1999 GMC Yukon Denali Problems
RepairPal has identified the most common problems with the 1999 GMC Yukon Denali based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
The inside and outside door handles are prone to breaking.
The upper dash may crack, most commonly on vehicles in warm climates and exposed to a lot of sunlight. The common repair is to replace the upper instrument trim panel. Information on a technical service bulletin or extended warranty is not available at this time.
The front or rear differential may develop an abnormal noise due to worn bearings or another internal fault. Our technicians tell us that a complete overhaul of the affected differential is commonly necessary to correct this condition.
Power brake systems using "hydro-boost" may leak power steering fluid from the hydro-boost unit located behind the brake master cylinder. Replacement of the hydro-boost unit is the common repair to correct this concern.
The 99-01 GMC Yukon Denali has a known issue with the air pump check valve which causes illumination of the check engine light. There are no notable symptoms, but the vehicle will not pass state inspection or smog testing.
When the valve fails, it sticks closed, and the computer sets the code P1416. Replacement of the check valve is the only fix, as the valve is not serviceable.
The quick-connect fittings for the heater hoses tend to leak engine coolant. This problem commonly occurs because the metal housing has become brittle, which can break and cause leaks.
The windshield wipers may not work intermittently due to a faulty wiper motor control board. Our technicians tell us that lightly taping on the wiper motor when the fault occurs should temporarily get the wipers working again. Some vehicles were recalled for this problem and some were not. You will need to check with your local dealer to find out if a specific vehicle was included.
Vehicles equipped whit a 4 speed automatic transmission may develop a harsh 1-2 shift and/or illumination of the Check Engine Light with code P1870 stored. This can be caused by wear of the bore for the TCC isolator and regulator valves in the valve body. This condition does not commonly occur until the transmission reaches normal operating temperature. If the valve body is worn, replacement will be necessary to correct this concern.
A Loose or worn gas cap may cause Check Engine Light to illuminate.
The power door lock actuators may become slow to operate or stop working completely and require replacement.
It is common for the fuel level sensor in the fuel tank read the fuel level incorrectly. The sensor must be replaced to correct the condition. Our technicians recommend having the complete fuel pump module replaced on high mileage vehicles.
A clicking noise may be noted from the turn signal flasher after the turn signals are switched off. This is commonly cause by a faulty turn signal switch which will require replacement.
The 4WD transfer case encoder motor position sensor or the selector switch may fail causing the service 4WD message to be displayed. Fault code(s) stored in the transfer case control module will be of assistance in determining the exact fault causing the message to be displayed.