Most common 1999 GMC Sonoma problems
Share of the 57 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
GMC Sonoma complaints by model year
Best Sonoma years: 2003, 1999, 2002. Years to avoid: 1995, 1996, 1998. Compare all years →
What 1999 GMC Sonoma owners say
Brakes
During a panic stop the brake system light came on and the brakes felt soft but still worked. During the drive the brakes became very weak. When I checked the brake fluid it was empty. I refilled it and started checking for leaks. I found that both the front and rear brake lines we fractured because of the pressure during the panic stop causing the rusted lines to burst. This seems to be a known ( but not reported) problem for this truck in the northern area..
1) boyfriend driving, pulled up to intersection, truck stalled, restarted, died, noticed smoke, opened hood, fire near battery and antifreeze container, put out with snow, vehicle towed to dealership, contacted GM, told a rep would contact me within 24-48 hours, that was a week ago, no call, vehicle just sits!! 2) ABS light on, told by dealership to make appointment, not a big deal. When light was on that was true, but light didn't always come on and it was like a brick was behind the brake. Had to slam on it! Not good on these winter roads. Dealership did replace left wheel speed sensor harness. 3) noticed oil leaking slightly, dealer replaced engine oil cooler lines 4) stuck in 4x4. Dealer replaced trasnfer case encoder. Said common problem in cold weather. However, only had one cold snap, vehicle is brand new, thought this was unusual. 5) third door handle broke when opening. …
Transmission & drivetrain
Dealer where vehicle was towed for repairs says the automatic transmission must be pulled and disassembled to determine what is broken and the factory will not provide warranty relief since the truck is over 4 years old even though the vehicle has only 36,489 miles. Original warranty was 3 years or 36,000 miles which ever comes first. Vehicle has been serviced by dealer since purchase. The truck gave a high screeching noise and loss of power in the transmission, forward drive gear. I pulled off the fairfax county parkway in herndon and pulled into a parking lot. Next day tried to back up truck and transmission gave screeching noise and vehicle would not move. If vehicle is 2, 3 or 4 years old but only has 36,489 miles why can't GMC provide relief for a vehicle defect in the transmission which is safety related due to loss of power and maneuver ability when it occurred? …
While parked in reverse position with the clutch assembly, the vehicle rolled back unexpectedly which May have caused injuries. Manufacturer said that it stated I the owner's manual to use the emergancy parking braking only when in parked/ reverse positions, but never stated the consenquences of rolling back. Also, vehicle May roll while parked in any gears. Please provide further information and VIN#.
Seats
The driver's seat adjust failed. No pressure--could be put on the seat without it moving to the full back position. The dealer initially replaced this in mar 05 after me and dealer speaking with GMC customer satisfaction. GMC reimbursed me for costs. 15 months [!!] later, it failed again. The dealer had only seen this issue twice, both times with my car. GMC initially declined to pay for the repair. Then, after discussion with me, they offered to pay for it with me understanding that they had no liability and would not pay for any future repairs or would offer me $500 certificate discount on a new GMC truck. When I mentioned the safety issue potential, they wanted me to understand that if I accepted the money, I would have no standing in future problems of the same nature. I decline. I am concerned about the safety potential of this. They have twice corrected the symptoms. …
Both driver and passenger seat recline handles have completely leaving both seats incapable of reclining. Unfortunately, leaving the occupants vulnerable if an accident were to occur. Drivers side broke twice. 1st time repaired under waranty. Drivers side broke after waranty had expired. Passangers side same after warnty expired. Neather replaced at this time.
1999 GMC Sonoma engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 2.2L 4-cyl | 5-speed manual | RWD | 20 / 26 / 23 |
| 2.2L 4-cyl | 4-speed automatic | RWD | 17 / 24 / 19 |
| 4.3L 6-cyl | 5-speed manual | RWD | 15 / 21 / 18 |
| 4.3L 6-cyl | 4-speed automatic | RWD | 15 / 20 / 17 |
| 4.3L 6-cyl | 5-speed manual | 4WD/AWD | 15 / 20 / 17 |
| 4.3L 6-cyl | 4-speed automatic | 4WD/AWD | 14 / 19 / 16 |
EPA ratings. Class: Small pickup.
Frequently asked questions
Is the 1999 GMC Sonoma a good car?
Based on 57 owner complaints filed with NHTSA, the 1999 Sonoma rates better than average: 56% fewer complaints than a typical year of the Sonoma at the same age. It is one of the best Sonoma years by this measure. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 1999 GMC Sonoma?
The brakes — 9 complaints, 16% of all complaints for this model year, most often about antilock/traction control/electronic limited slip. Next are the transmission & drivetrain (8) and seats (8).
How many recalls does the 1999 GMC Sonoma have?
NHTSA lists no recalls for the 1999 GMC Sonoma. You can still confirm with your VIN using our VIN recall check.
What are the best and worst years of the GMC Sonoma?
The best years by complaints, compared at the same age, are 2003, 1999 and 2002. Years to avoid or approach with caution: 1995, 1996 and 1998. See the full GMC Sonoma years comparison.
At what mileage do 1999 GMC Sonoma problems happen?
The median mileage reported in complaints is about 59,000 miles; 38% of problems with a recorded mileage started before 50,000 miles.
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.