Test Procedure
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- DA1 PRELIMINARY DIAGNOSIS
Are DTCs P00AB, P00AC, P00AD, P0111, P0112, P0113, P0114, or P1112 present?
Yes No For DTCs P00AB or P0111, GO to DA7
For all others, GO to DA2RETURN to Symptom Charts for further direction. - DA2 CHECK FOR AN OPEN NOTE: Only measure the circuits that apply to the vehicle being diagnosed.
- Ignition OFF.
- PCM connector disconnected.
- For DTCs P00AC, or P00AD,
- MAF21/IAT21 Sensor connector disconnected.
- Measure the resistance between:
(+) MAF21/IAT21 Sensor Connector, Harness Side (-) PCM Connector, Harness Side IAT21 - Pin 2 IAT21 SIGRTN - Pin 4 SIGRTN - For EcoSport 1.5L, Explorer 3.3L, F-150 3.3L, F-150 5.0L, F-Series Super Duty 6.2L, KA, Ranger 2.5L and Transit 3.5L TIVCT,
- MAPT Sensor connector disconnected.
- Measure the resistance between:
(+) MAPT Sensor Connector, Harness Side (-) PCM Connector, Harness Side IAT IAT SIGRTN SIGRTN - For all others,
- IAT Sensor 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 DA3 REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - DA3 CHECK FOR A SHORT TO GROUND
- For DTCs P00AC, or P00AD,
- Measure the resistance between:
(+) MAF21/IAT21 Sensor Connector, Harness Side (-) IAT21 - Pin 2 Ground - For EcoSport 1.5L, Explorer 3.3L, F-150 3.3L, F-150 5.0L, F-Series Super Duty 6.2L, KA, Ranger 2.5L and Transit 3.5L TIVCT,
- Measure the resistance between:
(+) MAPT Sensor Connector, Harness Side (-) IAT Ground - For all others,
- Measure the resistance between:
(+) IAT Sensor Connector, Harness Side (-) IAT Ground
Is the resistance greater than 10K ohms?
Yes No GO to DA4 REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - DA4 CHECK FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- For DTCs P00AC, or P00AD,
- Measure the voltage between:
(+) MAF21/IAT21 Sensor Connector, Harness Side (-) IAT21 - Pin 2 Ground - For EcoSport 1.5L, Explorer 3.3L, F-150 3.3L, F-150 5.0L, F-Series Super Duty 6.2L, KA, Ranger 2.5L and Transit 3.5L TIVCT,
- Measure the voltage between:
(+) MAPT Sensor Connector, Harness Side (-) IAT Ground - For all others,
- Measure the voltage between:
(+) IAT Sensor Connector, Harness Side (-) IAT Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test.For DTCs P00AB, P00AC, or P00AD, INSTALL a new MAF21/IAT21 sensor. REFER to the appropriate Electronic Engine Controls article.
Clear the PCM DTCs. REPEAT the self-test.
For all others, GO to DA5 - DA5 INTERMITTENT CHECK
- Ignition OFF.
- PCM connector connected.
- For EcoSport 1.5L, Explorer 3.3L, F-150 3.3L, F-150 5.0L, F-Series Super Duty 6.2L, KA, Ranger 2.5L and Transit 3.5L TIVCT,
- MAPT Sensor connector connected.
- For all others,
- 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 sensor and wiggle the harness connector to simulate road shock.
Does the IAT PID reading change?
Yes No REPAIR as necessary.
RESET the keep alive memory (KAM). Refer to Resetting The Keep Alive Memory (KAM).
REPEAT the self-test.GO to DA6 - DA6 CHECK THE IAT CIRCUIT VOLTAGE CYCLING INTEGRITY
- Ignition OFF.
- For EcoSport 1.5L, Explorer 3.3L, F-150 3.3L, F-150 5.0L, F-Series Super Duty 6.2L, KA, Ranger 2.5L and Transit 3.5L TIVCT,
- MAPT Sensor connector disconnected.
- Ignition ON, engine OFF.
- Access the PCM and monitor the IAT (VOLT) PID.
- Record the IAT PID value.
- Connect a 5 amp fused jumper wire between the following:
Point A MAPT Sensor Connector, Harness Side Point B IAT Ground - Record the IAT PID value.
- For all others,
- IAT Sensor connector disconnected.
- Ignition ON, engine OFF.
- Access the PCM and monitor the IAT (VOLT) PID.
- Record the IAT PID value.
- Connect a 5 amp fused jumper wire between the following:
Point A IAT Sensor Connector, Harness Side Point B IAT Ground - 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 No For EcoSport 1.5L, Explorer 3.3L, F-150 3.3L, F-150 5.0L, F-Series Super Duty 6.2L, KA, Ranger 2.5L and Transit 3.5L TIVCT, INSTALL a new MAPT sensor.
For all others, INSTALL a new IAT 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.GO to DA8 - DA7 INTAKE AIR TEMPERATURE (IAT) 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 sunlight, if necessary.NOTE: All PIDs may not be available on all vehicles.
- Ignition OFF.
- IAT Sensor connector connected.
- Ignition ON, engine OFF.
- For Aviator, Continental 2.0L, Edge, Expedition, Explorer 2.3L, Explorer 3.0L, Ford GT, Nautilus, Navigator and Transit 3.5L GTDI,
- Access the PCM and monitor the AAT (TEMP), CAC_T (TEMP), IAT (TEMP) and IAT2 (TEMP) PIDs.
- For all others,
- Access the PCM and monitor the AAT (TEMP), CHT (TEMP), ECT (TEMP), ECT1 (TEMP) and IAT (TEMP) PIDs.
Are the temperature readings within 17°C (30°F) of each other?
Yes No GO to DA8 INSTALL a new IAT 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. - 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. 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.