic park, or cable. This gates the Gen 3 valve body.
• Recall exposure. Gen 2 and 10L1000 only, under N242480630 and N242454440. Feed limit low valve, watch for P0747.
• Solenoid data file read off the solenoid housing end or the valve body, and programmed into the TCM after any solenoid, valve body, TCM or transmission replacement.
• Fluid: DEXRON ULV, 7.7 L / 8.1 qt for a pan and filter service.

Related guides

• 10L80 vs 10L90: Differences, Interchange and Which Is Stronger
• GM 10L80 Problems and the Valve Body Recall
• 10L80 Valve Body Symptoms
• 10L80 Fluid Type and Capacity: DEXRON ULV and 8.1 Quarts
• 10L80 Torque Converter Shudder