EVAP System - Special Tool Usage: Overview
File In Section: 06 - Engine/Propulsion SystemBulletin No.: 01-06-04-044
Date: November, 2001
INFORMATION
Subject:
Test Guidelines for Use of Essential Tool J 41413-200 Evaporative System Tester
Models:
2002 and Prior Passenger Cars and Light Duty Trucks with Non-Enhanced and Enhanced EVAP Systems
The J 4141-200 Evaporative Emission System Tester (EEST) updates the J 41413 Evaporative Pressure/Purge Diagnostic Station. Continue to use the appropriate Service Information substituting the J 41413-200 Evaporative Emission System Tester (EEST) and this bulletin procedure in any diagnostic step requiring the use of the J 41413. This includes the Inspection Maintenance (I/M) Emissions Diagnostic Manual Pre-OBD II GMPT/97-IM240.
Some 1996 to 1998 and all 1999 and newer GM cars and light trucks are required to illuminate the malfunction indicator lamp (MIL) when the On-Board Diagnostic (OBD II) system detects an evaporative emissions (EVAP) system leak equivalent to an orifice of 1 mm (0.040 in) diameter or greater. In model year 2000, GM introduced software on some vehicles which requires illumination of the MIL when the OBD II system detects an EVAP system leak equivalent to an orifice of 0.5 mm (0.020 in) diameter or greater. The new J 41413-200 EEST can be used on all GM cars and light duty trucks.
GM cars and light duty trucks that meet this new standard cannot be diagnosed using the existing ultrasonic leak detection equipment. The new J 41413-200 EEST can be used to identify leaks and to verify repairs.
The J 41413-200 EEST introduces chemically inert smoke into the sealed EVAP system under low pressure. System leaks are located by using the J 41413-SPT high intensity white light to inspect for traces of smoke escaping from the sealed EVAP system.
DISCLAIMER