T-SB-0020-12 Rev1

January 24, 2012

CP) TOYOTA

Technical Service Bulletin

Tire Inflation Pressure Compensation and Adjustment

Service

Category Suspension

Toyota Supports
ASE Certification

Section Tire Pressure Monitoring Market USA

Applicability
YEAR(S) MODEL(S} ADDITIONAL INFORMATION
2013 4Runner, Avalon,

Avalon HV, Camry,
Camry HV, Corolla, FJ
Cruiser, Highlander,
Highlander HV, Land
Cruiser, Matrix, Prius,
Prius C, Prius PHV,
Prius V, RAV4,
Sequoia, Sienna,
Tacoma, Tundra,
Venza, Yaris

REVISION NOTICE
October 16, 2012 Rev:

vehicles.

Any previous printed versions of this bulletin should be discarded.

* Applicability has been updated to include 2013 model year Avalon HV, Prius C, and Prius PHV

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 tire pressure

warning lamp to illuminate.

Warranty Information

OP CODE DESCRIPTION TIME OFP T1 T2
N/A Not Applicable to Warranty a = a a
© 2012 Toyota Motor Sales, USA Page 1 of 4
CG) TOYOTA T-SB-0020-12 Revi January 24, 2012 Page 2 of 4

Tire Inflation Pressure Compensation and Adjustment

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.

The 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 TPWS light does not
illuminate unnecessarily.

Tire Pressure Adjustment
Figure 1. Tire Pressure Chart

14
13
12
11

=
a

o 2-2 N WwW hb ww aA Sm Uw

O°F 18°F 36°F 54°F 72°F 90°F 108°F

©

ees Example 1: Cold Tires — Car Has Not Been Driven for 4 Hours and Parked Outside

= aan = Example 2: Warm Tires — Car Has Just Been Driven a Short Distance in Traffic

seann Example 3: Hot Tires — Car Has Just Been Driven for at Least 1 Hour of Highway Driving

Tire Pressure Adjustment (psi)

oe ee

Temperature DIFFERENCE Between Seasonable Lowest Temperature and Workshop Temperature

© 2012 Toyota Motor Sales, USA
CP) TOYOTA T-SB-0020-12 Revi January 24, 2012 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 focal 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

© 2012 Toyota Motor Sales, USA
CP) TOYOTA T-SB-0020-12 Revi January 24, 2012 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

© 2012 Toyota Motor Sales, USA