The immobilizer would NOT let the starter crank....

From the symptoms you wrote, I would suspect the ignition switch. All of the contacts in the switch do not seem to me making the connection, showing partial power to the car.... The E46 crowd has has some issues with this switch also......

Take the steering column trim off, and pull the connector (large 1.5" x 1.5" connector on the left side of the column) off of the ignition switch. Do a visual and check or corrosion and vertiges on the pins. Reinstall.

That is the obvious. The next step would be to replace the switch.

Also, THANK YOU for a nice list of symptoms...... instead of 'my car will not start', which is what we normally get on this forum....

 

Thanks Shipkiller,

The starter turning and blocked immobilizer are, indeed, symptoms that are not very compatible but I thought that some failure in the EWS module might still allow the starter to crank but block fuel and sparks... Apparently, that's hardly the case.

Anyhow, will have a look at the ignition switch one of these days and will report on my observations. Another thing that struck me today was that the car would start and drive with only the small plastic key which is supposed to only be capable of unlocking the car.

Oh, yes, being a R&D engineer I know how important it is to describe the symptoms as fully as possible... Thank you again for the help, it's much appreciated!

 

The EWS module energizes the power relay to the starter...

 

Sure, but I thought this circuit might be OK while the one (if separate, of course) that feeds signal to the DME is damaged and works intermittently. Need to read the diagrams but too little time recently.

 

Here are the schematics...

 

Oh, thank you so much! That's very useful!

 

According to page 20-21 of this document "computersolutions. cn/blog /wp-content/uploads/2011/02/BMW_EWS.pdf" (remove the spaces where needed in order to browse it) it is possible for the starter to crank but the engine start to be banned by the DME) - sounds pretty much like my symptoms. In this case, the EWS recognizes the key but fails to agree with the DME on the "rolling code" hence the DME refuses to start the engine (ignition and fuel injection are banned). No idea, however, which lights are illuminated on the instrument cluster in this condition. Most probably all of them.

So far could not find the wiring diagrams of the DME and the EWS in order to see what is powered by which contact of the ignition switch. In case the DME and the EWS are powered from different sources/contacts my symptoms would be very consistent with possible power failure of the DME while the EWS would be working fine (i.e. recognizing the key and cranking the engine).

 

Ordered the ignition switch (the equivalent of about 105 USD here). The replacement seems to be a PITA since according to the TIS I have to remove the wheel and even the airbag module in order to remove the steering column trim. Crazy!

 

OK, finally had a look at the wiring diagrams on http://www.bmw-planet.com

As it turns out, the EWS module is powered constantly via terminal 30 (fuse 10, 5 Amps) of the fuse-box plus (for safety reasons) redundantly by terminal R (fuse 12, 5 Amps) of the fuse-box. For turning the starter motor it does not need any communication (via the X1659 connector) with the DME module. It only needs to recognize the transponder of the key. The starter is directly connected and controlled by the EWS module. This means that even if no voltage is supplied by the ignition key in position 2, the EWS module will crank the motor provided it recognizes the transponder of the key.

 

More information for you to look at, directly out of the WDS:

Electronic Vehicle Immobilisation System EWS 3.3
The EWS 3.3 serves as an antitheft alarm system and enables the start of BMW vehicles.

A transponder chip is integrated in each of the vehicle keys. A ring coil is mounted about the ignition lock. The transponder chip is powered by the EWS3 control module via this coil, i.e. no battery is required in the key. The power supply and data transfer take place in the same way as a transformer between the ring antenna (coil) at the ignition lock and the transponder chip integrated in the key.

The key then sends data to the EWS3 control module. If this data is correct, the EWS3 enables the starter by way of a relay installed in the control module and additionally sends a coded start enable signal via a data link to the DME/DDE.

