Test Group XBMXV02.8M52 & XBMXV02.5M52

WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 1999 BMW Z3, 1999 BMW M3, 1999 BMW M Roadster, 1999 BMW M Coupe, and 1999 BMW 750iL. However, it is still accessible from the selected car via links, so may be relevant.

General Description - Evaporative system monitoring permits detection of leaks in evaporative emission control system with a diameter of .039" (1 mm) and greater. Evaporative emission control system is hermetically sealed off from atmosphere by means of a shut-off valve at charcoal canister. When purge valve opens, engine generates a vacuum in tank. After closing purge valve, pressure increase is measured by a tank pressure sensor. If vacuum increases above a defined threshold, a leak is detected. As part of vacuum, check purge flow is verified. See Figure-Fig 4 .

Fig 1: EVAP System Monitoring Structure

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: EVAP System - Test For Vapor Generation

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 3: EVAP System - System Diagnosis Flow Chart

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 4: Monitoring Structure Of Evaporative Purge System

Courtesy of BMW OF NORTH AMERICA, INC.