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Year = 2011
Model = Mustang
Engine = 5.0L
VIN =
IDS Version = Not Available
Intake Air Temperature (IAT) Sensor
This pinpoint test is intended to diagnose the following:
 IAT sensor (12A697)
 integrated mass air flow/intake air temperature ( MAF/IAT) sensor (12B579)
 harness circuits: IAT and SIGRTN
 powertrain control module (PCM) (12A650)
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IAT Sensor Connector
Harness Side
Circuit
SIGRTN (Signal Return)
IAT (Intake Air Temperature)
VPWR (Vehicle Power)
MAF (Mass Air Flow)
Pin
4
2
3
5
PCM Connector - For PCM connector views or
reference values, refer to Section 6.
Harness Side
Circuit
IAT (Intake Air Temperature)
SIGRTN (Signal Return)
Pin
B47
B2
DA1 : PRELIMINARY DIAGNOSIS
 Are DTCs P009A, P0111, P0112, P0113, P0114, or P1112 present?
Yes
For DTCs P009A, P0111, P0112, P0113, P0114 or
P1112, Go to DA2.
For all others, GO to Section 4, Diagnostic Trouble
Code (DTC) Charts and Descriptions.
No
For symptoms without DTCs,
Go to DA2.
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the MAF/IAT sensor to determine which circuits to measure
 Ignition OFF.
 IAT Sensor connector disconnected.
 PCM connector disconnected.

Measure the resistance between:
(+)
IAT Sensor Connector, Harness Side
SIGRTN - Pin 4

Ground
Measure the resistance between:
(+)
IAT Sensor Connector, Harness Side
IAT - Pin 2
SIGRTN - Pin 4
SIGRTN - Pin 4

(-)
(-)
PCM Connector, Harness Side
IAT - Pin B47
SIGRTN - Pin B2
MAF RTN
Is the resistance less than 5 Ohm?
Yes
Go to DA3.
No
REPAIR the open circuit.
Clear the PCM DTCs. REPEAT the self-test.
DA3 : CHECK FOR A SHORT BETWEEN CIRCUITS IN THE HARNESS

Measure the resistance between:
(+)
IAT Sensor Connector, Harness Side
IAT - Pin 2

Ground
Measure the resistance between:
(+)
IAT Sensor Connector, Harness Side
IAT - Pin 2
IAT - Pin 2
IAT - Pin 2
IAT - Pin 2

(-)
(-)
IAT Sensor Connector, Harness Side
VPWR - Pin 3
MAF RTN
SIGRTN - Pin 4
MAF - Pin 5
Are the resistances greater than 10K ohms?
Yes
Go to DA4.
No
REPAIR the short circuit.
Clear the PCM DTCs. REPEAT the self-test.
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Yes
REPAIR the short circuit.
Clear the PCM DTCs. REPEAT the self-test.
No
Go to DA5.
DA5 : INTERMITTENT CHECK
 Ignition OFF.
 PCM connector connected.
 IAT Sensor connector connected.
 Ignition ON, engine OFF.
 Access the PCM and monitor the IAT (VOLT) PID.
 While observing the PID, wiggle, shake, and bend small sections of the wiring harness working from the
sensor to the PCM
 Lightly tap on the IAT sensor and wiggle the harness connector to simulate road shock.
 Does the IAT PID reading change?
Yes
REPAIR as necessary or INSTALL a
new IAT sensor. REFER to the Workshop Manual
Section 303-14, Electronic Engine Controls. RESET
the keep alive memory ( KAM). REFER to Section 2,
Resetting The Keep Alive Memory (KAM).
REPEAT the self-test.
No
Go to DA6.
DA6 : INTAKE AIR TEMPERATURE ( IAT ) SENSOR AMBIENT AIR TEMPERATURE ( AAT) SENSOR
CORRELATION
NOTE: Check temperature values while engine is at ambient temperature, cold soak the engine for a
minimum of 8 hours while not in direct sun light, if necessary.
 Ignition ON, engine OFF.
 Access the PCM and monitor the IAT (TEMP) PID.
 For Fiesta,
 Access the PCM and monitor the OUTDR_TMP (TEMP) PID.
 For all others,
 Access the PCM and monitor the AAT (TEMP) PID.
 Are the temperature readings within 18ºC (32.4ºF) of each other?
Yes
Go to DA7.
No
INSTALL a new IAT sensor.
REFER to the Workshop Manual Section 303-14,
Electronic Engine Controls. RESET the keep alive
memory ( KAM). REFER to Section 2, Resetting The
Keep Alive Memory (KAM).
REPEAT the self-test.
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Connect a 5 amp fused jumper wire between the following:
Point A
IAT Sensor Connector, Harness Side
IAT - Pin 2
Point B
IAT Sensor Connector, Harness Side
SIGRTN - Pin 4
Record the IAT PID value
Does the IAT PID change from greater than 3.0 volts to less than 0.20 volt when the jumper is
connected?


Yes
INSTALL a new IAT sensor.
REFER to the Workshop Manual Section 303-14,
Electronic Engine Controls. RESET the keep alive
memory ( KAM). REFER to Section 2, Resetting The
Keep Alive Memory (KAM).
REPEAT the self-test.
No
Go to DA8.
DA8 : CHECK FOR CORRECT PCM OPERATION
 Disconnect all the PCM connectors.
 Visually inspect for:
—pushed out pins
—corrosion
 Connect all the PCM connectors and make sure they seat correctly.
 Carry out the PCM self-test.
 Verify the concern is still present.
 Is the concern still present?
Yes
No
INSTALL a new PCM.
The system is operating correctly at this time. The
REFER to Section 2, Flash Electrically Erasable
concern may have been caused by a loose or
Programmable Read Only Memory (EEPROM),
corroded connector.
Programming the VID Block for a Replacement PCM.
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