alarm BMW 8 SERIES 1998 E31 Drive Away Protection Syst

7
EWS
• 4 cylinder =1800 RPM
• 6 or 12 cylinder =1200 RPM
• 8 cylinder =900 RPM
The relay contacts will close when the exceeded Hz value drops to 5Hz below the maxi-
mum value. This is intended as a safety feature to prevent starter motor activation when the
engine is running above these speeds.
Output
The DME receives a High/Low signal from the Starter Immobilization Relay. When the sig-
nal is High, the DME does not activate injector or ignition operation.
DWA (E31)
The DWA outputs a High/Low signal to the Starter Immobilization Relay indicating the con-
dition of the alarm system. A High signal indicates the alarm is armed, preventing vehicle
starting.
Principle of Operation
The EWS Starter Immobilization Relay receives it’s inputs from the Ignition switch, GM (or
DWA), BC, Trans Range Switch and the DME (after 6/94). The relay will prevent engine
starting if:
• The vehicle is locked from the outside. The GM receives the High signal from the
door lock switch and sends a High signal to the EWS.
• The BC Code function is set.
• A DWA High signal is received. (E31only)
• A Low signal is received from the Trans Range Switch.
• The engine speed signal from the DME exceeds 60Hz. (after 6/94)
The Ignition and injection functions of the DME are disabled and the KL50 start signal to
the starter is opened to prevent starter operation.
Workshop Hints:
Starter Immobilization Relays are different for manual and automatic vehicles, check to ensure correct
relay is installed.
The Starter Immobilization Relay is not on the Diagnostic Link. Conventional troubleshooting techniques
using the DISplus, a DVOM and the correct ETM are necessary.
Loss of input from the GM or BC will allow the engine to start.
Loss of input from the Trans Range Switch will NOTallow the engine to start.