Transmission programming modules: When to reprogram and when to replace

Transmission programming modules: When to reprogram and when to replace

Programming modules have been an essential aspect of the complete repair and service experience (Figure 1) within the automotive industry for quite some time now. Not providing this service shortchanges both the shop and the customer; yes, the repair has been performed, but the vehicle is still not working as well as it could be. Aside from fine-tuning the work performed, programming the latest calibration updates into the vehicle often resolves issues beyond the specific repair completed. When it does, it’s always nice to hear a customer say, “My car never ran so well.”

Figure 1.

When it comes to programming modules that control automotive transmissions, there is a difference between reprogramming and replacing a program, and it is all a matter of clicking the correct button (Figure 2).

Technically Speaking June Figure 3
Figure 2.

To clarify, to “Reprogram” means to update the existing calibration with the latest software available. One such example of needing to “Reprogram” is if a vehicle comes to a shop exhibiting symptoms and/or codes that a TSB is addressing by updating the calibration to the latest software. To “Replace and Program” is to write a completely new and updated calibration. This is needed when fully replacing a transmission with either a new, remanufactured or used transmission.

When it comes to a TEHCM used in a GM 6L80 transmission, for instance, we have discovered that it is not overly sensitive to the VIN. Nor does it seem to be sensitive to GM’s Global Diagnostic System (GDS). Let me explain. This new security protocol was introduced here in the U.S. in 2010 and by 2014 was being used in all platforms. This Global Diagnostic System is often referred to as GM’s “Global A” system. The Body Control Module is the controlling module for the GDS system. It sends an “Identifier” signal over the serial data lines to which GDS compliant modules must respond by comparing module identification to the identification originally programmed into the BCM. If the BCM identifier is not recognized or receives an incorrect identifier from one of the other GDS compliant modules, it will respond by preventing the vehicle from starting. 

Read more stories from our Technically Speaking column series here.

With this brief understanding of what GDS is, the TEHCM used in a 6L80 transmission has not shown itself to be sensitive to this system. We have seen, on rare occasions, code U0101 setting for a Loss of Communication to the TCM, causing the vehicle to not start due to a variety of reasons unrelated to the GDS. What does occur on a regular basis is that when a previously used module is installed, an error message occurs indicating that there is no communication to the module along with a VIN mismatch. In these cases, the PID display remains functional, and the vehicle will start. 

To remedy a used TEHCM that has a program installed into it associated with a different VIN, the option to “Replace and Reprogram” must be selected in the programming process, NOT just “Reprogram.”  This will allow the correct program associated with the VIN of the vehicle to overwrite the existing program and to install the latest updates, completing an optimum repair.

To be a bit more specific, a shop may be tempted to not perform any programming updates when a used TEHCM is installed from a different vehicle, and it seems to drive well. This is not the best way to send the vehicle out, as in most cases the program is not fitted for the vehicle it is in. Additionally, the latest updates are also not installed. This allows for pesky and annoying problems to lurk within the program that could result in repeated transmission failure; or, at least, continuous complaints from the customer about how the transmission doesn’t seem to shift right.   

One of the more common issues that arises when swapping 6L80 TEHCMs is due to a running change made sometime between 2013 to 2014. New instrument clusters now provide Transmission Fluid Temperature data. This means the TEHCM is fitted with a program to provide both Transmission Temp for the TCM and for the Instrument Cluster. A mismatch in TEHCMs will usually show Trans Temp at -40°F. Replacing and reprogramming will resolve this as well. 

Finally, unrelated to this, is the code that indicates a failure of the TCM itself. It is the code for an Internal TCM Temperature Overheat. This code means you need another TEHCM. It literally means it’s toast!

You May Also Like

Ford 8F24 mechanical diode failure

Mechanical diode failure in automatic transmissions is not uncommon. As far back as the AODE/4R70 shops have seen this type of failure. In April 2022 an article was published in Transmission Digest called, “The ins and outs of the Hydraulic Selectable One-Way Clutch (SOWC).” This article provided photos of the type of damage this style

Tech-Speak-April-Figure-1-1400

Mechanical diode failure in automatic transmissions is not uncommon. As far back as the AODE/4R70 shops have seen this type of failure. In April 2022 an article was published in Transmission Digest called, “The ins and outs of the Hydraulic Selectable One-Way Clutch (SOWC).” This article provided photos of the type of damage this style diode is susceptible to in 9T50 and 8F35 transmissions.

Ford 8F35 maintenance tips: Planetary failure and no-pressure conditions

Our shop has had several vehicles come in with the Ford 8F35 transmission having planetary failure. Apparently, there was a run where the pinion needle bearings had a hardness problem (see Figure 1). Related Articles – Back with force: ATSG is back in full swing to educate the transmission industry – Don’t fear customer complaints about

Figure 12.
Don’t fear customer complaints about CVTs

Continuously Variable Transmissions, or CVTs, are more common than you think. Audi, Subaru, Nissan, Ford, GM and many other automakers use CVT transmissions in cars and SUVs. There is no way to avoid them. Chances are there is one in your shop right now. Related Articles – Powertrain industry directory and buyer’s guide 2024 –

CVT-Transmission-2
Shift Pointers: A Chrysler 300 no-shift complaint

The case study has to do with a 2009 Chrysler 300 C 5.7L Nag1 RWD with 71,923 miles on it (see Figure 1, above). Related Articles – Shift of the shaft: Diagnosing Chrysler 48RE manual shaft issues – Sometimes, a diagnostic code is all you need – 10L80 and 10R80 pump gear differences It is

A guide to common GM, Ford and Nissan programming issues

One of the most common complaints I hear from shops when trying to install a new GM TCM is, “The module will not communicate.” While that might be partially true, by design they won’t communicate until they are programmed. If programming fails, there will be an “E” code set which will help you get to

Other Posts

Schaeffler releases TorCon 6L80 torque converter

Schaeffler announced the debut of the LuK TorCon 6L80 torque converter, which the company notes is all-new and not remanufactured. Related Articles – American Powertrain adds GearStar automatic transmissions for Ford, Chevy, Mopar – PRT launches 59 new complete strut assemblies – Raybestos adds new Toyota UA80 / UB80 converter clutch plates The TorCon 6L80 is

Going the extra mile: Proving your transmission repair suspicions

A 2003 Honda Pilot with a five-speed three-shaft transmission came into our shop with a customer concern that the vehicle had no power, and the “D” light was flashing. I first did a scan for codes to see what it came up with, and the scan tool returned four DTCs: P1298 (ELD voltage high), P0135 (H02S

RRfeature-1400
Diagnosing Ford 10R60, 10R80 and 10R140 series speed sensor issues

Ford 10-speed 10R series transmissions utilize four two-wire, Hall-effect sensors — TSS, ISSA, ISSB and OSS — for providing speed signals to PCM or TCM. They are supplied nine volts by a PCM or TCM and assist in the control of clutch apply/release timing that is used in determining shift quality, including TCC. Related Articles

Jatco JF613E transmission quick reference material

For those working on the Jatco JR613E transmission, a widespread transmission with plenty of applications, the following should be a helpful guide. Related Articles – Outgrowing the walls: The story of EVT Transmission Parts – Spotting different 68RFE designs through the years to avoid issues – Valve body and component suppliers: A comprehensive list Domestic