6T70 Transmission Control Module TCM Replaces 24261875

If your Equinox, Traverse, Acadia, Enclave, Terrain, Malibu, Impala, LaCrosse, SRX or XTS is stuck in a limp gear, has lost communication with the transmission computer, or is throwing control module memory codes such as P0601, P0603 or P0604, the part you are looking for is the 6T70 transmission control module. On this transaxle that module is not a box under the hood. GM builds it into the control solenoid valve assembly that sits on the valve body inside the case, and the whole assembly is commonly called the TEHCM. This remanufactured unit replaces GM 24261875, 24275870, 24041871, 24264346 and 24275868 on the 6T70, 6T75 and 6T80.

What the TCM does in a 6T70

The 6T70 family shifts clutch to clutch, with no conventional shift valves doing the timing. Every shift is a computer decision. ATRA's 6T70 seminar describes the assembly as a Bosch-built 32-bit TCM carrying two on/off shift solenoids and six variable bleed solenoids (PCS1 through PCS5 plus the TCC solenoid). The module reads input and output speed, fluid temperature and range, then commands each pressure control solenoid to fill one clutch while it releases another. It also controls line pressure and converter clutch apply, and it stores the learned fill values for each clutch.

Because the electronics live inside the transaxle, heat is the enemy. GM uses a spring-loaded bracket to press the module against a heat sink on the valve body, and ATRA warns that leaving that bracket out causes TCM thermal shutdown.

Symptoms of a failing 6T70 TCM

• Transmission locked in a fail-safe gear with the converter clutch off and firm, high-pressure shifts
• P0601, P0603, P0604 or P062F stored in the TCM (internal memory faults)
• P0602, control module not programmed, after a repair or battery event
• No communication with the TCM on a scan tool once wiring, power and grounds check good
• Intermittent faults that come and go with transmission temperature
• On Gen 1 units, pressure switch codes such as P0752, P0872, P0877 or P0989, since the switches are part of this assembly

How to confirm before you buy

GM's diagnostic for the memory codes is clear. With a scan tool, first check whether P0602 is set. If it is, program the TCM; only if the code returns after programming, or P0601, P0603, P0604 or P062F set again, is the control solenoid valve assembly replaced. When any of these Type A codes are active, the TCM limits the transaxle to Reverse and 5th, commands maximum line pressure and freezes adapts, so a car that suddenly will only pull away in a high gear fits this pattern.

Rule out the mechanical failures first. A broken 3-5-R wave plate causes no Reverse, 3rd or 5th with P0776, and that is a hard-parts repair, not a computer. Our 6T70 common problems and fixes guide separates the two, and the 6T70 Equinox shift problems guide covers harsh shifts that turn out to be unlearned adapts.

Fitment

Listed applications: Chevrolet Equinox 3.6L 2008-2017, Traverse 3.6L 2009-2017, Impala 3.5L and 3.9L 2011, Malibu 2.0L 2013-2015; Buick Enclave 3.6L 2008-2017, Allure 3.6L 2014-2015, LaCrosse 3.6L 2014-2016, Regal 2.0L 2014-2017; GMC Acadia 3.6L 2007-2019, Terrain 3.6L 2010-2017; Cadillac SRX 3.0L and 3.6L 2013-2016, XTS 3.6L 2013-2019; Pontiac G6 3.6L 2007-2009, Torrent 3.6L 2008-2009; Saturn Aura 3.6L 2007-2009, Outlook 3.6L 2007-2009 and Vue 2.4L and 3.5L 2008-2010. GM revised this assembly between early and late units and again with the 2013 Gen 2 controls update, so match the GM number on the label of your original assembly to the list above, or send your year and VIN before ordering. All 6T70 parts are on the 6T70/6T75 collection page.

Install notes

• Drain the fluid and remove the case side cover to reach the assembly. GM's side cover gasket is not reusable, and ATRA notes the studded side cover bolts must be re-torqued whenever the cooler lines are removed.
• Reinstall the spring-loaded heat sink bracket. Skipping it causes thermal shutdown.
• The module must be programmed to the vehicle with GM's Service Programming System or an equivalent tool, then a transmission adaptation reset performed. It will not run the transaxle correctly unprogrammed.
• After programming, run Service Fast Learn Adapts with the scan tool, then drive so the adapts finish learning.
• Refill with DEXRON VI only and set the level with fluid at 180 to 200 F. A new 6T70/6T75 filter and gasket kit belongs in the job if the unit is coming apart.
• If your valve body itself is worn, a matched 6T70 valve body is the other half of this assembly.

Is the 6T70 TCM a separate module I can swap without opening the transmission?

No. On the 6T70, 6T75 and 6T80 the TCM is built into the control solenoid valve assembly inside the transaxle. GM does not service it separately, and you reach it by removing the case side cover.

Does this TCM need programming?

Yes. GM requires a replacement TCM to be programmed to the vehicle with its Service Programming System, followed by a transmission adaptation reset. Plan on a scan tool capable of GM programming or a shop visit.

My car only moves in a high gear and the converter will not lock. Is it the TCM?

It can be. When P0601, P0603, P0604 or P062F set, the TCM limits the transaxle to Reverse and 5th and shuts the converter clutch off. Scan the TCM first. If only P0602 is present, programming alone may fix it.

Which vehicles does it fit?

6T70, 6T75 and 6T80 vehicles from 2007 to 2019, including the Equinox, Traverse, Acadia, Enclave, Terrain, SRX, XTS, LaCrosse, Regal, Malibu 2.0L, G6, Outlook, Aura and Vue. Match the GM number on your old assembly or send your year and VIN.

What fluid does it need after install?

DEXRON VI only. Check the level on the dipstick at 180 to 200 F fluid temperature, on level ground with the engine idling.

• 6T70 Common Problems and Fixes
• 6T70 Equinox Shift Problems: Diagnosis and Fix
• 6T70 Acadia Shift Problems: Diagnosis and Fix
• 6T70 Acadia Common Problems and Fixes