Elektrik: Central Locking/Windows/sunroof inoperative Tech Bulletin

[Erich]

das ist ein interessanter Artikel, falls Zentralschliessung/Fenster und Schiebedach nicht funktionieren sollten:
aus:
 http://germanautospecialists.com/Newsletter3.html



MODELS: 5 series (E34), 7 series (E32)


Situation: The above mentioned vehicles are equipped with a General Module which controls a Power Protection Relay (sometimes referred to as an "electronic fuse"). This Power Protection Relay interrupts the flow of current to three ZKE subsystems (power windows, sunroof, central locking, and door lock heating) in the event of excessive current flow, such as a short circuit. The General Module not only monitors the activation of the heating element, but also checks the integrity of the element. An open circuit of the door lock heating element circuit will cause the General Module to open the Power Protection Relay, thereby removing power from the Central Locking and Power Windows, Sunroof circuits.

Correction: If a complaint is encountered of intermittently inoperative Central Locking or Power Windows, Sunroof, proceed with normal troubleshooting using the BMW Service Test and Diagnostic Procedures Manual. Power Protection Relay status must be "on" for the Central Locking and Power Windows, Sunroof to work. If these procedures fail to correct the complaint, verify that the circuit is intact from the General Module (E32: Pin 14 of connector X254; E34: Pin 26 of connector X253), through the Relay Module and Door Lock Heating Element to ground. Total resistance of the circuit should be approximately 992-996 ohms (2-3 ohms for the heating element and approximately 990 ohms through the relay module). If not, refer to the appropriate ETM for troubleshooting.

[JB740]

wo du es nur immer auftreibst

gruß jürgen

[Stefan2912]

Gratulation

Wenn ich es nur immer richtig verstehen könnte

Grüsse
Stefan

[Erich]

wenn Du einzelne der Fachwoerter nicht verstehst im Englischen, hier ist von Kiessling-Racing ein spezielles Woerterbuch Deutsch-Englisch-Deutsch fuer die "Rennmonteure"
 Kfz-Technische Worte

[Erich]

der gute Patrick Leung von roadfly muss natuerlich sofort alles nachrechnen und hat anscheinend einen Fehler gefunden. Ich kopier das mal hier:

Heating element should have more resistance

May be the bulletin has a typo: it's more likely that the relay module to have 2-3 ohms and the heating elements to have 990 ohms. When 12 VDC is applied, current through the series connection will be approx. 12.1 milliAmp. Power to the heating element hence will be R*(I^2)=0.15 Watts, which IMO is still too low to give out any heating effect.
Patrick C 88 750 144K
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