[gbalthrop]

Originally Posted by Curtdaflirtjlp

... I currently have the same problem. Starter turns over and clicks but no start...

NOT sure what your Vehicle's Symptoms are exactly. OP's Starter Cranks or turns the engine at 177 RPM, a normal Starter function, but his engine does NOT fire.

In YOUR case, you say "Starter turns over and clicks". I don't understand what is actually happening. If the Starter Solenoid simply "Clicks", that does NOT result in Starter Cranking or Turning the engine.

If you would like help, please (1) clarify what is happening, (2) indicate what Scan Tool or Diagnostic Software you have available, and (3) List Fault Codes in DME, EKP & CAS Modules, so someone can suggest tests to try to isolate the issue.
George

[dpaul]

George;

FWIW

1) the EWS4 system does not use a "revolving code" or often called 'rolling code' like older systems. In EWS4, a 128 bit 'secret code' or SK is written to the DME at the factory. It's in a memory location that cannot be read without proper authorization (i.e. you can't get it with INPA) and it can never be re-written.

An encrypted version of that SK is written in the CAS module. A handshake between DME and CAS at startup compares the two SK entries. If they don't match, the DME prevents the engine from starting by inactivating the injectors.

I believe this is the sequence of events happening at startup:

The key is inserted and CAS reads the transponder in the key

CAS verifies the identity of the key, and if good, enables (not activates) the starter.

The DME generates a random seed and factors the SK with it to calculate a 'request' which is sent to the CAS via the CAN bus.

The CAS uses the request and the SK to to calculate an 'acknowledgement' which is sent back to the DME.

The DME does the same calculation as CAS then compares with it to the 'acknowledgement'. If good, the DME enables fuel injection.

The start button is pressed and off you go.


There is nothing that INPA or ISTA can do to remedy the problem of a mismatched SK. Nor can they successfully encode a new DME or CAS.

To replace the CAS or DME, a repair facility equipped with rather expensive non-factory software will read the SK from the DME, encrypt it and write it to the CAS. This is why DME, CAS and key must be provided to them. A dealer would simply order a new CAS or DME from Germany with the correct SK encoded at the factory. And charge you a small fortune.

2) Importantly, CAS doesn't care or even know of the SK matches or not and lets the starter crank as long as the key is good. In practice, CAS usually sets an error code indicating that the engine has failed to start, typically A0B4.

So the ability to crank but not start is perfectly consistent with an EWS4 fault or a CAS/DME communication failure.

Most likely, the OP has an internal CAS fault.

[gbalthrop]

Thanks for that info. If you know of any BMW Training Manual, ISTA Reference, or other source that offers
any insight into the EWS, how it works, or HOW various faults can affect Cranking or Firing, please advise.
As you can see from my terminology (or lack of it ;-) I'm NOT an electronics professional. I DO try to lookup,
learn, and use correct technical terminology, as I believe "Words Matter" in any kind of communication, particularly technical.

Attached are ISTA ScreenPrints of OP's CAS & DME Modules, showing Black/Violet D_EWS wire between
CAS X13376/20 and DME X60001/15. I presume THAT is the wire used for "Handshake" between CAS & DME?
If NOT, WHAT "Signal" is sent by CAS to DME on that wire? Is it your understanding that the CAS Module
will send a START signal to the Starter Solenoid (KL50) WITHOUT proper "Handshake" from DME?
That results in Starter Cranking but NO firing? As you see from the attached ISTA ScreenPrints,
CAS also Powers the Fuel Injector Relay Electromagnet Coil to send power to the Fuel Injector Connectors.
Any thoughts on whether activation of that EFI Relay is dependent upon Immobilizer "Handshake"?
OP's car is built in 2006, so has the "OLD" E-box setup.

He has two MRS "Undervoltage" Fault Codes: 9408 & 93D0.
Since MRS is powered by CAS KLR, and his KL Diagnosis (INPA) shows extremely low voltage with Key Inserted,
there appears to be some issue with KLR "Terminal". Do you have any idea WHAT internal Fault in CAS might cause that?

