Repairing GM TCM Module 24257038 for Allison transmission.

Repairing GM TCM Module 24257038 for Allison transmission.
A common issue with these modules are heat related. When the module is cold, the transmission shifts properly, but as soon as it gets hot, it stops shifting and throws an error code.
It is believed this is because of cracking solder balls on the BGA microcontroller.
Currently, this module is och national backorder and this is due to a supplyer issue of core parts inside the unit.
Desoldering the microcontroller from the pcb presents multiple issues. First issue is the PCB glued to the heatsink. PCB is also wire bonded to the connector making it totally impossible to separate the pcb from the heatsink, making desoldering hard. In addition, the pcb has been vacuum immersed in conformal coating epoxy, gluing the chip to the board...
On the underside of the pcb are multiple memory chips located. If to much heat is applied, those chips will desolder and fail ruining the module.
In order to resolder the microcontroller without destroying the nearby parts, low temp solder balls are used. They are comprised of bismuth and tin, lowering the melting temperature to approx 180C, wich leaves more than 50C in margin to the other solder used in the module.
----------------------------
Grufman Bil är en fristående bilverkstad och reservdelsåterförsäljare för USA-Ford, Chrysler, Tesla och GM. Välkommen!
www.grufmanbil.se

Gillar du vad vi gör?
Stötta oss genom att använda vår rekommendationslänk hos Tesla nästa gång du beställer en ny Tesla.
https://ts.la/grufmanbilab10977