W202 no interior lights or immobiliser function on mirror

[MickHarro]

Hi all
New to this page
Have several Mercedes cars W126. & w202
The W202 C200 Auto Elegance 240,000 kms is my current problem
I’ll try and keep this short but need to explain what I be done
Purchased the car with it stuck in limp mode ABS light on the dash It would start stop drive ok
I got a 38 pin reader to read the led flashes to see what was going on
Plugged this in as per instructions
Won’t read any codes off any pins
No light at all after you energise it
Next to this plug are fuses that looked a little corroded so I replaced them
Not thinking at the time ( clearly) I unplugged the 2 connectors of the module behind these fuses to check for corrosion without disconnecting the battery
Stupid thing to do I know
Anyway plugged it all back in
Now the central locking won’t work at all
No lights on the mirror and I can’t reset off the key
Key is working
Car will crank but not start
Clearly Ive fried something
Not sure where to look other than checking all the fuses I can see
Would appreciate some guidance
Don’t worry I’ve already kicked my own butt

cheers

 

[mattkh]

Any idea which module you unplugged..? Were the 2 plugs connected to the same module from what you can see..?
Can you hear the fuel pump priming when you turn the ignition ON..?

 

[MickHarro]

Any idea which module you unplugged..? Were the 2 plugs connected to the same module from what you can see..?
Can you hear the fuel pump priming when you turn the ignition ON..?

Hi
I unplugged the one directly behind the fuses on the passenger side the one with the metal tab locks It’s a silver case
Yes unplugged both connectors from this one unit and nothing else

yes can hear the fuel pump priming

Hope this helps

 

[mattkh]

If you feel brave enough, disconnect the battery for a few minutes, as for a reset. Then connect and test.

 

[MickHarro]

Ok
Shall do tonight after work
I’ll let you know how I go

cheers

 

[MickHarro]

Hmm
Very interesting
Just went to disconnect the battery as you suggested
It was dead flat .1 of a volt
I had charged it 2 days ago as I’d been cranking it a fair bit prior to charging
Back on the charger now
I’ll swap a good battery out of my W126 tomorrow in the daylight
Just to try
A current draw possibly
Only thing open was the bonnet
Cheers
Michael

 

[MickHarro]

Well
After the my spare battery going dead flat
I’ve now put the good battery out of my W126 in the C200
And the car let me sync the key fob and starts fine and also locks and unlocks again
Looks like problem solved
Thanks again for your help

 

[mattkh]

Looks like problem solved
Thanks again for your help

Excellent news.