1991 GMC B6 Medium Duty recalls & complaints
Source: NHTSA, updated daily. Last checked 2026-10-19. Recalls apply to specific VINs — run your VIN to confirm.
1 safety recall, most serious first
1. Vehicle Speed Control
What's wrong, in plain English: A vehicle part that may fail. A MANUFACTURING CONDITION IN THE THROTTLE BODY INJECTOR (TBI) UNIT MIGHT OCCUR TO ALLOW THE THROTTLE CAM LEVER TO DISENGAGE FROM THE THROTTLE DRIVE SHAFT.
What could happen: IF THE THROTTLE CAM LEVER DISENGAGES FROM THE THROTTLEDRIVE SHAFT, THE ENGINE COULD GO TO WIDE OPEN THROTTLE WITHOUT PRIOR WARNING.THIS LOSS OF VEHICLE ACCELERATOR CONTROL COULD RESULT IN A VEHICLE CRASH.
The fix: REPLACE THE THROTTLE DRIVE COVER ASSEMBLY.
What to do
- Check whether your car is affected: enter your 17-digit VIN at nhtsa.gov/recalls. A recall covers specific VINs, not every 1991 B6 MEDIUM DUTY.
- Book a repair at any authorized GMC dealer. Quote NHTSA campaign 92V187000.
- The repair is free. By US law, safety recall repairs cost the owner nothing, no matter the car's age or mileage.
- Buying this car used? Ask the seller for proof the recall was completed, or run the VIN yourself before paying.
Official wording from NHTSA
Component: VEHICLE SPEED CONTROL
Summary: A MANUFACTURING CONDITION IN THE THROTTLE BODY INJECTOR (TBI) UNIT MIGHT OCCUR TO ALLOW THE THROTTLE CAM LEVER TO DISENGAGE FROM THE THROTTLE DRIVE SHAFT.
Consequence: IF THE THROTTLE CAM LEVER DISENGAGES FROM THE THROTTLEDRIVE SHAFT, THE ENGINE COULD GO TO WIDE OPEN THROTTLE WITHOUT PRIOR WARNING.THIS LOSS OF VEHICLE ACCELERATOR CONTROL COULD RESULT IN A VEHICLE CRASH.
Remedy: REPLACE THE THROTTLE DRIVE COVER ASSEMBLY.
Notes: SYSTEM: FUEL SYSTEM; THROTTLE LINKAGE.VEHICLE DESCRIPTION: SCHOOL BUSES WITH 6.0 LITER ENGINES.
Useful for owners
Owner complaints filed with NHTSA
Most complained-about parts: Engine (1).
Complaints are unverified reports from owners. A pattern (many complaints about the same part) matters more than any single one.
Read recent complaints (1)
04/09/2003 · Engine
THE VEHICLE EXPERIENCED ENGINE FAILURE FOR THE SECOND TIME. HE STATED THAT THE FIRST TIME WAS 11/99. THE ENGINE HAD 118,000 MILES. HE STATES HE ASKED THE MANUFACTURER FOR ASSISTANCE AND THEY DECLINED BECAUSE OF A TECHNICALITY. HE ALSO STATED THAT THE MANUFACTURE SHOULD REPLACE HIS ENGINE BECAUSE HE SAID THAT WHEN HIS ORIGINAL ENGINE WAS REPLACE THE MECHA…