ambient air temp sensor fault

**monty2000** · 7th February 2011, 21:54

for the last six months ive been havig probs with my engine management light coming on intermitently. (car with spanner through it). on ignition. (dissapears on start up).
My mate has reset it 3 times for me now. My temp reads fine at all times. ive read up the ambient air temp sensor is the outside temp reader which is displayed on the dash. why would this throw an engine management issue??
ive had a look but cant find anything on this issue.
is it w???orth changing it or maybed giving the electrical connectors a good clean.

**gtr1000** · 7th February 2011, 22:21

I'd say that the fault you're getting is the ambient air temp being measured by the MAF sensor, ie. the air temp being drawn into the engine, not the sensor that measures the air temp that's displayed on the dash as the "outside air temp".

Cleaning the MAF sensor might get rid of the problem.

Went through exactly what you've described and replaced two "good" air temp sensors, the ones in the bottom grille beneath the bumper. I then twigged it was the MAF sensor, cleaned it and all was good for 12 months. Spanner light came back, so cleaned it again.

Have you noticed a drop in mpg?

**monty2000** · 7th February 2011, 22:30

Originally Posted by gtr1000

I'd say that the fault you're getting is the ambient air temp being measured by the MAF sensor, ie. the air temp being drawn into the engine, not the sensor that measures the air temp that's displayed on the dash as the "outside air temp".

Cleaning the MAF sensor might get rid of the problem.

Went through exactly what you've described and replaced two "good" air temp sensors, the ones in the bottom grille beneath the bumper. I then twigged it was the MAF sensor, cleaned it and all was good for 12 months. Spanner light came back, so cleaned it again.

Have you noticed a drop in mpg?

i dont really know mate. as i dont have onboard computer (mpg calculator thingy). since ive had it i have really thought its been pretty crap on juice.good if drivig very slow. but on average no better than my 1.8 16v ecotec petrol astra. always put it down to the turbo. could u provide any links on the cleaning process please?