Ambient Air Temperature Issue

[mrkazzbusta]

Hi All,

First time post, but I figured I would share this. I have searched for information on my new 2011 explorer and can only imagine I am not the only one running into a shortage of information. I got the 2011XLT 202A package 4 days ago, and noticed that the outside temperature reading was either "---" or "-40" all the time. Normally when this happens the thing you are looking for is called the "Ambient Temperature Sensor" and when it's reading is stuck maxed out at -40 or "---" that means there is either an open circuit or a short. Now, after asking the dealer for the location of it so I could see if the wire had come loose, the service manager sent me this, and I wanted to share as it is some good information to have. The sensor is at the bottom "C132"

Long story short, the sensor was broken off, must have either came from the factory like that, or some stray rock made it though the grill (it's made of plastic after all)... if you look through the black rectangles in the on the bottom driver side you will see the mount for this sensor. You have to get under the vehicle to follow the wire.

-Tony

 

[cg13]

nice post. now where can we get the program that shows all those pretty diagrams

 

[uniquename]

nice post. now where can we get the program that shows all those pretty diagrams

It's likely the service manual, nothing special except we don't have it

 

[1995E]

Oh nos. I'm having the same problem =(

 

[tadams19]

I have a 2011 EX XLT and am having issues getting the temperature to show up on dash as well as MFT screen. It shows either 3 dashes "---" or -40.

I believe I have a faulty Ambient Air Sensor but have been all over the vehicle (and google) trying to find out where it is located.

Anyone have ideas? Am I headed in the correct direction believing it is the sensor?

Thanks in advance!

 

[peterk9]

Here ya go. It's behind the front bumper. Hope this helps.
12A647
(DY-1160)
Ford Ambient Air Temperature Sensor
Outside Air Temperature Sensor (OAT)
$12.24

Peter

 

[MDearmon]

My wife ran over a piece of truck tire on the highway recently and it knocked the lower plastic trim grill out of her front bumper - didn't break it, just knocked it loose. After that, her outside air temperature readout on her Sync display doesn't show a temp, just "---". I'm assuming that either the ambient air temp sensor was knocked loose, knocked off or broken - but I can't find the blasted thing for the life of me and I can't find any info on it for trucks this new. Can anyone help? The part is only $7.95 and I hate to pay the dealer $100 in labor to go get it put on, when, if I can find it, I'm sure I can do it pretty easily myself. I know that on older models (and my 2013 FX4), it's on the driver's side radiator mount, but I sure can't locate it on hers... any help would be greatly appreciated.

 

[MDearmon]

Removal

NOTE: If replacing the Ambient Air Temperature sensor a reset must be performed. Select the A/C and Recirc buttons simultaneously, then release both, Within 2 seconds select A/C button again.

1. With the vehicle in NEUTRAL, position it on a hoist. REFER to Section 100-02, Jacking and Lifting.

1. Detach the lower bumper grill from the lower bumper by pushing the grill toward the rear of the vehicle at each of the fastener locations. Once the grille is detached, position the grille out of the way inside the lower bumper to gain access to the ambient air temperature sensor.

Great information, but WHERE behind that lower bumper grill is it located? Right, left, center? Is it attached to the radiator, to the bumper, to something else?

 

[peterk9]

Great information, but WHERE behind that lower bumper grill is it located? Right, left, center? Is it attached to the radiator, to the bumper, to something else?

Welcome to the Forum.
Your thread has been merged with this one. There is also a "Component Location" thread in the "List of Useful Threads" located at the beginning of this sub forum and in diagram 2 they show the sensor location. http://www.explorerforum.com/forums...015-explorer-component-location-views.425587/
Hope this helps. I believe there is another thread with a picture but I haven't yet found it using the 'Search' program.

Peter

 

[finally03gt]

Hi folks. New around here. I have a 2015 Explorer Sport. Something took out the AAT sensor in the grill. I have a new connector, and new sensor installed. I'm still reading -40 connected, and AC clutch won't engage. I'm fairly certain I have the polarity correct when I soldered the new pig tail in, but would really like to double check the signal and return pin out. Anyone have that info?? Honestly, I'm not sure the pin out even matters with a thermo-resistor, should read the same in either direction, but....... you know how that goes. Also, I just stumbled across a 2011 article about the PCM logic, and apparently I may just need to get it over 20 mph for 90 seconds, but I'd still like to double check my pins.

 

[sheltonfilms]

-40 means you have an open circuit as this is the lowest temp available (or to be calculated). highest resistance of sensor is when it's cold. Resistance goes down when hot. To make sure your pigtail is connected right (soldered) you need to jump the terminals together at the end. This should cause the temp to read high.

Page 6 on this site:

http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=874990

 

[sheltonfilms]

Also you should get about 5 Volts across both wires.

 

[jmr061]

Ye/Gn - Pin 1
Ye/Violet - Pin 2

If you are holding the connector in your hand looking at the inside of the connector with the tab side up, pin 2 is left, 1 is right.

NOTE: If replacing the Ambient Air Temperature sensor a reset must be performed. Select the A/C and Recirc buttons simultaneously, then release both, Within 2 seconds select A/C button again.

 

[finally03gt]

Thanks for the reply. I do have 5 VDC (well 4.98) across the pins. I wanted to make sure that I have the pigtail connected so that signal and return were correct at the sensor, if that even matter with a thermo-resistor.

