GMC C6500 complaints by model year
1999 GMC C6500 recalls (4)
Engine and engine cooling › Engine › Gasoline
Certain medium duty c-series and b7 school bus chassis equipped with a 7.4 liter gas engine and an impco lpg conversion kit. Some of these vehicles May have engine backfires with sufficient force to damage the engine air intake system and the air cleaner filter element.
Remedy: Dealers will install a redesigned mixer bonnet and air cleaner housing cover, selective upgrades in various connections related to the air induction system, and if needed, a new air cleaner filter.
Service brakes, air › Antilock
Vehicle description: school buses, medium duty trucks and tractors built with bendix air ABS with an ec-17 1030r electronic control unit (ECU), there have been reports of unwanted ABS activation at low speeds caused by 1) chafed ABS wheel speed sensor wires on rotating parts or 2) a damaged component at the wheel end that…
Remedy: Dealers will replace the ABS ECU.
Power train › Automatic transmission
Vehicle description: medium duty trucks. The transmission fluid could leak from a heat degraded transmission fluid cooler hose onto the exhaust system on the passenger's side of the vehicle.
Remedy: Dealers will install a new transmission fluid cooler inlet hose and outlet hose designed with a heat sleeve and ensure adequate clearance to the exhaust system take-down pipe.
Power train › Automatic transmission
Vehicle description: medium duty conventional cab trucks and school bus chassis equipped with an automatic transmission, have transmission shift cable end rods that have not been crimped to the proper specification.
Remedy: Dealers will install a new shift cable.
Frequently asked questions
How many recalls does the 1999 GMC C6500 have?
There are 4 recalls for the 1999 GMC C6500, the most recent from November 4, 2002 (gasoline). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.