hello, I’ve already looked up a little here. but the answer that suits me isn’t found yet. drive a 99 c70, with 121 kw (sucker) and 108,000 km. my problem: the glow bulb in the armature board “motor control” has started. so after several turns on and off the motor (sucker was always on) I left the workshop. there and the bulb (showing effect) stayed out. then I had the control unit read out. result – statement workshop: lambda-sonde defective. would not have measured at the sound and this reacted well. second and third alternative (workshop): cable or even the control unit. what would it be? if the sonde is defective, what would cost me and how long does i.d.r. take such a thing? I don’t have anything related to air mass meter defects here again. (???) I’ve had the problem for several thousand km already, that in the empty loop needle of 900 would like to know about it.