Toyota Tacoma (2015-2018) Service Manual: Diameter of the Tire is not Uniform (C1337)

Toyota Tacoma (2015-2018) Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Vacuum Brake Booster) / Diameter of the Tire is not Uniform (C1337)

DESCRIPTION

The skid control ECU (brake actuator assembly) measures the speed of each wheel by receiving signals from the speed sensors. These signals are used for recognizing whether all 4 wheels are operating properly. Therefore, all wheel signals must indicate the same speed.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1337	Diameter of the Tire is not Uniform	The following occurs in 3 consecutive trips: At a vehicle speed of 20 km/h (12 mph) or more, there is a difference of 20% or more in the average speed between the front wheels and rear wheels for 20 seconds or more.	Tire and wheel size Tire deformation Skid control rotor Speed sensor Speed sensor circuit Skid control ECU (Brake actuator assembly)

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1337

Diameter of the Tire is not Uniform

The following occurs in 3 consecutive trips:

At a vehicle speed of 20 km/h (12 mph) or more, there is a difference of 20% or more in the average speed between the front wheels and rear wheels for 20 seconds or more.

Tire and wheel size
Tire deformation
Skid control rotor
Speed sensor
Speed sensor circuit
Skid control ECU (Brake actuator assembly)

CAUTION / NOTICE / HINT

NOTICE:

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information (See page PROCEDURE ).

PROCEDURE

CHECK DTC

(a) Check if any DTCs relating to the speed sensor circuit are output (See page Result ).

Result

Result	Proceed to
DTC is not output	A
DTC is output	B

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

2.	CHECK TIRE SIZE

(a) Check the tire size and condition of all 4 wheels.

OK:

All 4 tires are the same size and in the same condition.

REPLACE TIRES SO THAT ALL 4 TIRES ARE SAME SIZE AND IN THE SAME CONDITION

3.	RECONFIRM DTC

(a) Clear the DTC (See page (b) Turn the ignition switch off. ).

(b) Turn the ignition switch off.

Turn the ignition switch to ON and start the engine, drive the vehicle at a speed of 30 km/h (19 mph) or more for at least 30 seconds, and then stop the vehicle and turn the ignition switch off.

(d) Check if the same DTC is output (See page Result ).

Result

Result	Proceed to
DTC is output	A
DTC is not output	B

REPLACE BRAKE ACTUATOR ASSEMBLY

USE SIMULATION METHOD TO CHECK

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