Car is a 1995 855 T5 W 260k miles

Few weeks ago the check engine light came on..this car has the on board diagnostics..and reading the codes off of the black boxes i got 1-2-2 Ambient temp. something or other..so i tried to clear it but it would not..i could read the code..twice but then after the long 7sec hold..the led did not go on..so i removed the ECU..for a week (went out of town) came back and the check engine light was off...but to no avail..as it came right back and still wont clear..what gives?

I sold my 854T a couple of years ago, so I cannot say if a temp sensor is in the air cleaner. I know that there is one on the NA cars.

The temp sensor on your bumper sounds like it is working.

Klaus
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Proud owner of a 1967 220S

Is this the same sensor located up front down on the opening of the bumper? my dash temp display is still working and seems acurate.

That didn't happen on my 854T. I believe that the dash temp comes from the air intake sensor under the windshield.

My 1998 had 2 temp sensors, one in the driver's side grill, the other hanging down on the passenger side.

Just unplug the temp sensor in the grill and see if that is the one. A probe with a multimate should show resistance around 2-300 ohms.

Klaus
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Proud owner of a 1967 220S

Yep..i saw 500Ohms on the sensor in front of the intercooler at about 70 degrees and i could get it to fluctuate the resistance by warming it up and then blowing on it to cool it down..i blew some air into the connector hopping it was just making bad connections or something..

The A-2 1-2-2 = intake air temperature sensor signal missing. Without knowing what the intake temperature is, the ECU will run at default mode to determine the proper fuel/air mix.

Check the wiring at the plug before ordering a new sensor.

Klaus
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Proud owner of a 1967 220S