Hi all, I am new in this forum and I hope I would be able to get help from you guys here.

I have trouble starting my 1995 W202 C280. On occasions, the engine could not be started but instead the cranking sound from the engine could be heard and both the infrared lights (red & green) on the rear view mirror will start to flash alternatively. There are power coming through the car though the lights, stereo etc are working. I have to keep turning the ignition and the sound of the cranking keeps occurring. Eventually I gave up and took out the key and waited in the car for about 2-5 minutes and then the car would start up back to normal as if nothing had happened.

This problem doesn’t happen all the time but happens unexpectedly, say that I’m going to the bank or restaurant for 10 mins and return back to the car and this starting problem will occur; leaving me to wait in the car for 5 mins before it could start again.

Anyone has encountered this problem in their 1995 C280 W202? I have replaced:
- New keys
- New car battery
- A voltage regulator (for the alternator)
- IFZ Control Module

I have done these replacements and the problem still occurs! This has been going on for 7 months now ever since I had installed a new ECU. The MB dealer don't even know what is the cause.

I would really appreciate any comments from you guys?

This is the result i got the the readings in the HTT .

Any ideas?

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have you replaced the batteries in the electronic key? have seen this problem before and is usually flat batteries or dead key. try using your spare key for a while this may help to diagnose if its a key fault.

Yes I have done that, even to all my existing keys. But this only apply when both lights (red & green) are flashing at the same time.

Mine existing problem has both lights flashing alternately....... and the engine could only crank...

when you have both lights flashing alternately and the engine is cranking but wont fire it means that eng control unit has either wrong or no can signal from Ifz. basically your key is coded to the Ifz control unit and when you put your key in the ignition the Ifz receives that code and verifies it, if it is a matched code the Ifz will permit the engine control unit to function, this signal is sent via the can data bus. i have found that sometimes if you turn the key too fast it will create this exact problem, I assume the coded key cant react fast enough hence Ifz sends no can signal to eng control unit and you get locked out for X amount of time. try turning the key slower to allow for all that data to be processed.

Thank you so much for your input Ozzy!

Your feedback is one of the most convincing ones I had for these 4 months!

So when the lights flash alternately, it means the ECU has no/wrong signal from the IFZ? Because I have recently replaced the IFZ Control Module and it didn't seem to help.

As of yesterday, the MB dealer has re-ordered a (coded) new key and new (coded) IFZ control module again for a another trial/test.

Apprieciating and awaiting your comments..

Hi good day
I m having problem with this 1995 C280 intermittent wont start n no trouble code.. Infra red key battery replaced n working fine, rear mirror unlock with IR remote with green light n lock with red light flashing, engine control unit. Cam sensor, Crank sensor replace but still most of the time wont start.. but some time if it start car can run for whole day without problem but key off n try start again mostly wont start again..
getting no where to fix this MB.. really need ur help,,
Thanks from
Ricky