IAT reading hot

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jruppert

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Just curious about what the iat readings should show against actual outdoor temp. It is 65 degrees out and my scanner is showing crazy iat temps. It started out at 110 but now showing 122 after 10 minutes of idle.
 

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Bedrck47

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and your profile shows 2004

Have you tried cleaning the IAT sensor with some maf spray. Also check to see if the connector contacts are clean and tight check for any loose pins in the connector.

Intake Air Temperature (IAT) Sensor
Introduction DA: Pinpoint Tests

--------------------------------------------------------------------------------

This pinpoint test is intended to diagnose the following:

integrated mass air flow/intake air temperature (MAF/IAT) sensor (12B579)
harness circuits: IAT and SIGRTN
powertrain control module (PCM) (12A650)
Voltage values calculated for VREF equal 5 volts. These values can vary by 15% due to sensor and VREF variations.






TEMPERATURE SENSOR VOLTAGE AND RESISTANCE SPECIFICATIONS Temperature Temperature Sensor Values
°C °F Voltage Resistance (K ohms)
120 248 0.28 1.18
110 230 0.36 1.55
100 212 0.47 2.07
90 194 0.61 2.80
80 176 0.80 3.84
70 158 1.05 5.37
60 140 1.37 7.70
50 122 1.77 10.97
40 104 2.23 16.15
30 86 2.74 24.27
20 68 3.26 37.30
10 50 3.73 58.75
0 32 4.14 95.85
-10 14 4.45 160.31


Mass Air Flow/Intake Air Temperature (MAF/IAT) Sensor Connector





Pin Circuit
4 MAF RTN (Mass Air Flow Return)
2 SIGRTN (Signal Return)
1 IAT (Intake Air Temperature)


Powertrain Control Module (PCM) Connector
For PCM connector views or reference values, refer to Section 6 .



Vehicle Connector Pin Circuit
Crown Victoria,
Grand Marquis,
Town Car 170 Pin T41
E22 SIGRTN
IAT
Edge,
F-150,
Mark LT,
MKX 190 Pin E58
E22 SIGRTN
IAT
Escape,
Focus,
Mariner 150 (50-50-50) Pin B41
B20 SIGRTN
IAT
Expedition,
Fusion,
Milan,
MKZ,
Navigator 140 Pin B58
B43 SIGRTN
IAT
Five Hundred,
Freestyle,
Montego 150 (50-50-50) Pin E41
B26 SIGRTN
IAT
Freestar/Monterey,
Taurus 104 Pin 91
39 SIGRTN
IAT
All other vehicles 170 Pin E58
E22 SIGRTN
IAT
 

Bedrck47

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some information wasn't copied send me a PM with your e-mail address so I can resend the information
 
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jruppert

jruppert

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Thanks for your help. I went to update my information and saw that my Model was updated but the year was 2004. I used to have a 2004 and sold it to buy the EL.

I drove it for an hour this afternoon on expressway. After 40 minutes of driving, the IAT was reading at 70 degrees. I would say it was 65 out today. The climate control read 68. My Actron showed 59 for outside temp. Not sure what sensor it was using to get that temp though.
 

Bedrck47

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again check all the connectors and clean the IAT sensor
You may want to use a little dielectric grease on the electrical contacts
 

montecarlo31

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Thanks for your help. I went to update my information and saw that my Model was updated but the year was 2004. I used to have a 2004 and sold it to buy the EL.

I drove it for an hour this afternoon on expressway. After 40 minutes of driving, the IAT was reading at 70 degrees. I would say it was 65 out today. The climate control read 68. My Actron showed 59 for outside temp. Not sure what sensor it was using to get that temp though.

That's about right. I'll see my IATs creep up on any of my vehicles at idle, even those with cool air intakes. That's the nature of the beast when you are running an engine at almost 200 degrees and exhaust temps even higher just inches from the airbox.

You can do things to lower the IATs, drawing in cool air from outside, insulating the airbox or CAI. You can also wrap manifolds and headers to help prevent heat soak.

again check all the connectors and clean the IAT sensor
You may want to use a little dielectric grease on the electrical contacts

His sensors sound just fine, It isn't uncommon to see exactly what he is describing especially at idle. One of the biggest killers of power is heat soak and with summer upon us you will see lower HP output.
 

Bedrck47

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montecarlo31;218131His sensors sound just fine said:
I agree with that
but his original post was reporting big fluctuations in the temps which would point to a bad or loose connection
 

montecarlo31

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I agree with that
but his original post was reporting big fluctuations in the temps which would point to a bad or loose connection

Those temps in the first post are well within the normal range for a mechanical clutch cooled vehicle sitting at idle. I see 10 degree jumps here in the south from just slowing in traffic and sitting at a standstill for 2-3 minutes. Unfortunately it's the nature of the best with emission controls and fuel economy regulations.
 
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