DTC U0121 x 4. "4 modules not communicating to EBCM"

DJ44
Tue, 02 May 2023 15:54:49 +0000
Maintenance/Repairs

2013 GMC Terrain. Recap: BRAKE, ABS, TRAC lights on. “Service power steering message”, collision and lane depart not working, multiple new fully-charges and tested-good batteries die within 48 hours with car off. Cause of drain was ABS module fuse. $200 spent at dealer for diagnostic. Came back with DTC U0121. Want $2000 to replace module #22754644 and valve kit #23156466 said to “start here first”. Am I just totally screwed or could it still be something cheaper and easier to fix and are they just telling me the most expensive thing possible? Car is in brand-new condition. Everything is spotless and immaculate. You could park it inside a showroom with the hood open and nobody would know the difference. Has only 16k miles on it but is out of warranty.

43 posts - 11 participants