Summary
The GMC Sonoma has 16 recalls covering the 1991-2003 production run, with the most serious being a transmission defect on 1996 models where internal parts can cause the transmission to seize and lock the rear wheels while driving, resulting in sudden loss of control.
The 1996 model year carries several additional issues. A front brake line can wear against the engine oil pan until it ruptures during braking, causing brake fluid loss and significantly longer stopping distances. The 1996 windshield mounting is also affected, where paint peeling on the windshield flange weakens the adhesive bond and can allow the windshield to separate in a crash. There is also a fuel vapor leak from fuel injectors on some 1996 models, and an evaporative emissions compliance issue associated with it.
The 2000 model year has two brake-related issues: a brake pipe fitting that can lose its seal and leak fluid, reducing braking effectiveness, and an anti-lock brake motor spring clip that can shift out of position over time, eventually disabling the anti-lock system and rear brake proportioning entirely. The 2000 model also has a vehicle certification label showing a payload capacity higher than the validated maximum, which can cause unexpected handling and stopping behavior if the vehicle is loaded to that incorrect figure.
The 1998 model year has an engine wiring harness clip that can melt and drip onto the exhaust manifold, where the material can ignite and spread to nearby components, causing an engine fire.
Going back to 1994, certain vehicles have front seatbelt webbing that can tear apart in a frontal collision, leaving occupants unrestrained if secondary impacts or a rollover follows. The 1994 model also has a fuel tank filler pipe that does not meet fuel system integrity standards and can leak fuel in excess of regulatory limits.
The 1991 model has an ABS-related issue specific to four-wheel drive versions: a sensor switch can incorrectly tell the anti-lock system the vehicle is in four-wheel drive while it is actually in two-wheel drive, causing longer stopping distances during hard braking.
The 2003 model has an airbag caution label with an incorrect statement about child seat placement, though the owner's manual for those vehicles contains accurate information.
