Frage zu Unterspannung M70: ASC, Kaltstart...

[Erich]

und was sagt die Batterie? Der Fehler kann ja auch durch eine zu schwache Batterie kommen. Batterie Testen/Laden, Fehler loeschen, wieder fahren und noch mal auslesen.

Das hab ich noch gefunden:

Advanced BMW ABS hints and tips

MICROPROCESSOR CONTROLLED ABS(uC-ABS)STORES ERRONEOUS INTERNAL DEFECT FAULT
MODELS AFFECTED: 7series(E32)-vehicles produced 06/91 and later, equipped with M30 engine.
5 series (E34)-vehicles produced 9/91 and later.
FAULT: Increasing number of uC-ABS control units are being returned for showing internal defect during troubleshooting and readout of the fault memory. In most cases the fault is erroneous.
CAUSE: If the ignition is switched on with the cap of the D100 diagnostic connector removed, the erroneous fault can be set by a low voltage condition on the TTD lead to this control unit.
SOLUTION:
-Erase the fault in the uC-ABS fault memory, while the diagnostic module is still connected and the ignition is switched on.
-Before disconnecting the diagnostic cable, switch off the ignition
-Reconnect the cap for the D100 diagnostic connector, then switch on
the ignition again.
-Do not replace control unit.


ABS WARNING LIGHT COMES ON
MODELS AFFECTED: All with ABS
FAULT: ABS warning light comes on intermittently. Normal troubleshooting procedures find no defect.
CAUSE: If cars have recently had two new tires, or snow tires put on. Sometimes when the car is driven over 50 MPH.
SOLUTION: Check all four tires on the car, make sure they are the same brand, style, and size. Check if any of the new tires have substantially more tread than the rest. These differences may cause enough
variance in rolling diameters to confuse the ABS control unit, which intern gives a false signal to the ABS warning light.


ABS, ASC, AND ASC+T MALFUNCTION
MODELS AFFECTED: All models equipped with ABS,ASC OR ASC+T
FAULT: Any of the ABS ASC and ASC+T systems inoperative, intermittently inoperative, or illuminating the warning lamp.
CAUSE: All BMW'S with slip control systems use 4 wheel speed sensors which monitor each wheels speed of rotation with a high accuracy. The system control unit uses this information to calculate a vehicle speed. In this way it detects wheel speed variation. If the inputs vary from each other by a certain amount, the control unit is not able to do the calculation reliably (plausibility fault) and takes its self off-line as a safety precaution(fail-safe).This can be because the wheels and tires are non-approved partsand therefore do not agree with the system.SOLUTION: Make sure the vehicle is fitted with BMW approved wheels and tires. Then do further
diagnostic testing to check if fault is resolved.


ENGINE APPEARS TO MISFIRE OR STUMBLE INTERMITINTLY
MODELS AFFECTED: 5 Series(E34), 7 series(E32), 8 series(E31) all equipped with ACS.
FAULT: Under certain specific conditions an apparent engine misfire or bucking may occur. This is not an engine misfire.
CAUSE: Short (less than 100 milliseconds) fuel injection cut-off, as a result of MSR (engine drag torque control) regulation. This is a normal ASC function that may occur under these conditions:
-The vehicle is equipped with ASC
-Vehicle speed between 45 and 60 MPH
-A rough road surface (e.g. potholes, railroad tracks)
-Light throttle(accelerator pedal only depressed 1/8)
-ASC not switched off.
SOLUTION: Replace the ASC control unit. no further diagnosis of the ABS/ASC system should be necessary.