This SAE Recommended Practice defines the system and component functions, measurement metrics, and testing methodologies for evaluating the functionality and performance of ground vehicle tire pressure maintenance (ATIS) systems (systems which automatically restore the inflation pressure to its specified level), and recommended maintenance practices for these systems within the known operating environments.

These systems are recommended to address all serviceable tires as originally installed on a vehicle by the OEM and/or specialty vehicle manufacturer, and for the aftermarket (including replacement or spare parts) are recommended (but optional) to address all tire/rim combinations installed after initial vehicle sale or in-use dates.

This document is applicable to all axle and all wheel combinations for the following vehicle types - single unit powered vehicles exceeding 7257 kg (16 000 lb) gross vehicle weight rating (GVWR), and multi-unit vehicle combinations, up to three towed units, which use an SAE J560 connector for power and/or communication, or equivalent successor connector technology. For combination vehicles including two or more trailers, the dolly axles are also included. The included vehicles can be newly manufactured vehicles or existing vehicles, fitted with air or hydraulic braking systems.

SPECIAL NOTE: Equipment known as ‘dual tire equalizers' are commonly used with this category of vehicles. When employing an ATIS system, dual tire equalizers systems are not recommended as they run counter to the purpose of the maintenance system.

NOTE: The following systems are not being addressed in this edition of the subject document.

1. The management system types and more mature/complex versions of maintenance and management types, to include on-board reporting/storage/retrieval data/control capabilities, will be addressed separately by future changes/additions to this document series.

2. Tire pressure monitoring systems - These systems have been addressed under SAE J2848-1.

Purpose

The installed systems for the maintenance of tire inflation pressure defined herein are on-board vehicle systems only. The maintenance type systems described herein may be controlled mechanically, electronically, and/or a combination of both, and should include sensing, restoring, and indicating/communicating, and recording (when specified by the OEM or user) capabilities. The design approach taken is expected to support the purpose and performance objectives of such a maintenance type system, and to function within the intended operating environment and design configuration of the vehicle itself.

The tire pressure system of the maintenance (ATIS) type is intended to (1) restore the tire's lost inflation gas, measured as inflation pressure, relative to the SSP (specified service pressure) under each operational stage; (2) maintain the specified service pressure level for the typical range of ambient conditions; and (3) provide the driver with indications of low uncorrected pressure(s) and system malfunction.