check engine BMW X5 2005 E53 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.

18
EWS
Clutch Switch
A Hall-Effect Switch is added to the clutch system to inform the EWS III (3.2) control mod-
ule of clutch status. Input from the switch replaces the signal from the Trans Range Selector
Switch on manual transmission equipped vehicles. High signal status indicates the clutch
is depressed and vehicle starting is allowed.
Principle of Operation
The starting sequence for the EWS III (3.2) is as follows:
• The key is inserted into the lock cylinder and switched “ON”. The EWS III control mod-
ule is powered through KL R and sends a 125kHz AM signal to the ring antenna. The
AM signal induces voltage in the key coil and powers up the transponder.
• Powered up, the key transponder sends the key identification code to the EWS III mod-
ule. The EWS III module verifies the key identification code and checks to see if the key
is enabled. If the key is correct and enabled, a password is sent to the transponder over
the 125kHz AM signal through the ring antenna.
• When the transponders accepts the password, it releases the changing code, which it
received from the EWS III module during the last start-up operation, to the EWS III mod-
ule via the ring antenna.
• The EWS III module compares the changing code received from the transponder with
the code stored in its memory and if they match the process is allowed to continue.
The EWS III module looks at the other inputs for correct status (e.g. Code function not
active, Transmission in P or N or clutch depressed, engine speed below specified RPM)
and energizes the the internal relay to begin starter operation.
• As the starter begins to operate, the EWS III module sends the ISN to the DME and if
verified as correct by the DME, drive away protection is cancelled and injection and igni-
tion is enabled. The EWS III module also sends a new changing code to the key
transponder through the ring antenna.
Replacement Procedures
Keys
Up to 6 additional keys may be ordered as replacement keys. The EWS III (3.2) module is
codeable for only 10 keys (4 delivered with vehicle and 6 replacement). The keys are
mechanically matched to the vehicle with the lock tumblers and electronically matched to
the EWS III (3.2) through unalterable coding.

21
EWS
DME Control Module
The DME Control Module has changed in that it is not the source of the ISN but now only
stores the “Rolling Code”. It compares the “Codes” to those sent to it by the EWS III (3.3)
control module. The “Rolling Code Table” assigned to the DME must match the table in the
EWS III (3.3) module. The “Rolling Code Table is “burned” into the DME during the pro-
gramming of the DME and cannot be change once “burned”.
Transmission Range Selection Input
With the introduction of the SKE type connectors on Transmission Control Modules the
direct input from the Transmission Range Selector Switch is eliminated. The input for range
selection is now received from the AGS Control Module.
On manual transmission vehicles clutch status is input directly into the DME.
Principle of Operation
The starting sequence of the EWS III (3.3) is as follows:
(Same as EWS III (3.2)
• The key is inserted into the lock cylinder and switched “ON”. The EWS III (3.3) control
module is powered through KL R and sends a 125kHz AM signal to the ring antenna.
The AM signal induces voltage in the key coil and powers up the transponder.
• Powered up, the key transponder sends the key identification code to the EWS III (3.3)
module. The EWS III (3.3) module verifies the key identification code and checks to see
if the key is enabled. If the key is correct and enabled, a password is sent to the
transponder over the 125kHz AM signal through the ring antenna.
• When the transponders accepts the password, it releases the changing code which it
received from the EWS III (3.3) module during the last start-up operation to the EWS III
(3.3) module via the ring antenna.
• The EWS III (3.3) module compares the changing code received from the transponder
with the code stored in its memory and if they match the process is allowed to contin-
ue. The EWS III (3.3) module looks at the other inputs for correct status (e.g. Code func-
tion not active, Transmission in P or N or clutch depressed, engine speed below spec-
ified RPM) and energizes the the internal relay to begin starter operation.

25
EWS
Under certain condition “Alignment” of the DME and EWS III D modules may still be nec-
essary. The alignment procedure only resets the code table to code #1 it does not change
the “Rolling Code Table”.
Key Activation
Keys that are lost or stolen may be deactivated or made to not operate the starter func-
tions. The SERVICE FUNCTIONS of the DISplus or MoDic for EWS III D contains a
“bar/release code” function that activates and deactivates keys of the EWS III D. Any key
may be “Barred” except the key in the ignition at the time of deactivation. The lost or stolen
key can be identified by the identification of the remaining keys.
There is no limit to the number of times a key can be activated/deactivated.
8510130
Pin Assignments
EWS III D
Workshop Hint:
With E46 Style diagnostics, check the following status’ in Diagnosis, Control Unit Functions, EWS:
• Starter Status:
Park/Neutral, BC Code active, Engine Speed, Double lock status, Starter Enabled
• Key Status:
Transmits, Changing code, Key I.D., Key number, Key Password, Key disabled
• DME Wire Status
• Selector lever/Clutch Status • Central Locking Status • Input Power •BC Code via K-Bus