Any thoughts on whether a wet or corroded connector, such as X13376 at the CAS Module could cause his issue?
EGS fault CF14 says NO Message from CAS, presumably via PT_CAN.
D35A DSC Fault says No CAS Terminal Status, also presumably via PT_CAN.
All those things taken together, seem to point toward SOME issue with CAS Module OR its Connector.
I don't know enough about electronics generally, or the CAS & Immobilizer function in particular
to be able to suggest anything other than trying to determine if the EFI Relay is being activated,
if the Injectors are being pulsed by the DME, and if there is Spark.

Thanks,
George

[dpaul]

Originally Posted by gbalthrop

Thanks for that info. If you know of any BMW Training Manual, ISTA Reference, or other source that offers
any insight into the EWS, how it works, or HOW various faults can affect Cranking or Firing, please advise.

I have no reference material for EWS4. Most of what I know I've learned from discussion on other forums where DME access for tuning purposes, including EWS bypass, is a focus. Some of it is from inspection of MSS60 program code and CAN bus traffic sniffing.

As unlikely as you seem to find it, a failure of EWS4 authentication between CAS and DME can lead to a crank, no start condition. I've observed this myself in my M3 when attempting to replace the DME. If you simply plug in a similar part without matching the SK, the engine will crank until it times out without starting. Of course, that was an MSS60 DME and S65 engine. I have not tried the same sort of experiment in my 335.


Attached are ISTA ScreenPrints of OP's CAS & DME Modules, showing Black/Violet D_EWS wire between CAS X13376/20 and DME X60001/15. I presume THAT is the wire used for "Handshake" between CAS & DME?

The 'challenge-response' authentification scheme ( a widely used paradigm in computer security), is conducted via CAN bus. But I have no information about what this 'D_EWS' wire does..

As you see from the attached ISTA ScreenPrints, CAS also Powers the Fuel Injector Relay Electromagnet Coil to send power to the Fuel Injector Connectors. Any thoughts on whether activation of that EFI Relay is dependent upon Immobilizer "Handshake"?
That's a good question. My understanding is that the DME is in control of everything about running the engine except powering the starter. So I'd guess no, CAS is going to activate that relay regardless, if the key is good. Just a guess.

He has two MRS "Undervoltage" Fault Codes: 9408 & 93D0.
Since MRS is powered by CAS KLR, and his KL Diagnosis (INPA) shows extremely low voltage with Key Inserted, there appears to be some issue with KLR "Terminal". Do you have any idea WHAT internal Fault in CAS might cause that?
My understanding is that Terminal R is not an actual wire/relay - it's a CAN bus signal originating in CAS. I don't know how this measurement is made but I assume it relies on internal CAS circuitry.

Any thoughts on whether a wet or corroded connector, such as X13376 at the CAS Module could cause his issue? EGS fault CF14 says NO Message from CAS, presumably via PT_CAN. D35A DSC Fault says No CAS Terminal Status, also presumably via PT_CAN. All those things taken together, seem to point toward SOME issue with CAS Module OR its Connector.
Agreed about that conclusion. Bad connector is generally my first goto but there are plenty of recent reports of CAS module failures. Seems it's not that rare, although usually it's a problem of activating Terminal 50 and a failure to crank.

OP: have you cleared all these errors to see which ones re-appear?

[t2rx6]

Originally Posted by dpaul

OP: have you cleared all these errors to see which ones re-appear?

I just did clear everything.
Waiting for my Noid light and ignition coil tester to arrive (thursday) so I figured i'd clear the codes after reading your post.

During the clear I got:
ADR Gen. name JobStatus
01 MRS ERROR_ECU_REQUEST_CORRECTLY_RECEIVED__RESPONSE_PEN DING
6D FAS ERROR_ECU_REQUEST_CORRECTLY_RECEIVED__RESPONSE_PEN DING
92 VIRTSG92 ERROR_ECU_SERVICE_NOT_SUPPORTED

Not sure if that's an issue everything else got OKAY.

