Es gab E32 ohne Katalysator in Exportausfuehrung fuer z B Italien und GB, in den Anfangsjahren, als das noch keine Pflicht war in diesen Laendern, und Kat Aufpreis kostete dort und einige PS schluckte. Siehe
BMW Parts Catalog
Zitat:
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Was passiert, oder womit ist zu rechnen wenn an den besagten Pins 10 und 28 Garnichts angeschlossen ist.
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Die Motronik geht dann auf feste Standardmittelwerte, die einprogrammiert sind, das ist fuer alles wie Temperatursensoren usw.
Limited Operating Strategy (LOS)
In the event of a serious fault in one or more of the sensors or their wiring circuits, Motronic will substitute a fixed default value in place of the defective sensor. This procedure is often termed limp home. A serious fault occurs when the signal from the sensor is outside of its normal operating parameters. When operating in LOS the engine may actually run quite well with failure of one or more minor sensors. Since the substituted values are those of a hot engine, cold starting and running during the warm-up period may be less than satisfactory. Also, failure of a major sensor, ie the AFS, will tend to make driving conditions less easy. Once the fault has cleared, Motronic will once more accept the live signal from the sensor. The following LOS measures are taken in the event of a failure
Component..............................Action
AFS........................substitute values are calculated from the TS position. The load signal is fixed to 6.0 ms and the ignition timing to 20° BTDC once the TS contact is open.
ATS........................substitute value of 50° C . A code will not be set, and LOS will not commence until a minimum of 3 minutes after engine start and the engine idling for a minimum of 30 seconds.
CID sensor.............injectors are pulsed simultaneously
CO pot..................substitute value of 2.77 volts
CTS...................substitute value of 80° C if ATS value is greater than 20° .
if ATS value is less than 20° , substitute value of ATS value for first three minutes after engine start-up.
OS.....................substitute value, open loop control
TS.....................substitute values, restricted engine operation
Catalytic Converter and emission control
The Motronic injection system fitted to BMW vehicles equipped with a Catalytic Converter implements a closed loop control system so that exhaust emissions may be reduced. Closed loop systems are equipped with an oxygen sensor which monitors the exhaust gas for oxygen content. A low oxygen level in the exhaust signifies a rich mixture. A high oxygen level in the exhaust signifies a weak mixture. The Oxygen Sensor closed loop voltage is quite low and switches between 100 mVolts (weak) to 1.0 volt (rich). The signal actually takes the form of a switch and switches from weak to rich at the rate of approximately 1 HZ. A digital voltmeter connected to the signal wire, would display.an average voltage of approximately 0.45 volts. In the event of OS circuit failure, the ECU substitutes a constant voltage of 0.45 volts and this should not be confused with the average voltage of 0.45 which occurs during switching from approximately 1.0 volt to 0.1 volt. When the engine is operating under closed loop control, the OS signal causes the ECU to modify the injector pulse so that the AFR is maintained close to the stoichiometric ratio. By controlling the injection pulse, during most operating conditions, so that the air/ fuel ratio is always in a small window around the Lambda point (ie Lambda = 0.98 to 1.04), almost perfect combustion is achieved. Thus the Catalyst has less work to do and it will last longer with fewer emissions at the tail pipe. The closed loop control is implemented during engine operation at engine normal operating temperature. When the coolant temperatures is below 70° C, or the engine is at full load or is on the overrun the ECU will operate in open loop. When operating in open loop, the ECU allows a richer or leaner AFR than the stoichiometric ratio. This prevents engine hesitation, for example, during acceleration with a wide open throttle. The OS only produces a signal when the exhaust gas, has reached a minimum temperature of approximately 300° C. In order that the OS will reach optimum operating temperature as quickly as possible after the engine has started, the OS contains a heating element. The OS heater is controlled by the ECU through an OS relay or from the fuel pump relay depending on vehicle. The ECU switches off the OS relay under certain conditions of speed and load.
Hab ich hier mal vor 6 Jahren gepostet
Bosch Motronic 1.1/1.3 BMW
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