Unplugged I get --- and the AC works
Plugged I get -40F and no AC
Shorted I got -40F and checking with my scanner set a PO073 sensor voltage high code (seems logical for a short). Is it possible that when the sensor is out of voltage range (shorted) it throws -40 as a default?

 

[finally03gt]

Ye/Gn - Pin 1
Ye/Violet - Pin 2

If you are holding the connector in your hand looking at the inside of the connector with the tab side up, pin 2 is left, 1 is right.

NOTE: If replacing the Ambient Air Temperature sensor a reset must be performed. Select the A/C and Recirc buttons simultaneously, then release both, Within 2 seconds select A/C button again.

That and the print is just what I needed, thanks. I'll double check voltage, try the reset and try driving it when my bride bring it home...lol.

 

[peterk9]

Hi folks. New around here. I have a 2015 Explorer Sport. Something took out the AAT sensor in the grill. I have a new connector, and new sensor installed. I'm still reading -40 connected, and AC clutch won't engage. I'm fairly certain I have the polarity correct when I soldered the new pig tail in, but would really like to double check the signal and return pin out. Anyone have that info?? Honestly, I'm not sure the pin out even matters with a thermo-resistor, should read the same in either direction, but....... you know how that goes. Also, I just stumbled across a 2011 article about the PCM logic, and apparently I may just need to get it over 20 mph for 90 seconds, but I'd still like to double check my pins.

Welcome to the Forum.

Peter

 

[finally03gt]

Welcome to the Forum.
Your thread has been merged with this one. There is also a "Component Location" thread in the "List of Useful Threads" located at the beginning of this sub forum and in diagram 2 they show the sensor location. http://www.explorerforum.com/forums...015-explorer-component-location-views.425587/
Hope this helps. I believe there is another thread with a picture but I haven't yet found it using the 'Search' program.

Peter

Thanks, I found this thread also, but it was from 2011 with a broken reference photo. I did send the OP a message to see if he still had the info handy. Thanks for keeping the boards clean.

 

[finally03gt]

It just occurred to me, I still don't know which pin carries the 5 volts. From the diagram, pin 2 has several components in common that would make me believe it is supplied voltage, and pin 1 is dedicated to AAT at the PCM, lending to the idea that it is the signal return. BUT, the RE407 that is common on pin 2 is labeled "SIGRTN" at the PCM. So, if I go black to chassis on my meter, which pin on the AAT connector should carry the supply 5 VDC?

 

[sheltonfilms]

It just occurred to me, I still don't know which pin carries the 5 volts. From the diagram, pin 2 has several components in common that would make me believe it is supplied voltage, and pin 1 is dedicated to AAT at the PCM, lending to the idea that it is the signal return. BUT, the RE407 that is common on pin 2 is labeled "SIGRTN" at the PCM. So, if I go black to chassis on my meter, which pin on the AAT connector should carry the supply 5 VDC?

Sorry I got the -40 mixed up. I was looking at buying another explorer that had the sensor ripped off. I think what I did was put the two wires together and got -40 and somehow thought that was what it said when it was just hanging.

Pin 1 (yellow/green) should be the positive side. Also the 5V may not be a 5V differential between that pin and chassis ground (SignalRTN maybe isolated from chassis ground).

THis is how this is wired up:

***********************Inside PCM*****************
5V regulator
|
>
< Inline resistor of known value (sometimes something like 1K) call it Rint
>
<
|
|------------Vref
|
|
******************************************************* End of pcm*****8
| (pin 29)
|
| (Pin1)
[Ambient temp sensor] Ramb
| (pin 2)
|
| (pin 56)
***************************Inside PCM***********************
| Signal Return (ground)
**************************************************************

Vref= 5V * Ramb/ (Ramb+ Rint)

Computer converts Vref into a digital format using an analog to digital converter and then converts this to a temperature.

As Ramb gets larger Ramb/(Ramb+Rint) approaches 1 so Vref approaches 5.

As Ramb gets smaller Ramb/(Ramb+Rint) approaches 0 so Vref approaches 0.

 

[sheltonfilms]

Sorry I got the -40 mixed up. I was looking at buying another explorer that had the sensor ripped off. I think what I did was put the two wires together and got -40 and somehow thought that was what it said when it was just hanging.

Pin 1 (yellow/green) should be the positive side. Also the 5V may not be a 5V differential between that pin and chassis ground (SignalRTN maybe isolated from chassis ground).

THis is how this is wired up:

***********************Inside PCM*****************
5V regulator
|
>
< Inline resistor of known value (sometimes something like 1K) call it Rint
>
<
|
|------------Vref
|
|
******************************************************* End of pcm*****8
| (pin 29)
|
| (Pin1)
[Ambient temp sensor] Ramb
| (pin 2)
|
| (pin 56)
***************************Inside PCM***********************
| Signal Return (ground)
**************************************************************

Vref= 5V * Ramb/ (Ramb+ Rint)

Computer converts Vref into a digital format using an analog to digital converter and then converts this to a temperature.

As Ramb gets larger Ramb/(Ramb+Rint) approaches 1 so Vref approaches 5.

As Ramb gets smaller Ramb/(Ramb+Rint) approaches 0 so Vref approaches 0.

Need to see what resistance value the sensor has. Have any resistors laying around?