[spanaz1]

what is wrong here? a key ? PS I checked the LED when I press any button on key it light but no response from car

[mexanico1971]

what is wrong here? a key ? PS I checked the LED when I press any button on key it light but no response from car

Hi
I have similar situation in one w202
The car dont unlock doors and not turn EIS , after a swap battery and remote fall in the ground !
I ckeck and re-solder remote " big key " and still no life in car , remote are blinking the Led good.
I try to program it , but no luck .
All fuses are ok
Any ideia ?

[Martin1234]

do you know which of the 2 chips (4j74y) has the eis part number store it in 2003 R230
thanks

[dave11674]

ok to bring this thread back to life
i work mainly on Sprinter W906

i believe all mercedes are the same in this next manner
if the key is not being picked up when inserted
IE..
you do not hear the ESL buzz and dash lights come on after turning
your LED test key does not illuminate

then
open the module and test the reader coils
3 pin
center pin - COMMON
outer pins in ohms mode you should get 1.2-1.5 ohms on a GOOD coil
if you get nothing across one or both then its possible you may have a broken wire winding.
on this and most mercedes key coils the wraps are 20 per section.
so the 3 pin header as mentioned before
top pin nearest the coils (W906) is for the outer most windings
wrap it 20 times and then channel the wire down to the center pin, wrap it round this a few times 
then back down the channel and do 20 more windings on the inner groove.
then back down the channel onto the final pin, wrap it round a few times
then heat the copper enamel coated wire so it tins and solders to the pins
you should now have 1.5ohms on the windings.

BUT
its not always this.
sometimes the MCU (9s12) could be faulty
mine on the bench as we speak has 2 x CAN bus faults

Establishing a diagnostic session with the selected unit ....
Diagnostic channel is open.
 

  --- electronic control unit identification ---

Mercedes-Benz No.  : 9069003901
ECU Origin        : DCS
Supplier          : Marquardt
Hardware Version  : 07 / 28
Software Version  : 11 / 28


Fault Codes
============================================
9009 Interior CAN bus : CAN-high line has Short circuit to ground.
9007 Interior CAN bus : CAN-high line has Open circuit.
9005 Communication fault with control unit N26/5 (Electric steering lock control module) or TERMINAL 30 NOT Present



as you can see i can still communicate OBD on the bench with the EIS/EZS

but i have this CAN bus fault and i cannot get it to detect a key inserted...

as you can see from my pics there is 5 x ic's on this version of EIS

1 x main mcu 9s12
2 x nxp tja1041at - high speed can transceiver
1 x atmel ata5743p6 - RF receiver
1 x mc33989peg - System Basis Chip with High Speed CAN Transceiver

i have lots of W906 eis with a full range of faults
i may try swapping ic's about to see where i get.

hope this post also helps other people

dave