starter lock out relay mercedes a140 W-168 - what is its purpose - bypass possible

[MRSSPOCK]

I am working at a friends Mercedes A140 W-168.

I think the fault, (which causes intermittent starting problems), might be something to do with the starter lock out relay.

I haven't got it removed yet for inspection, so I am not totally sure just yet.

I'm curious does anyone know the implications of simply bypassing this relay, if this part of the circuit is causing the problems?

I'm assuming this relay gets energised once the immobiliser has recognised the key as being the correct key for the car?

If I find the relay itself is faulty I will gladly put in a new one, but if it is something upstream which isn't providing the power to energise this lock out relay, then I am considering just removing it completely and fitting a jumper wire.

This car has only a short time to live so it doesn't warrant spending any money on it.

If the repair costs over £100 the owner is going to scrap it.

I just wonder is there a downside to doing this jumper solution? (Forget about the insurance become invalid if the immobiliser is bypassed).

I believe this lock out relay simply interrupts the main solenoid circuit to the starter motor.

I can't think of any downside to doing this jumper modification, but thought I would ask here in case I've overlooked something.

Thanks

 

[MRSSPOCK]

UPDATE:

She's for the bin!

It turns out it is the type with the immobiliser built into the starter motor, so it is virually an engine out job to get at the starter, and then some hundreds of pounds after that for the replacememnt starter motor.

I have to say I hate having to dump something which would be perfectly functional with the addition of a 25mm of wire and two blobs of solder.

So much for the age of recycling and global welfare.

 

[itsmoked]

Interesting. I hear you too.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Check the hood switch and the trunk or lift gate switches.
This may be part of the circuit that inhibits remote starting if the hood is open.
It's a long shot but worth a look.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[dgallup]

Good point, my pickup won't remote start with the hood open, doors too.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[MRSSPOCK]

Thanks for your suggestions.

Unfortunately with the intermittence of the problem, it's difficult to determine if such hood or trunk switching issue is the culprit.

The owner doesn't want to run the risk of getting stranded somewhere so has decided to scrap it.

I did find this link which seems to be quite relevant.

http://www.benzworld.org/forums/w168-class/1708271-starter-built-immobilizer.html

P.S. I have a sneaky suspicion it is possibly something to do with an expansion / contraction issue, because different users have said there fault seemed to occur more frequently at low temperatures, as was the case with this particular car. My immediate thought was a faulty battery, but I'm afraid I was too eager to buy a battery. The brand new battery didn't help at all.