Components
Key with integrated transponder chip
A chip which can both transmit as well as receive (transponder) is integrated in the key. This transponder chip obtains its power from the field built up by the ring coil and uses it to communicate with the EWS3 control module. This means that no battery is necessary in the key for power supply. Every key or the transponder integrated in it is a unique part. The control module can also differentiate between the individual keys. The key transmits and receives data from/to the EWS control module.

If errors occur during communication between the EWS3 control module and the individual keys, these errors are stored in the fault memory - separate for each individual key.

Ring coil
The ring coil is mounted on the ignition lock and serves as an antenna for communication between the transponder chip (in the key) and control module.

EWS 3.3 control module
The EWS 3.3 control module communicates with the key mounted in the ignition lock. If the communication procedure is correct and the key has sent all data necessary for identification and start enable to the control module, the control module detects whether the key is valid and has been released for use. If this is the case, it releases the starter relay located in the control module and sends a coded enable signal via the data link to the DME/DDE.

The control module can manage a maximum of 10 keys allocated to the control module, i.e. a maximum of 6 replacement keys are possible.

The control module can identify the individual keys thus making it possible to disable/enable individual keys and to store fault codes for each individual key separately in the fault memory.

Data link to DME/DDE
The EWS3 control module sends a coded enable signal to the DME/DDE via the data link. The engine cannot be started before this signal has been transferred.

Engine control module (DME/DDE) with coded start enable input
The engine control module (DME/DDE) only enables ignition and fuel supply if a correct enable signal is received from the EWS control module.

EWS-DME/DDE interface
Identical variable codes are stored in the EWS 3.3 control module and in the DME/DDE control module. The value of these codes changes after every start procedure. Engine start is only enabled when the code sent by the EWS control module agrees with the code in the DME/DDE control module.

The control modules are allocated only during initial programming of the DME/DDE control module. The engine control module then adopts the basic code of the EWS control module.

Important

It is not possible to replace the DME/DDE or EW 3.3 control modules for test purposes!

In the case of certain faults, it is possible that the variable codes in both control modules deviate from each other. In these cases it is possible to calibrate the variable codes by means of the service function ”EWS - DME/DDE calibration”.

Influencing variables
P/N input for automatic transmission
Whether the vehicle is equipped with automatic transmission is defined in the coding.

On automatic vehicles, a start procedure is enabled by the EWS3 only if the selector lever is in position P or N.

The EWS3 control module receives the information with regard to the selector lever position twice:

Via a data link

Via the K-bus

If the information ”selector lever in position P or N” is sent only via the K-bus but, due to a fault, not via the data link, noticeable start delays within the range of 1 - 2 s can occur.

”Central locking secured” signal
The EWS3 control module receives this information via the K-bus.

If the EWS3 control module receives the ”central locking secured” signal from the general module, in ignition lock position 1 (terminal R), the EWS sends back a signal via the K-bus which unlocks the central locking.

Run-on time
Important

For safety reasons, the EWS3 control module features a code-dependent run-on time (approx. 10 seconds). It begins when the ignition lock is switched to 0 position. Within this run-on time start with any mechanically fitting key is enabled.

Key identification and start procedure
The following procedure takes place after inserting the vehicle key in the ignition lock:

The transponder in the key is powered via the loop antenna and sends the key data to the EWS3 control module.

The EWS3 control module then checks the key data to ensure it is correct and only then sends an enable signal to the engine management system and starter.

After the engine has started, the EWS3 control module generates new key data (change code) and transfers them to the transponder in the key.

A new variable code is also created and stored in the DME/DDE control module.

Changing individual components
Key
Replacement keys can be obtained from a sales point only via a BMW dealer where one of the 6 replacement keys fitting the vehicle is programmed. This key is not a copy of the lost key, but rather a new key.

A total of not more than 6 replacement keys suitable for the installed EWS control module can be made and handed over.

There is a noticeable start delay of 1 - 2 s when a new key is inserted in the ignition lock for the very first time. From then on, the start procedure should take place without delay.

