2002 2BMXV03.0LER, 2BMXV03.0M5R & 2BMXT03.0E5R
WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 2002 BMW Z8, 2002 BMW Z3, 2002 BMW X5, 2002 BMW M5, and 2002 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
- Catalyst Monitoring Based On Monitoring Oxygen Storage Capability - Engine closed loop feedback control generates lambda (air/fuel ratio) oscillations in exhaust gas. These oscillations are dampened by oxygen storage activity of catalyst. Amplitude of remaining lambda oscillations downstream of catalyst indicate storage capability.
- Monitoring Procedure - In order to determine catalyst efficiency a fixed number of complete lambda controller cycles (oxygen oscillation from upstream sensor) are used to calculate areas which are enclosed by controller cycle curve and is also calculated mean value. Average of all areas display magnitude of oxygen admission to catalytic converter. See Fig 1. Then original measured oscillation (average of areas) from downstream sensor is compared to calculated maximum permissible value. A fault is detected if quotient (measured to calculated value) is greater than a fixed number. See Fig 2.