6-47 Uniform Tire Quality Grading
Quality grades can be found where applicable on the tire
sidewall between tread shoulder and maximum section
width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance.
(This applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter
-type snow
tires, space
-saver or temporary use spare tires, tires with
nominal rim diameters of 10 to 12 inches (25 to 30 cm),
or to some limited
-production tires.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course.
For example, a tire graded 150 would wear one and
a half (1 1/2) times as well on the government course
as a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart significantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction
-- AA, A, B, C
The traction grades, from highest to lowest, are AA,
A, B, and C. Those grades represent the tire's ability to
stop on wet pavement as measured under controlled
conditions on specified government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight
-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
6-64
Fuses Usage
20 Windshield Wiper/Washer Motor
and Switch
21 Turn Signal Switch
22 Rear Electric Accessory
Plug Housing
23 DRL Control Module
24 Not Used
25 Rear Window Defogger Relay,
Heated Mirrors
26 OnStar
27 Inflatable Restraint
Control Module
28 Heater
-A/C Control
29 Instrument Cluster, BCM,
Electronic Level Control (ELC)
Sensor and Relay
30 Stoplamp Switch
31 Module/Electronic Brake Control
Module/Electronic Brake Traction
Control Module (EBCM/EBTCM)Fuses Usage
32 Evaporative Emissions (EVAP)
Canister Vent Solenoid Valve
33 Not Used
34 ELC Air Compressor and ELC
Relay, Trailer Harness
35 Courtesy Lamp
36 BCM, Electronic Brake Control
Indicator Lamp Driver Module,
Instrument Panel Cluster, Rear
Side Door Actuator Control
Module, Rear Windows
37 Rear HVAC
-A/C Control
38 Rear Window Wiper Motor, Rear
Window Wiper/Washer and
Multifunction Switch (Rear
Window Wiper/Washer Switch)
39 Not Used
40 Not Used
41 Not Used
42 Not Used