I turned off the car and then turned it on to start it again and the error log (which had said no error stored post clearing the memory) now has 2 codes stored:
29 DSC OKAY 1 Error stored 5EBA E0

40 CAS OKAY 1 Error stored A10A 2

Also @george in the process of checking all this prior to posting here I actually checked all those fuses in the engine bay as well already.
Still want to check for the spark during cranking to be sure though.

There's a few places around me that say they fix BMWs (specialize even). If I have to take it somewhere for this CAS module i'll probably take it there before I take it to the dealership.
I guess before I take it though i'd want to call and ask if they can address CAS related issues?

[dpaul]

Originally Posted by t2rx6

I just did clear everything.
Waiting for my Noid light and ignition coil tester to arrive (thursday) so I figured i'd clear the codes after reading your post.

During the clear I got:
ADR Gen. name JobStatus
01 MRS ERROR_ECU_REQUEST_CORRECTLY_RECEIVED__RESPONSE_PEN DING
6D FAS ERROR_ECU_REQUEST_CORRECTLY_RECEIVED__RESPONSE_PEN DING
92 VIRTSG92 ERROR_ECU_SERVICE_NOT_SUPPORTED

Not sure if that's an issue everything else got OKAY.

I turned off the car and then turned it on to start it again and the error log (which had said no error stored post clearing the memory) now has 2 codes stored:
29 DSC OKAY 1 Error stored 5EBA E0

40 CAS OKAY 1 Error stored A10A 2

Also @george in the process of checking all this prior to posting here I actually checked all those fuses in the engine bay as well already.
Still want to check for the spark during cranking to be sure though.

There's a few places around me that say they fix BMWs (specialize even). If I have to take it somewhere for this CAS module i'll probably take it there before I take it to the dealership.
I guess before I take it though i'd want to call and ask if they can address CAS related issues?

Ok, that tells the tale. The DSC error is not significant - it would likely go away with a little driving.

So the only error you have is A10A, which is "EWS4 timing challenge / response error". I think 'timing' is probably hold over nomenclature from EWS2/3 days but the challenge/response is exactly what we've been talking about. Your CAS and DME cannot successfully authenticate the SK so the engine cranks but won't start.

Yes, call the indie and ask specifically if they can program SK and key data to a new or used CAS that either you or they source. There are also plenty of services you can find on-line where you can send CAS,DME and key for testing and service.

BUT it is possible that this is a connector issue, as George suggested. I'd pull the CAS, take a look at the pins, spray some contact cleaner and do the same at the DME. Not difficult and costs nothing.

[t2rx6]

Well I didn't want to keep all of you guys in suspense but I went through everything we checked here so I finally gave up.

It took longer than anticipated to get the car from my house to someone who could address it (none of the BMW service places that weren't the dealer called me back!).
I finally broke down and took it to BMW which they replaced the battery (My battery wasn't holding a charge as long as it should have anyway so I was fine with it) and reprogrammed the CAS system. Works fine now.. Hooray!

They also found a handful of things they wanted to do that were WAAAAAY to expensive given the price of the parts and the labor involved (100% confident I can do all these things myself over the weekend).
At least she's back running again!

Thanks everyone who tried to help me!

[Hclark]

Was there ever a resolution to this problem? Same issue, all of a sudden on 2011 328i xdrive.

[TyroneShoelaces]

Originally Posted by Hclark

Was there ever a resolution to this problem? Same issue, all of a sudden on 2011 328i xdrive.

yes literally the post above yours. OP came back and updated his thread which was awesome.

Battery and "reprogrammed" the CAS he stated done by the dealer. whatever reprogrammed means. Factory code?

[Elianne205]

So the only way to do it is with the dealer? I have the same issue but the closest dealer is 5 hrs away and really not looking forward to see how much it will cost.