Hello all, I have a 01 s430. The A/C off light came on a bit ago. Checked all fuses and all we good. Checked pressures and all were good. Off to the shop for the code reset Which Did turn the light off and compressor back on. The code that came up was for the ETR Valve B1256. My question is, if the light returns which means most likley the ETR valve is bad, where is it located and how easy is it to replace??

 

update #1....after about 30mins the light has come back....time to change the sensor...I'll let you know after that what happens.

 

Hi,

Have you found a solution? I have the same problem on my -01 S320 Cdi.

Refilled system and it works fine for about half an hour then the red light comes on again on EC. I have checked everything and all is well, also in secret menu. System and compressor works fine when I give "jump current" to magnet...........

Mercedes not able to find fault (yet).......

 

turned out to be a bad compre[:'(]ssor.....crap! $1900 and I'm back on the road.