Automatic Emergency Braking problems of the 2021 GMC Sierra 1500

One problem related to automatic emergency braking has been reported for the 2021 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2021 GMC Sierra 1500 based on all problems reported for the 2021 Sierra 1500.

1 Automatic Emergency Braking problem

Failure Date: 04/22/2026

2021 GMC sierra at4, VIN [xxx] , NHTSA campaign 25v-274, gm case xxx. Brake pad monitor failed at 128,923 miles -- 24 miles after leaving penske Chevrolet (released at 128,899, ro xxx, 04/17/2026). Brakes became spongy immediately following service. Monitor disabled entirely to stop recurring red service system alert. Root cause is a burnt fuse block ground fault confirmed in writing by two gm-authorized dealers. Ray skillman (ro xxx, 06/05/2025) documented the fault then deleted labor operation 14buz engine electrical from the recall repair work order. Penske documented verbatim: "all of these other faults share this same ground circuit. " the recall repair at ray skillman used a remanufactured short block instead of a complete engine per n252494002. The original seized-engine oil pan has never been replaced across three dealerships and 128,000 miles. Gm's own part 573 filing states this defect "increases the risk of a crash. " I drove 300 miles on an interstate on 04/22/2026 with active brake warning and no loaner because gm executive resolution refused to authorize one. Three gm dealers have inspected this vehicle. Gm executive resolution team [xxx] ) has not returned calls or emails and has not confirmed in writing this vehicle is safe to operate. Onstar issued a critical alert for p0617 on 04/15/2026. Zero brake faults existed in the 13 months prior to the penske visit. This is a direct continuation of unresolved electrical damage from a botched federal safety recall repair at 384 days and counting. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).


Other Forward Collision Avoidance related problems of the 2021 GMC Sierra 1500

Warnings problems
2
Adaptive Cruise Control problems
2
Automatic Emergency Braking problems
1


Sierra 1500 Service Bulletins
Sierra 1500 Safety Recalls
Sierra 1500 Defect Investigations