Ambient temp sensor

some times after market senders read hotter if there not quiet the same value

Hi Glenn, I'm glad to help! Here's how you check the Ambient Temp Sensor circuit itself to see if its working properly. Disconnect the Ambient Temp Sensor Connector. If the temp reading go to the default mode it will show 40 degrees. If it doesn't go to 40 Degrees then thyere something wrong with the system. Could be wiring or display itself. If it does go to 40 degrees then I'd try another sensor and see what happens. Hope this helps and have an awesome day Glenn.

Hi Joe, I'm glad to help! The ambient temp sensor connects to the "Front Control Module" and when working properly will send the signal from the sensor to the overhead as well as other places that need an ambient signal. NOTE: Heres a simple way to see if the system is working properly. Unhook the connector at the Ambient Temp Sensor and the system should go to the default setting and the overhead display should read 40 degrees. If it does then the system is OK, replace the temp sensor. If it doesn't read 40 then various test must be performed to see if its the front control module or the overhead control unit. Hope this helps and have an awesome day Joe.

The ambient temp sensor is out of range maybe came unplugged or is faulty or the computer that reads the sensor is faulty or has a bad connection most ambient sensors are located behind the front grill and are pretty easy to get to enclosed is a typical bmw ambient sensor you didnt say your model so this is just a general idea

Hi ruswashingto,

The air conditioner may not work properly if your ambient temp is reading -40. The a/c control unit monitors ambient temp so that it does not operate at too low outside temps. I would recommend fixing the ambient temp sensor and rechecking your a/c operation.

the sensor should be located behind the front bumper grill.look through the bumper grill and you should see the ambient temp sender.on the dash,does the display where the temperature used to read have 3 dash lines?if so there is an open circuit in the wiring to the sensor.this will cause the aircon not to work..good luck.

LOOK ON DASHBOARD AREA FOR A LITTLE BUBBLE LOOKING THING PROTUDING UP SOMETIMES NEAR WINDSHEILD

Ambient Sensor (Auto A/C Model)

REMOVAL

1. Open the front hood.
2. Disconnect the ground cable from battery.
3. Disconnect the ambient sensor connector
   1. Remove the ambient sensor from radiator lower panel.
   INSTALLATION
   
   Install in the reverse order of removal.
   

There are four sensors for ambient tempurature and they work in unison to provide information to the temp reading on the dash, the heater control head ( where to direct air, blending of warm/cold/outside/inside air flapper controls) depending on the ambient temp and the inside air temp sensor located just above the radio as well as the sun sensor on the top of the dash as well as the a/c compressor head.

When you start your car, the body control module takes the readings from all sensors, outside air temp located in front of the radiator, air temp sensor located in the airbox ( senses temp of air being drawn in from the outside into the air box), coolant temp, inside air temp sensor and the sun sensor on top of the dash (this is why it takes a few seconds for the climate control system to begine when you start the car). The intake air sensor is 1st priority, inside air second, coolant third, ambient 4th and sun 5th. For instance, if the sun sensor reads the sun is hot but the interior sensor reads cold, the inside akes priority. The goal is for the system to achieve a tempurature inside the car that matches the selected temp. It uses all of the sensors to set the system up to achieve that goal as quickly as possible.

Example; Its mid afternoon, sunny and 40 degrees outside adn your in stop and go traffic. The intake sensor reads 40 degrees, the outside sensor reads 60 degrees (heat from radiator...engine heat protrudes into cabin) and the sun sensor reads high (sun is strong). The system is set for 72. priority one sensor reads 40, inside sensor reads 65, ambient reads 60= system will blow hot air to the floor out put, dash outlets will lightly flow 65 degree air so the sun doesnt roast you yet your feet are cold(if it blew hot air from all outlets, your upper body would be hot but your legs/feet would be cold). as the interior sensor reaches desired temp, air will be distrubuted through thee dash, defrost and floor with the warmest air coming out the floor and defrost, coolest air out the dash vents. Its a complex system!

The two sensors that will screw the system up the most are the intake and interior sensors. the system will function reasonably well with just those two sensors though it wont blend air temps between outlets if the sun sensor isnt working. If the outside sensor fails, it simply uses the intake sensor, if the intake sensor fails it will rely on the front sensor. However, since the intake takes priority over the outside sensor, if the intake sensor sends incorrect resistance info rather than failing, it will take priority and cause the unit to malfunction such as in your case.

The intake air sensor can be changed from the outside with patience. If it where me, I would pay the two hrs labor and let the dealer do it right.

Kevin,
Kevins Small Engine service,
South Berwick ME. 03908

yes it is located on the left bottom part of grill area,it is probly loose reinsert it in place it should work after driving for a while.