Battery drain 1,5 Amps Terminal 87

[124500E]

Hello,

my 500E has a small electrical issue. If I connect the battery the fuel pump immediately starts to pump. Also the car has a current of 1,5 Amps. I located the drain in the module box and the fuses 1,2 and 4 on the GM module are always hot. The terminal 87 is hot and this is where my drain is.

I understand the system that the GM get the Terminal 15 from the ignition switch and switch on the terminal 87. Is this right ?
I checked the terminal 15 at the GM (Pin 34) and the voltage is at it should be.

Does anybody ever had a problem like that?

Thank you!

 

[gsxr]

Sounds like your 38-pin diagnostic socket might be the problem. Read the thread linked below. Also see if the problem goes away if you remove the LH module and/or GM.

HOW-TO: Replacing the 38-pin Diagnostic Socket (X11/4) | "HOW-TO" Tutorial Articles

When I recently purchased my 500E it had a crippling Battery Drain which would totally drain it overnight. Removing all of the Fuses & Relays did not eliminate the parasitic drain. I did discover that the LH module was causing the current draw as it was not shutting down when it should be. As...

www.500eboard.co

 

[124500E]

Hi,

seems really plausible because as I bought the car the cap of the diagnostic socket was missing and the hole was just covered with tape. I will check an let you know

 

[nocfn]

I bet those wires are full of corrosion in the 34 38 pin socket underneath.

 

[124500E]

What socket do you mean? A socket from a ECU?

 

[LWB250]

What socket do you mean? A socket from a ECU?

The 38 pin diagnostic socket that is a part of the box that contains the ECUs. There is a circular cover on the box that allows you to access the socket with a plug for the handheld tester or SDS/DAS system.

Dan

 

[124500E]

Hi, yes that’s the socket we are talking about. I guess the 34 pin socket from nocfn should be the 38 pin

 

[gsxr]

Click the link in post #2. There are many pretty photographs. And a very detailed description of the power flow.

 

[nocfn]

Sorry yes, the diagnostic socket, it has far less pins than the number of holes.

 

[124500E]

Hello together,

Take a look.....


Thanks for the advice

 

[gsxr]

Yep, that ain't right... fix the wiring and your issue should go away.

 

[nocfn]

Been told by a wise man that you should buy a new connector. I suppose you can soak the oe unit in a baking soda solution or acid/corrosion remover.

 

[darek_u]

Been told by a wise man that you should buy a new connector. I suppose you can soak the oe unit in a baking soda solution or acid/corrosion remover.

That's what I did - soaked the plastic parts and desoldered pins in weak acid solution overnight. All parts came out brand new looking. After reassembling I sprayed all connectors and inside of the socket with preservation oil for electrical connectors - it's been fine for 2+ years now.

 

[nocfn]

I wish I had the mushroom connector for testing! I also wish MB had some slack in those wires. At some point in the near future, I need to solder new wires for length and pins in a new socket for my dad's E420. Someone before the dealer(member here) got the car, someone started the job but abandoned it. I had the seller just isolate and shield the wires until I can get to it. Perhaps this summer....