Test Procedure

WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2012 Lincoln Navigator L, 2012 Lincoln Navigator, 2012 Lincoln MKZ, 2012 Lincoln MKX, and 2012 Lincoln MKT. However, it is still accessible from the selected car via links, so may be relevant.

FA1 CHECK FOR DTCS

Are DTCs P0071, P0072, P0073 or P0074 present?

Yes	No
For DTC P0071, GO to FA8. For DTC P0072, GO to FA2. For DTC P0073, GO to FA3. For DTC P0074, GO to FA7.	Unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. REFER to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX , if a driveability concern exists.

FA2 DTC P0072: INDUCING THE OPPOSITE DTC

NOTE: The AAT is disconnected to simulate the opposite DTC.

Ignition OFF.
AAT Sensor connector disconnected.
Ignition ON, engine OFF.
Carry out the PCM self-test.

Is the DTC P0073 present?

Yes	No
INSTALL a new AAT sensor. REFER to the appropriate Electronic Engine Controls article. Clear the PCM DTCs. REPEAT the self-test.	GO to FA4.

FA3 DTC P0073: INDUCING THE OPPOSITE DTC

NOTE: DTCs will set as a result of the connector being disconnected.

Ignition OFF.
AAT Sensor connector disconnected.

Connect a 5 amp fused jumper wire between the following:

Point A AAT Sensor Connector, Harness Side	Point B AAT Sensor Connector, Harness Side
AAT	SIGRTN

Ignition ON, engine OFF.
Carry out the on-demand self-test.

Is DTC P0072 present?

Yes	No
INSTALL a new AAT sensor. REFER to the appropriate Electronic Engine Controls article. Clear the PCM DTCs. REPEAT the self-test.	GO to FA4.

FA4 CHECK THE AAT AND SIGRTN CIRCUITS FOR AN OPEN

Ignition OFF.
For Fiesta,
IPC connector disconnected.

Measure the resistance between:

(+) AAT Sensor Connector, Harness Side	(-) IPC Connector, Harness Side
AAT	AAT - Pin 20
SIGRTN	SIGRTN - Pin 19

For all others,
PCM connector disconnected.

Measure the resistance between:

(+) AAT Sensor Connector, Harness Side	(-) PCM Connector, Harness Side
AAT	AAT
SIGRTN	SIGRTN

Are the resistances less than 5 ohms?

Yes	No
GO to FA5.	REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test.

FA5 CHECK THE AAT CIRCUIT FOR A SHORT TO GROUND

Measure the resistance between:

(+) AAT Sensor Connector, Harness Side	(-)
AAT	Ground

Is the resistance greater than 10K ohms?

Yes	No
GO to FA6.	REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.

FA6 CHECK THE AAT AND SIGRTN CIRCUITS FOR A SHORT TO VOLTAGE

Ignition ON, engine OFF.

Measure the voltage between:

(+) AAT Sensor Connector, Harness Side	(-)
AAT	Ground
SIGRTN	Ground

Is any voltage present?

Yes	No
REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test.	GO to FA7.

FA7 INTERMITTENT CHECK

Ignition OFF.
AAT Sensor connector connected.
For Fiesta,
IPC connector connected.
Ignition ON, engine OFF.
Access the PCM and monitor the OUTDR_TMP (TEMP) PID.
For all others,
PCM connector connected.
Ignition ON, engine OFF.
Access the PCM and monitor the AAT_V (VOLT) PID.
While observing the PID, carry out the following:
- Lightly tap on the sensor and wiggle the accessible harness from the sensor to the control module
- Wiggle the sensor connector.
- Look for sudden changes in the temperature or voltage when the sensor is tapped and the harness and connector are wiggled

Is a concern present?

Yes	No
REPAIR as necessary. Clear the PCM DTCs. REPEAT the self-test.	GO to FA8.

FA8 TEMPERATURE 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.
For Fiesta,
Access the PCM and monitor the OUTDR_TMP (TEMP) PID.
For all others,
Access the PCM and monitor the AAT (TEMP) PID.
Access the PCM and monitor the IAT (TEMP) and ECT (TEMP) PIDs.

Are the temperature readings within 18°C (32.4°F) of each other?

Yes	No
For Fiesta, GO to FA9. For all others, GO to FA10.	INSTALL a new AAT sensor. REFER to the appropriate Electronic Engine Controls article. RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) . REPEAT the self-test.

FA9 CHECK FOR CORRECT INSTRUMENT PANEL CLUSTER (IPC) OPERATION

Disconnect all the IPC connectors.
Visually inspect for:
- pushed out pins
- corrosion
Connect all the IPC connectors and make sure they seat correctly.
Operate the system and verify the concern is still present.

Is the concern still present?

Yes	No
INSTALL a new IPC. REFER to the appropriate Instrumentation, Message Center, and Warning Chimes article.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

FA10 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. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.