Lost keys must be blocked by means of diagnosis. Refer to ”Special features of the diagnosis program”.

CAUTION!

Each request for a key is documented so that inquiries from insurance companies and authorities can be followed up.

Procedure for loss of all 10 keys
A new EWS control module is required if all 10 keys are lost.

By providing all the necessary data, it is possible to obtain a new EWS control module from a BMW dealer and the new transponder keys allocated to it with the previous mechanical key code.

EWS control module
The following procedure should be adhered to when replacing the EWS 3.3 control module:

Before replacing the EWS3 control module: Leave defective control module installed in vehicle and in the coding program (Encoding ZCS) select point ”1 New coding - 1 Replace control module - 1 Read out data from defective control module”. Coding data and vehicle-specific data is read out of the EWS control module with this part of the program and buffered in the MoDiC or DIS tester.

Now install new EWS 3 control module.

After replacing the control module: Encode new EWS 3 control module with coding program selection point ”1 New coding - 1 Replace control module - 2 Transfer data to new control module and encode control module”. The buffered data is now transferred and EWS - DME/DDE calibration is carried out.

Note

The procedure described above must be adhered to as all the data necessary for vehicle identification is also stored in the EWS control module. It will be necessary to do without the data readout from the old control module only if the EWS 3 control module no longer has diagnostic capabilities.

Proceed as follows in this case:

Install new EWS control module in the vehicle and encode with the encoding program and selection point ”1 New coding - 2 Re-encode control module”.

Then carry out matching with selection point ”EWS - DME/DDE calibration”.

In this procedure, the vehicle data necessary for automatic vehicle identification cannot be written to the EWS control module.

Replacement of engine control module (DME/DDE)
After replacing the engine control module, ”EWS - DME/DDE calibration” must be conducted with the coding program or in the diagnosis program.

 

Thank you! This is exactly the information that I read from the website mentioned in one of my previous posts. So far all the clues lead to the conclusion of a faulty contact switch. I only wonder whether to replace it right away or first measure voltages while the symptom is there. I can almost bet there will be no voltage to the DME in this case.

 

OK, this weekend was sunny. Finally decided to cancel my mountainbiking and (among other things) replace the ignition switch.

Since this was the first steering column trim removal of that car, decided to follow the procedure described in the TIS. This means removing the negative terminal of the battery, removing the airbag unit and removing the steering wheel. All this (luckily quite straight-forward and easy to do) in order to get (VERY LIMITED) access to the locks that keep the upper and the lower trim together. :thumbdwn: I want to see the face of the idiot who designed it that way. I have worked on many other cars (including French ones who are infamous for the silly engineering solutions) but had not yet seen anything more idiotic than the way this trim is held together. About two decades ago BMW was a symbol of brilliant engineering and ease of repair. Apparently those days are gone with no trace.

Another thing that shocks me is how fragile and cheap virtually any plastic part of this car is! Even if one does everything by the book, it is a pure matter of luck not to break something. When it comes to plastics and trim components, my 16-year old Renault is a damn Rolls-Royce compared to one of the most expensive Bimmers. Shame on you, people of BMW!

Anyway, replaced the switch and tested the car - everything works fine now. I just need to re-teach the anti-pinching system of the power windows but will do that tomorrow. Will disassemble the old switch to see if there is anything visibly wrong with the contacts. On testing it with a multi-meter it works seemingly fine but...

Specially for Shipkiller: thank you very much! Your help is, as usual, highly effective and highly appreciated.

 

same issue no crack no start no sound no nothing I change out my ignition switch already bc I thought that was the case when it first started having start issue that’s what I thought ignition switch so I changed it but now I’m having the problem worst after 1 year later , I took the car in the shop and they said it’s the electronic immobilizer. They said that’s what triggers the car to start . My battery is good .

 

If you have a manual transmission it could be the clutch stop that’s causing the issue.


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