NHTSA lists 1 safety recall and 72 owner complaints for the 1999 GMC Sonoma. Most complaints involve service brakes, hydraulic (11) and power train (10). The EPA rates it 16–23 mpg combined.
CERTAIN DELPHI FUEL PRESSURE REGULATORS, P/NOS. FP10020-11B1, FP10026-11B1, AND FP10027-11B1, SOLD AFTER JANUARY 9, 2007, AS AFTERMARKET EQUIPMENT FOR VARIOUS PASSENGER VEHICLES LISTED ABOVE. THE UNIVERSAL PRESSURE REGULATORS (UPR) WERE PRODUCED WITHOUT AN O'RING AND RETAINER.
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
“I WAS TRAVELING ON MY JOB. I WAS IN ATLANTA GA. AND IT WAS RAINING. TRAFFIC SLOWED DOWN AND I LIGHTLY APPLIED MY BRAKES AND THEY LOCKED DOWN CAUSING THE YUKON TO SLIDE. I ALMOST HIT THE VEHICLE IN FRONT OF ME. THIS HAS HAPPENED 5 TIMES AND IT WAS RAINING EVERYTIME. THE RECALL SAID IT WAS ONLY FOR UP NORTH. I TRAVEL NORTH ALL THE TIME ON MY JOB. BUT I LIVE IN ALABAMA. SO I THINK THE RECALL SHOULD COVER MY 99 GMC YUKON ALSO.*JB”
“1999 GMC SONOMA EXPERIENCED PROBLEMS WITH TRANSMISSION, CD PLAYER, TIRES AND HEATING COIL.*MR CONSUMER CONCERNED THAT DEALER DID NOT TELL THEM THAT THERE WAS A RECALL ON THIS VEHICLE. THE TRANSMISSION WAS REPLACED, EXCHANGED REBUILT TORQUE CONVERTER WITH TRANCES FILLER 12 MONTH OR 12,000 MILE WARRANTY. *BF *NM”
“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. IS THERE AN UNDERLYING CAUSE??? ARE OTHERS HAVING SIMILAR ISSUES. I HOPE YOU CAN HELP TO GET A HANDLE ON THIS FOR ME AND, POTENTIALLY, FOR OTHERS, TOO. THANK YOU. *JB”
Towing, payload and dimensions aren’t in the EPA or NHTSA data, so we don’t list them.
| Version | City | Hwy | Comb. | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|
| Sonoma 2WD Man 5-spd, 4 cyl, 2.2 L · Rear-Wheel Drive | 20 | 26 | 23 | $2,800 | 386 |
| Sonoma 2WD Auto 4-spd, 4 cyl, 2.2 L · Rear-Wheel Drive | 17 | 24 | 19 | $3,400 | 468 |
| Sonoma 2WD Man 5-spd, 6 cyl, 4.3 L · Rear-Wheel Drive | 15 | 21 | 18 | $3,550 | 494 |
| Sonoma 2WD Auto 4-spd, 6 cyl, 4.3 L · Rear-Wheel Drive | 15 | 20 | 17 | $3,800 | 523 |
| Sonoma 4WD Man 5-spd, 6 cyl, 4.3 L · 4-Wheel or All-Wheel Drive | 15 | 20 | 17 | $3,800 | 523 |
| Sonoma 4WD Auto 4-spd, 6 cyl, 4.3 L · 4-Wheel or All-Wheel Drive | 14 | 19 | 16 | $4,000 | 555 |
| Item | Miles | Time | Note |
|---|---|---|---|
| Engine oil & filter | 5,000–10,000 mi | 6–12 months | Follow the oil-life monitor if fitted |
| Tire rotation | 5,000–7,500 mi | Every oil change | Check pressure monthly |
| Engine air filter | 15,000–30,000 mi | 1–2 years | Sooner in dusty areas |
| Cabin air filter | 15,000–25,000 mi | 1–2 years | |
| Brake fluid | — | 2–3 years | Absorbs moisture over time |
| Coolant | 60,000–100,000 mi | 5–10 years | Long-life coolants last longer |
| Spark plugs | 60,000–100,000 mi | — | Iridium/platinum plugs at the long end |
| 12V battery | — | 3–5 years | Heat shortens battery life |
1 safety recall as of Oct 30, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.
Owners filed 72 complaints with NHTSA. The most-cited components are service brakes, hydraulic (11), power train (10), seats (8). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.
The EPA rates the 1999 GMC Sonoma at 16–23 mpg combined, depending on engine and drivetrain (6 versions rated).