What happened to the Air Temp Sensor on my M103? - PeachParts Mercedes-Benz Forum

Cal Learner · #1 02-12-2009, 03:40 PM

Never noticed this before, but on my 1988 260E there's supposed to be an air temperature sensor fitted into the intake air duct just forward of where the duct joins the air cleaner. According to the service manual, this was added as a production change beginning in the 1986 model year, so it should be there. In the pic below, all that's there is a little round button cap covering the hole where the sensor should go, with no electrical wires coming off it, so it can't be a sensor. The motor runs great, but how is that possible if the ECU is not getting any signal from the ATS? I've tried removing the button cap, but it's stubborn. Anyone know how to remove it? Twist? Pry? Once off, I suppose I can fit a new ATS in the hole and find the wires buried under the air cleaner somewhere, right? Would anything else be required to bring it into spec? The service manual doesn't give much detail. TIA

mbdoc · #2 02-12-2009, 04:41 PM

On a 1988 model there wasn't a sensor UNLESS it was a California version.

Ivanerrol · #3 02-12-2009, 08:57 PM

Different markets - different specs.

My 1988 190e 2.6 with no cat has this sensor.
My 1989 W124 260e with cat does not have this sensor.

Cooler climate spec perhaps?

cliffmac · #4 02-12-2009, 10:19 PM

on a 1990 300te there is this sensor, right where you describe, looks like a diode almost. I think it's virtually the same part that is employed to tell you what the the outside temputure is on the dash. Mine was not engaged in the intake when I bought the car, it was laying down on the intake side. I found it and reinstalled it and it didn't make any difference as to the engine performance, but nevertheless, I don't like that kind of stuff. I think it has more to do with warm weather than in the cold months.