• Solenoid electrical circuit faults
  • Solenoid performance codes
  • Gear ratio codes
  • Poor shift quality
  • TCC codes
  • Internal memory codes
  • Temperature sensor codes


Internal component failure or circuit faults within the TEHCM creates no or poor communication with the onboard TCM, resulting in poor shift quality and numerous diagnostic trouble codes.


Install a remanufactured Sonnax TEHCM that has been thoroughly cleaned and updated with new components where necessary and electro-hydraulically tested for OE performance in a simulated drive test.

6L80, 6L90

Remanufactured TEHCM
Part No. GM6L-TEHCM-C5

Typically fits Cadillac 2010–2011; Chevrolet 2010–2013; GMC 2010–2011

OE Part No. 24251029, 24251412, 24254908, 24256051, 24256124, 24257141, 24258304, 24275874

View Instructions Find a Distributor

The GM 6L80 and 6L90 TEHCM houses the transmission control module (TCM), or computer. The eight solenoids are connected to the TCM via a lead frame, all of which are over-molded in the plastic housing and not accessible or serviceable separately. Component fails and circuit faults in the TEHCM are common, and result in drivability complaints and trouble codes which can only be remedied with a replacement unit.

Sonnax remanufactured TEHCM GM6L-TEHCM-C5 delivers durable, reliable OE performance at a significant savings over an OE replacement. Each unit goes through a rigorous cleaning and inspection process where all failed components are replaced. Electro-hydraulic testing in a simulated drive test ensures full functional performance consistent with a new OE TEHCM. A vehicle VIN remains on the Sonnax remanufactured TEHCM, and will be overwritten by the transmission shop technician with the new vehicle VIN during the reprogramming process. After installation, this remanufactured TEHCM must be reprogrammed on the vehicle using a J2534 device in order to function correctly.

The fully tested TEHCM is serialized, and the test data stored and packaged in mylar bag with a protective connector cover to prevent inadvertent static discharge issues during the shipping, handling and receiving processes.

  • Ultrasonically cleaned and thorough flushing of solenoids to remove all dirt and debris — no matter how hidden
  • New pressure switches installed
  • New filter plate/screen installed
  • Fully electro-hydraulically tested to comply with OE performance
  • Must be reprogrammed prior to installation using a J2534 device for proper function

Sonnax TEHCMs have "Sonnax" lasered on the TCM cover for quality assurance purposes. See web image for reference.

  • 6L80, 6L90 Remanufactured TEHCM GM6L-TEHCM-C5
  • 6L80, 6L90 Remanufactured TEHCM GM6L-TEHCM-C5 details


6L80, 6L90 Remanufactured TEHCMs for Top-Quality, Affordable Repairs

Our partnership with Sonnax produces an enhanced solution for many of today’s complex transmission, torque converter and general driveline issues that trickles directly to our customers. For a quick example, the Sonnax 6L80/90 TECHMs, and the peace of mind and value added for our customers. It proves that Sonnax has their ear to the ground.

B. Cook
Purchasing Manager, Whatever It Takes Transmission Parts

The remanufactured TEHCMs for 6L80 and 6L90 are another example of [Sonnax] quality and expertise. We sell and use them exclusively in our own rebuilds, saving our customers hundreds of dollars each time compared to a brand-new TEHCM. We highly recommend everyone try them.

D. Apice
Owner/Operator, Viper Transmission Parts