T-SB-0017-14

T-SB-0017-14
March 5, 2014
Tire Inflation Pressure Compensation and Adjustment
Service
Category
Suspension
Section
Tire Pressure Monitoring
Market
USA
Applicability
YEAR(S)
MODEL(S)
2014
4Runner, Avalon,
Avalon HV, Camry,
Camry HV, Corolla, FJ
Cruiser, Highlander,
Highlander HV, Land
Cruiser, Matrix, Prius,
Prius C, Prius PHV,
Prius V, RAV4, RAV4
EV, Sequoia, Sienna,
Tacoma, Tundra,
Venza, Yaris
ADDITIONAL INFORMATION
Introduction
The purpose of this bulletin is to provide a procedure to adjust tire pressure correctly when outside
temperature is significantly colder or warmer than shop temperature.
Seasonal temperature change can dramatically alter tire pressure, which can cause the low tire
pressure warning light to illuminate.
Warranty Information
OP CODE
DESCRIPTION
TIME
OFP
T1
T2
N/A
Not Applicable to Warranty
–
–
–
–
Tire Pressure vs. Tire Temperature
Tire temperature is dependent on “cold” tire pressure, driving distance and speed, ambient
temperature and road surface temperature. As the temperature of the tire changes, air in the tire
expands and contracts, changing the tire’s air pressure. The cold tire pressure for all Toyota models
will vary and will need to be adjusted accordingly.
“Cold” tire pressure, as shown on the tire pressure label on our vehicles, is generally considered to
be the pressure in a tire that has not been driven in the past 4 hours and has been parked outdoors.
© 2014 Toyota Motor Sales, USA
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March 5, 2014
T-SB-0017-14
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Tire Inflation Pressure Compensation and Adjustment
Tire Pressure vs. Tire Temperature (Continued)
The Tire Pressure Warning System (TPWS) MUST be initialized with the tire pressure marked on the
vehicle placard. Tires are then adjusted according to the information in this bulletin to ensure that the
low tire pressure warning light does not illuminate unnecessarily.
Tire Pressure Adjustment
Figure 1. Tire Pressure Chart
1
Example 1: Cold Tires — Car Has Not Been Driven for 4 Hours and Parked Outside
2
Example 2: Warm Tires — Car Has Just Been Driven a Short Distance in Traffic
3
Example 3: Hot Tires — Car Has Just Been Driven for at Least 1 Hour of Highway Driving
4
Tire Pressure Adjustment (psi)
5
Temperature DIFFERENCE Between Seasonable Lowest Temperature and Workshop Temperature
© 2014 Toyota Motor Sales, USA
March 5, 2014
T-SB-0017-14
Page 3 of 4
Tire Inflation Pressure Compensation and Adjustment
Tire Pressure Adjustment (Continued)
Recommended Tire Pressure Adjustment:
NOTE
Use a high quality accurate tire pressure gauge, and check its accuracy regularly.
• Consider the difference of the air temperature in the workshop and the lowest ambient
temperature that may be expected in the next few weeks (especially in winter).
• Use the chart (Figure 1) to compensate for temperature of the tires when adjusting tire pressure.
• Use temperature compensation Example 1 for the spare tire.
Example 1: Temperature Compensation – “Cold” Tires
• The vehicle has been parked overnight outside shop (vehicle has “cold” tires) and tire pressures
are set to 31.9 psi.
• Workshop temperature is 68◦F, and expected lowest ambient temperature in the local area is
to be 14◦F.
• Subtract the expected lowest temperature (14◦F) from the workshop temperature (68◦F) = 54◦F.
• Using the tire pressure chart (Figure 1), find the intersection of the cold tire line at the point
corresponding to 54◦F, and read off the value on the tire pressure change axis. In this case
it would be about 4.9 psi.
• The tires should be filled to:
31.9 + 4.9 psi = 36.8 psi
Example 2: Temperature Compensation – “Warm” Tires
• The vehicle has been driven to the shop on surface streets for about 30 minutes (vehicle has
“warm” tires) and tire pressures are set to 31.9 psi.
• Workshop temperature is 68◦F and expected lowest ambient temperature in your area is
to be 14◦F.
• Subtract the expected lowest temperature (14◦F) from the workshop temperature (68◦F) = 54◦F.
• Using the Tire Pressure Chart (Figure 1), find the intersection of the warm tire line at the point
corresponding to 54◦F and read off the value on the tire pressure change axis. In this case
it would be about 6.7 psi.
• The tires should be filled to:
31.9 + 6.7 psi = 38.6 psi
© 2014 Toyota Motor Sales, USA
March 5, 2014
T-SB-0017-14
Page 4 of 4
Tire Inflation Pressure Compensation and Adjustment
Example 3: Temperature Compensation – “Hot” Tires
• The vehicle has been driven to the shop on the highway for at least 60 minutes (vehicle has
“hot” tires) and tire pressures are set to 31.9 psi.
• Workshop temperature is 68◦F, and the expected lowest ambient temperature in the area is
expected to be 14◦F.
• Subtract the expected lowest temperature (14◦F) from the workshop temperature (68◦F) = 54◦F.
• Using the tire pressure chart (Figure 1), find the intersection of the hot tire line at the point
corresponding to 54◦F, and read off the value on the tire pressure change axis. In this case
it would be about 9.0 psi.
• The tires should be filled to:
31.9 + 9.0 psi = 40.9 psi
© 2014 Toyota Motor Sales, USA