Emissions - I/M Loaded Mode Test Using 2WD Dynamometer

PRODUCT GENERAL INFORMATION
PG016-01

August 31, 2001

Title:
LOADED I/M TEST FOR NON-SWITCHABLE TRACTION CONTROL VEHICLES

Models:
'01 All Models

Introduction





Dyno meter Applicability

Some state Inspection/Maintenance programs require a loaded mode test conducted on a dynamometer. A loaded mode test using a 2WD dynamometer cannot be performed on vehicles with full time four wheel drive or "non-switchable" traction control vehicles. A list of these vehicles are shown for 2001 models.

The switchable status of the 2001 model year 4Runner and Sequoia traction control systems may be confusing, so an explanation is provided below.

The "CENTER DIFFERENTIAL LOCK" switch on the 2001 4Runner 4WD and the "VSC OFF" switch on the 2001 4Runner 4WD and Sequoia 4WD models do not deactivate traction control action. There is no combination of switch setting and 2WD/4WD selector position that can achieve deactivation of traction control on these models. Therefore, the 2001 4Runner 4WD and Sequoia 4WD are non-switchable traction control types and cannot be tested on 2WD dynamometer without special service procedures inappropriate for I/M use.

The traction control (TRAC) function on 4Runner 2WD and Sequoia 2WD models can be disabled with a dashboard mounted "TRAC OFF" switch. Disablement of TRAC is not intended for regular driving, so TRAC is reactivated above 19 mph even if the switch was turned off. However, vehicle speed on these 2WD models is sensed from a front wheel, and the driving wheels are on the rear axle, so the front wheels will not rotate on a 2WD dynamometer and TRAC will not reactivate.

Therefore, for purposes of I/M testing, 4Runner 2WD and Sequoia 2WD models are "switchable" traction control types and can be tested on a 2WD dynamometer.

Applicable Vehicles

^ 2001 model year All Models.





Warranty Information