LED Blink code tester HELP!

[vtechnician]

I have the following problem on a w124 220E with a 111 motor:
I am having trouble getting codes on pin 8,when I press the switch for 4 seconds,the light comes on and after I leave it, no flashes/codes.
I even unplugged the water temp sensor,no1 injector,MAF sensor and still no codes.
However,I do get codes on pin 6 and pin7.Everytime I unplugged something on the motor electronics,I re-checked pins 6,7 and 8 and there are no new codes.
I cannot delete any codes as well.
I have not used an LED but a minature interior globe to build the tester.

Any ideas?

 

[vtechnician]

Problem solved.I used an LED with a 1k ohm resistor.
It works great now. Got four error codes from pin 8 and deleted them.

 

[nick4u1]

I remember having the same issue, it took me a while to figure out to do that.