Where is the IAC sensor located?

[rumblecloud]

Can anyone tell me where the IAC sensor is located on my 94 4.0L?
Is this the same as the MAF sensor?

Reason I ask is that I was d'king around and disconnected a connector on the intake manifold to get a better grip on the PCV so I could yank it out and replace it. I reconnected the connector and now I am getting a 113 code.

Thanks

Old image - doesn't look this bad anymore.

 

[RonD]

In the picture, that's IAT(intake air temp) sensor circled
It will set that code if you turned the key on and it was unplugged, so plug it back in and the code should clear itself in a day or two of driving, once the computer decides it was just a "glitch" and not a real issue
Or you can unhook the battery for 5 min., thats will clear all the codes, but also the radio stations and clock, lol

IAC(idle air control) is not a sensor, its a "control", IAC Valve, looks like a can on its side on the upper intake, like the IAT sensor, but it on the throttle body, has 2 wires and runs on 12volts

Sensors all use 5volts
113 IAT sensor is/was high or open - IAT
Computer sends IAT 5volts, and expects to get back 4v(cold) down to 0.5v(hot), if it gets 0v then it sets this code, "open circuit", unplugged or could be a bad sensor

Computer pulses the ground wire on the IAC Valve to open and close the valve letting in more or less air to set idle RPMs
Fords use a true solenoid valve, so this should only be replaced with a Motorcraft or Hitachi brand IAC Valve
Other brands work but you will get odd up and down idles and stalling

 

[rumblecloud]

Gotcha. Thanks.
Adding to my already confused state is the code 113 and the "Fault Code Definition" in the booklet I have, which reads:
"Intake air charge temperature sensor above maximum voltage /-40° indicated."

I assumed it meant the Intake Air Charge (IAC) DUH. Sorry and thanks again.

 

[RonD]

Its called IAT or ACT(air charge temp)

Ford 3-digit codes found here: https://www.therangerstation.com/tech_library/3digitcodes.shtml

OBD1 has 3 codes for the IAT/ACT
112 Intake Air Temperature (IAT) sensor is/was low or grounded - IAT
113 IAT sensor is/was high or open - IAT
114 IAT sensor out of range - IAT

112 or 114 tells you the computer was "seeing" something on the "return" wire from this sensor, it can only "assume" each sensor is plugged in and getting the 5volts

113 is the only code that would fit disconnected wires, if they were

-40degF is computers lowest temp, and +350degF is the highest
And it defaults to the lowest temp when there is an issue, so -40

When you get any code, OBD1 or OBD2, you should always look it up on a full list first
The computer has several codes to choose from for each sensor or system
So the codes it DID NOT choose can tell you as much, or more, than the code it did choose
The un-chosen codes tell you what its NOT, which helps you diagnose what it IS


And believe it or not they(SAE) actually document what abbreviations(acronyms) are acceptable every few years
This is from 2002 SAE(society of automotive engineers): https://law.resource.org/pub/us/cfr/ibr/005/sae.j1930.2002.pdf

Didn't see ACT but IAT is in there alot