Test Procedure
- DA1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)
Are DTCs P0111, P0112, P0113, P0114, or P1112 present?
Yes No For DTC P0111, GO to DA12.
For KOEO and KOER DTC P0112, GO to DA6.
For KOEO and KOER DTC P0113, GO to DA2.
For continuous memory DTCs P0112, P0113 or P1112, GO to DA9.
For DTC P0114, GO to DA9.For all others, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . - DA2 DTC P0113: CHECK THE IAT SIGNAL CIRCUIT NOTE: The DTC indicates the sensor signal is greater than the self-test maximum.
- IAT Sensor connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) IAT Sensor Connector, Harness Side (-) IAT Ground
Is the voltage between 4.5 - 5.5 V?
Yes No GO to DA3. GO to DA4. - DA3 CHECK THE IAT SENSOR RESISTANCE
- Ignition OFF.
- Measure the resistance between:
(+) IAT Sensor Connector, Component Side (-) IAT Sensor Connector, Component Side IAT SIGRTN
Is the resistance between 1K - 500K ohms?
Yes No GO to DA4. INSTALL a new IAT sensor. REFER to the appropriate Electronic Engine Controls article .
CLEAR the DTCs. REPEAT the self-test. - DA4 CHECK THE SIGNAL AND SIGRTN CIRCUITS FOR AN OPEN IN THE HARNESS
- PCM connector disconnected.
- Measure the resistance between:
(+) IAT Sensor Connector, Harness Side (-) PCM Connector, Harness Side IAT IAT SIGRTN SIGRTN
Are the resistances less than 5 ohms?
Yes No GO to DA5. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test. - DA5 CHECK THE SIGNAL FOR A SHORT TO VOLTAGE IN HARNESS
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) IAT Sensor Connector, Harness Side (-) IAT Ground
Is the voltage greater than 1 V?
Yes No REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to DA14. - DA6 DTC P0112: SIMULATE AN OPPOSITE SIGNAL TO THE PCM NOTE: The DTC indicates the sensor signal is less than the self-test minimum.
- IAT Sensor connector disconnected.
- Ignition ON, engine OFF.
- Access the PCM and monitor the IAT PID.
Is the voltage greater than 4.2 V?
Yes No INSTALL a new IAT sensor. REFER to the appropriate Electronic Engine Controls article .
CLEAR the DTCs. REPEAT the self-test.For Flex 3.5L GTDI,
MKS 3.5L,
MKT 3.5L, and
Taurus 3.5L GTDI, GO to DA8.
For all others, GO to DA7. - DA7 CHECK THE IAT CIRCUIT FOR A SHORT TO MAF RTN
- Ignition OFF.
- PCM connector disconnected.
- Measure the resistance between:
(+) IAT Sensor Connector, Harness Side (-) IAT Sensor Connector, Harness Side IAT MAF RTN
Is the resistance less than 5 ohms?
Yes No REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to DA8. - DA8 CHECK THE IAT CIRCUIT FOR A SHORT TO GROUND
- PCM connector disconnected.
- Measure the resistance between:
(+) PCM Connector, Harness Side (-) PCM Connector, Harness Side IAT SIGRTN - Measure the resistance between:
(+) PCM Connector, Harness Side (-) 12 Volt Vehicle Battery IAT Negative terminal
Is the resistance less than 5 ohms?
Yes No REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to DA14. - DA9 SELF-TEST DTCS P0112, P0113, P0114 OR P1112: INTERMITTENT CHECK
- Ignition ON, engine OFF.
- Access the PCM and monitor the IAT PID.
- While observing the PID, carry out the following:
- Tap on the sensor to simulate road shock
- Wiggle the sensor connector
Is there a large change in the voltage reading?
Yes No DISCONNECT and INSPECT the connector.
If OK, INSTALL a new IAT sensor. REFER to the appropriate Electronic Engine Controls article .
CLEAR the DTCs. REPEAT the self-test.GO to DA10. - DA10 CHECK THE ELECTRONIC ENGINE CONTROL (EEC) WIRING HARNESS
- Access the PCM and monitor the IAT PID.
- While observing the PID, wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.
Is there a large change in the voltage reading?
Yes No ISOLATE the concern. REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to DA11. - DA11 CHECK THE PCM AND VEHICLE HARNESS CONNECTORS
- Ignition OFF.
- PCM connector disconnected.
- IAT Sensor connector disconnected.
- Check for a loose connection, and damaged or corroded terminals.
Are the connectors and terminals OK?
Yes No The concern is not present at this time.
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test. - DA12 DTC P0111: CHECK THE RESISTANCE OF THE IAT SENSOR WITH THE ENGINE OFF NOTE: Verify the engine temperature is at ambient temperature before continuing with this test.
- Ignition OFF.
- IAT Sensor connector disconnected.
- Measure the resistance between:
(+) IAT Sensor Connector, Component Side (-) IAT Sensor Connector, Component Side IAT SIGRTN - Refer to the chart at the beginning of this test for the resistance specifications.
Is the resistance within specification?
Yes No GO to DA13. INSTALL a new IAT sensor. REFER to the appropriate Electronic Engine Controls article .
CLEAR the DTCs. REPEAT the self-test. - DA13 DTC P0111: CHECK THE RESISTANCE OF THE IAT SENSOR NOTE: Verify the engine is at operating temperature before taking the IAT reading.
- IAT Sensor connector connected.
- Run the engine until the engine temperature stabilizes.
- Ignition OFF.
- IAT Sensor connector disconnected.
- Measure the resistance between:
(+) IAT Sensor Connector, Component Side (-) IAT Sensor Connector, Component Side IAT SIGRTN - Refer to the chart at the beginning of this test for the resistance specifications.
Is the resistance within specification?
Yes No The concern is not present at this time.
CARRY OUT the OBD drive cycle to determine if fuel, HO2S, catalyst and misfire monitors can be executed.
REFER to ON BOARD DIAGNOSTIC (OBD) DRIVE CYCLE .
REPEAT the PCM self-test if necessary.INSTALL a new IAT sensor. REFER to the appropriate Electronic Engine Controls article .
CLEAR the DTCs. REPEAT the self-test. - DA14 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 and 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.