What is a Ambient temp sensor

Can someone tell me what a Ambient temp sensor is and what does it do ? thanks for any info

The ambient temperature sensor is a variable resistor that measures any changes in a predetermined amount of voltage that passes along it caused by changes in the outside air temperature density. The density of the air surrounding the vehicle which is drawn into the engines intake manifold, through the air intake is very important to the Avy's over all performance, it helps burn the fuel more efficiently. The amount of oxygen in the air varies with different air temperature densities and thus as the sensor senses/reads the average air temperature surrounding the outside of the Avy's engine compartment, it converts and sends this electrical signal through its wiring to the AVy's Body Control Module (BCM). The BCM then uses this information along with information from the Avy's Mass Airflow Sensor (which itself measures the volume or air being drawn into the Avy's engines intake manifold ) to help regulate fuel and air mixture ratios.  The cooler the outside air temperature surrounding the Avy's engine compartment is, the denser the air is and thus the engines capable of is most efficient operation. The warmer it is the less efficient, and thus the importance's of the sensors readings, which are passed along to the Avy's BCM for adjustments. The location of the sensor outside of the engine bay itself is crucial, because the air is always cooler there. The greater importance of the ambient air sensor function alone would be noticed while the the AVy is first warming up and then while it is idling. I hope this info helps..........03WD

Hey thanks 03wd maybe that is my problem since it runs rough at idle and at a stop light like it has a power surge, about ready to die, since i changed just about everything else, dont think it the intake gaskets because i sprayed and on differance made to the engine thanks again

Hmmmmmmmmmmmmmmmmmmmmmm. Are you getting any DIC codes you may have, current ones or any stored ones that might hint to an underlying issue. Check those out 1st. Not that all issues are always caught and recorded, by the BCM and sent as a check engine light or DIC warning.  Is your air filter, and fuel filter clean and free of obstructions? If they are, I would then check for loose, unconnected or damaged vaccum hoses, clean the Mass Airflow Sensor and the interior of the throttle body, including both sides and the edges of the throttle/butterfly plate. There are separate spray cleaners available for those items and tasks.

Have you used any type of fuel system/injector cleaners recently? A dirty or damaged fuel injector pulsing incorrectly could be an issue. A faulty fuel pump delivering inadequate amounts of fuel pressure could be a culprit. You may need to have those electrical readings checked. I would also check the connections for and then test the Throttle Position Sensor, and Engine Crankshaft Position Sensor. If nothing more than preventive maintenance. Be sure and unplug , and clean those connections with an electrical parts cleaner. Make sure they are clean at the contact points/pins and receivers. Moisture and corrosion can play havoc on these and your ability tracing the causes and effects. Be sure these connection points are dry inside and out before reconnections are made. Check any ground connections to the body or frame common to these sensors circuits too.


I would also check the connections and fuctions of the engine temperature switch sensor. This little bugger plays a very large role in engine performance, including the idling circuit. Good Luck.03WD

crappy idle is usualy a vacume leak, not allways ......

Measures ambient temperature.