1. the problem is intermittent. i will send you the service information update later from my office. am not sure if your chassis number is included, but i'll check.

2. you can still start the car even with the doors locked. for safety reasons, some people lock the car while they are sitting inside without the key in the ignition... and use the re-heat function on the aircon during winter. then they will put the key on the ignition and start the car. the interior motion sensor recognise this.
another reason was that the transponder recognise your key as "valid". even if your key got no battery at all!
you can try it. lock the door and start the car. maybe i am wrong too.

the starter lock-out is not included on the wiring diagram i previously post for you. i will post it with location next time.
it can be diagnosed from the transmission contol unit.

 

Thanks for the reply Sleepwalker,

It is really frustrating to spend so much on parts that not meant to be purchased!

Anyway, I was refering to some similar posts from the other forums;

1. Some people were talking about the replacement of an
a. over voltage protection relay
or
b. crank shaft sensor

2. If the charging of the alternator is always fluctuating (sometimes the charging may be normal while other times it could be low), could it cause these failures to start?

3. I have notice from the readings from the ECM to the IFZ was 119.6 amperes (the range
of transfer suppose to be between 115 to 129 amps i think, but anyway it is still a sufficient rate)

 

your car is a new version where the over voltage protection relay was eliminated.
crankshaft sensor will surely cause this kind of problem as well... but it will register as a fault on the ECM memory.

during starting, everything depends on the battery for power supply. i believe you have replaced the voltage regulator already. defective battery will show some tell-tale signs if you are driving the car.
the charging is always regulated, because if it's not... two things will happen. the battery will either go flat or boils... acid level will be down, and will go flat as well.

as i have repost, it's been concluded that between IFZ and ECM, the signal is fine.

i think others who reads this topic must be going nuts by now. but this is where we analyze the problem with very limited resources. mine... never seen the car; yours... wondering what it might be.

 

Ok, the above has never happened before so therefore, the alternator's charging is fine.

Will be waiting for your post...

I sincerely apologise to everyone who are going nuts or being confused, including sleepwalker but I really appreciate your patience and tolerance in giving me so much help and education in W202s technical side.

The starter lock-out & crankshaft sensor, I shall be asking the technician to have a look at these items! Will keep you updated.

 

Hey Sleepwalker,

1. The dealer called up and still haven't found the cause of the intermittent starting failures problem but they concluded that the problem was a "one off" problem after the new IFZ control module was installed.

2. Crankshaft Sensor – They advised that if the crankshaft sensor is faulty, it will cause misfirings when the car is idle or when driving?

3. Starter lockout relay module – They say this module’s function is only to detect whether the car is in a driving mode or idle mode?

Any comments?

 

this was my very first response, and i assume it has been checked and done.

the starter lock-out module is to give a go signal for the starter to turn...if the authorization is valid and shift lever is in P or N.

i still want to know the problem.

1). does the starter turns when you start the car and cut's off after about 5 seconds?

2). or the starter doesn't crank at all?

3). and you can hear a "click..click" sound instead?

4). or the engine would fire-up and stop immediately?

5). or you start the car, but no response at all?

gosh... i wish i can have my hand on it for just half a minute. i am running out of imagination.
i have a good feeling but, cannot apply now

 

Yes it turns and it did not cut off, just the flashing lights and cranking

yes, it cranks

No click click sound

after a few minutes, it would fire up and would run as normal

See answer for no. 2

Where is the flywheel located? Is it near the ECU or IFZ Control module?

 

the flywheel is on the rearmost part of the engine. this is where the transmission is connected via torque converter. this also got ring gear on its edge that makes contact with the starter motor.

on the upper part of the flywheel cover (an engine bell housing) is where the crankshaft position sensor is located.

it is possible for the CPS to be faulty, but some tell-tale signs contradicts it such as: the flashing of LED on the mirror and the fault code which is not present.
it's just so un-convincing.

to others who are reading this post, please share us your coments and analysis too. we are plunging down the abyss.

 

Yes it turns and it did not cut off, just the flashing lights and cranking

[quote]

this eliminates the starter lock-out as suspect.

 

I'm having trouble deactivating security for my 1996 Mercedes S320. When I put the key in ignition, engine cranks but car wouldn't start, and red and green security lights on the rear view mirror start flashing.
It started when I lost my remote key and I tried to open with other remote. I opened the car with out remote and tried to start the car. Car won't start, I thought its not starting because last time I locked the car with remote so I bought some new batteries and put them in the other remote unit, I synchronized and locked and unlocked the car with that and tried to start the car and I found it locks and unlocks the car but it won't start the engine. In the mean time I found my old remote key that I would always use, I tried to start the car with old key but this time it won't start with them either.
I did pretty much every thing, I tried to lock and unlock from the driver door and from the trunk and then tried to start the car, it did not help. I even removed the positive terminal form the battery for almost 3 days, I thought it might remove the security codes and then tried to start after 3 days and could not start the car. Can you please help me in this situation