E300 - unauthorized start when cold - PeachParts Mercedes-Benz Forum

slowmoe · #1 02-14-2004, 02:47 PM

It has been a long journey to get to this point. But, I have finally found that my car is not recognizing any of my keys when I try to start it on cold mornings.

Both the red and the green lights on the rear view mirror will flash alternately, the car will crank - but not start. The only code I get it "p1617" It relates to the control module. The module was replaced but the problem resists.

Since, this is happening with all the keys, I am assuming the the problem lies on the recieving end of things.

Can anyone offer some advise?

slowmoe · #2 02-15-2004, 11:09 AM

Anyone?

This page is my last resort. The dealership even said that they have no idea...

shoe · #3 02-15-2004, 12:57 PM

Dan have you tried disconnecting the battery for a few minutes, then attempt starting wth one of the manual key's? I cannot imagine what difference it would make but may be worth a try.

shoe · #4 02-15-2004, 01:02 PM

Dan you may want to try this site http://www.startekinfo.com/StarTek/ I have printed out a lot of info from this site. it is official MB. You may be able to get the wiring schematics you need for the remote key circuits. It is kinda pricey at $20.00 per 24hr period but if it gives what you need it would be cheap.

slowmoe · #5 02-15-2004, 01:04 PM

Keith, thanks for hanging in here with me!!!

That's an interesting thought....

I did disconect the battery a few weeks ago when I thought it might be a battery charge issue. It was out for about 30 minutes - Pep boys and back - the problem continued after that. I might just try it again for kicks.

By "manual" key are you refering to the non-switchblade type. If so, the answere is, yes I have tried it - but not directly after dis/re connecting the battery.

shoe · #6 02-15-2004, 01:15 PM

Yes, the non-switchblade key. When I bought my car from Benzmac he only had one of the switchblade key's so since my wife drives the car most of the time she uses that one. I thought I would be missing something by not having the capabilities of the remote key however, since it is so bulky I have not missed a thing. And given the problems you are having now with yours I'm kinda glad I open my doors the old fashioned way

Paulwho · #7 02-15-2004, 09:16 PM

slowmoe,
Was the replaced module the IRCL or the ME/HFM fuel computer?

I am working from memory but the IRCL sends a signal to the ME and the ME must release the progaram to allow the car the start. 90% key related, but not when all keys act the same. 9% IRCL (module behind the instrument cluster) 1% Fuel computer. The diagnostics on this inbetween protection system are very scary.
I will check this info after I return following the Presidents Holiday.

KenP · #8 02-16-2004, 07:40 AM

According to documentation I have, there are several possibilities listed under:

"Motor does not start. red/green lamps blink alternately with ignition on"

Possibilities are:
1. Vehicle is Locked (incorrect use)
2. Vehicle will not unlock
3. Engine Control Module did not authorize DAS (Driver Authorization System)
4. CAN wiring harness defect
5. Engine control module has not learned the identification code
6. Defect in engine control module

Troubleshooting described in literature is pretty straightforward, but you need a Mercedes HHT to track the flow chart. Not sure why the dealer is waving you off on this... there's a troubleshooting section devoted to this and there are only about 6 steps.

Seeing as how the problem only occurs when its cold, there's an intermittent somewhere... I'd start by doing the simple stuff... unplug and reconnect all the connectors in the system... you may simply have an oxidized socket connection somewhere.

If that doesn't work, you'll need to find a dealer/tech that will take the time to look it up and do the procedure while the system is in the "failed" mode... which I suspect will mean hooking up the HHT in a cold parking lot ...

Hope this helps.

slowmoe · #9 02-16-2004, 08:34 AM

Wow, now that is the kind of information I was looking for!!!!

Paulwho, the module that was replaced was the "control module for the fuel injection system" I am not sure if this is the module IRCL or the ME/HFM fuel computer - just not all that familiar with the terminology.

KenP,

1 or 2: I am pretty sure that it is not this unless the car thinks that it is still locked....

3 and 5: If this is refering to the control module for the fuel injection, my indy who replaced it with a new one says that it is coded. I guess it still can be this if he coded it incorrectly. Is there anyway to verify???

4: Possibility

6: Same as 3 and 5 above unless we are talking about diferent modules.

I like your recommendation to check all of the connections in the system. How do I get a diagram?

KenP · #10 02-16-2004, 02:52 PM

Unfortunately, I don't have the wiring diagrams for your car... but, the IR/DAS system doesn't have that many components (although they are complex) so, not sure a wiring diagram will help.
Seems to me (may be wrong) that if the IR remote is unlocking all the doors properly, and the alarm is not going off when you open the door, that the system knows the car is unlocked... so, the numerous door switches are probably OK.
When you attempt to start the car, the Engine Control Module generates a random number which is sent to the IRCL module. The ECM uses this random number combined with a code number to calculate an authorization number. At the same time, the IRCL makes the same calculation with the same numbers. The IRCL sends the authorization number to the ECM where a comparision is made. If they match (meaning the codes match) the start is "authorized" and the fuel injection management function is enabled. The ECM then communicates back to the IRCL that the start was authorized. IF the start is not authorized, the fuel injection system is not enabled, the IRCL gets a "no start" signal, and the red/green lights flash alternately.
I think this is where your system is failing... so, I'd carefully check the engine control module and the IRCL connections.
On the MY96 E class, the IRCL is supposed to be under the floor panel on the passenger side. I've attached a pix.
I don't have an E, so this is all strictly from the literature that is available to me... but, its worth a try.
IF the IRCL is failing internally due to cold temps, you could test for this by leaving the IRCL exposed until it fails and then warm it with a hair dryer... if it then starts after warming, you've found your culprit.
Hope this helps.