6 is the throttle body going bad, 18 is one or both the camshaft adjuster on the front of the engine are bad you can test them with a multimeter but i forgot what the resistance should be, 26 is the transmission going bad, normally felt as a hard shift from time to time right around 30-35mph.

 

Faults are there to tell you there is a problem somewere but sometimes you just cancel them depends what they are of course ,check out our friend NubyOz that made an easy to understand video about how to get rid of those codes . :thumbsup:

 

Faults are there to tell you there is a problem somewere but sometimes you just cancel them depends what they are of course ,check out our friend NubyOz that made an easy to understand video about how to get rid of those codes . :thumbsup:
Mercedes W140 read and Reset Error codes - YouTube

This is why I love Benzworld.org! Thanks Merc s500 & slowhands. I really appreciate your feedback my friends. My s420 was sitting in the garage for a few months because of some problems it was having. When I decided to work on it, these codes are what came up when I utilized the on-board blink code reader. After resetting the error codes, now I'm only getting code 26. Took it to an indie MB shop & they said that it's a neutral lock out switch gone bad.
Does this sound like a correct diagnosis to you guys? Let me know your thoughts...and again "Major Thanks" for your assistance. I'll be looking forward to hearing from you again

 

i also have code 26 active and haven't figured out exactly what it is, if you figure it out please let me know.

 

That code 26 is within this post below but i dont know if it is or has anything to do with the blinking tool however by doing a simple search on the forum ,almost everything asosciated seams to turn towards the same error code description.:thumbsup:
E0 26 Left heater core temperature sensor (B10/2), open or short circuit *)

http://www.benzworld.org/forums/w14.../forums/w140-s-class/1198136-windshield-demister-seems-blocked-need-advice.html

Check this link out as well ,near the middle are the earlier Merc's .
http://www.scribd.com/doc/32288978/Mercedes-Benz-Fault-Code-Manual

 

Here is another link with good info , check down the bottom were it says "Click here" for the codes description .I'm pretty sure this is for the blinking codes,dont forget the extra link i added to the above post :thumbsup:
K6JRF Auto Page

 

The error code linked above about the heater core isn't the same thing. That is for the AC diagnostics using the climate control display.

For your error "blink" codes, are you using the built in LED blinker or did you buy/make a homemade one like in the YouTube video above?

If you got the code using a homemade unit, you will have to determine which module the blinks are coming from, which is determined by the pin its plugged into.

Seems like you're using the built in one and I think that means the code 26 is "Upshift delay switchover valve, open/short circuit"