Operation CHARM: Car repair manuals for everyone.
Home >> Mercury >> 2009 >> Mariner 2WD L4-2.5L Hybrid >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Pinpoint Tests >> DA - Intake Air Temperature (IAT) Sensor >> DA - Test

DA - Test




DA: Intake Air Temperature (IAT) Sensor

DA: Introduction DA - Introduction



-------------------------------------------------

DA1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)

Are any of the following DTCs present during the PCM self-test: P0111, P0112, P0113, or P0114?

YES
For KOEO and KOER DTC P0113, GO to DA2
.

For KOEO and KOER DTC P0112, GO to DA6
.

For continuous memory DTC P0111, GO to DA11
.

For DTC P0114, GO to DA8
.

For all others, GO to DA8.

NO
Unable to duplicate or identify the concern at this time.

RETURN to Symptom Charts Symptom Related Diagnostic Procedures for further direction.


-------------------------------------------------

DA2 DTC P0113: CHECK THE IAT SIGNAL CIRCUIT

- The DTC indicates the sensor signal is greater than the self-test maximum.
- MAF/IAT Sensor connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:





Is the voltage between 4.5 - 5.5 V?

YES
GO to DA3.

NO
GO to DA4.


-------------------------------------------------

DA3 CHECK IAT SENSOR RESISTANCE

- Key in OFF position.
- Measure the resistance between:





Is the resistance between 1K - 500K ohms?

YES
GO to DA4.

NO
INSTALL a new MAF/IAT sensor.

Refer to Electronic Engine Controls.

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:





Are the resistances less than 5 ohms?

YES
GO to DA5.

NO
REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.


-------------------------------------------------

DA5 CHECK THE SIGNAL FOR A SHORT TO VOLTAGE IN HARNESS

- Key in OFF position.
- PCM connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:





Is the voltage greater than 1 V?

YES
REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

NO
GO to DA13.


-------------------------------------------------

DA6 DTC P0112: SIMULATE AN OPPOSITE SIGNAL TO THE PCM

Note: The DTC indicates the sensor signal is less than the self-test minimum.

- MAF/IAT Sensor connector disconnected.
- Key ON, engine OFF.
- Access the PCM and monitor the IAT PID.

Is the voltage greater than 4.2 V?

YES
INSTALL a new MAF/IAT sensor.

Refer to Electronic Engine Controls.

CLEAR the DTCs. REPEAT the self-test.

NO
Key in OFF position.

GO to DA7.


-------------------------------------------------

DA7 CHECK THE SENSOR SIGNAL FOR A SHORT TO GROUND

- PCM connector disconnected.
- Measure the resistance between:





- Measure the resistance between:





- Measure the resistance between:





Is the resistance greater than 10K ohms?

YES
GO to DA13.

NO
REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.


-------------------------------------------------

DA8 SELF-TEST DTCS P0112, P0113 OR P0114: INTERMITTENT CHECK

- Key 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
DISCONNECT and INSPECT the connector.

If OK, INSTALL a new MAF/IAT sensor.

Refer to Electronic Engine Controls for additional information.

CLEAR the DTCs. REPEAT the self-test.

NO
GO to DA9.


-------------------------------------------------

DA9 CHECK THE WIRING HARNESS

- Access the PCM and monitor the IAT PID.
- While observing the PID, wiggle, shake, and bend small sections of the wiring harness working from the sensor to the PCM.

Is there a large change in the voltage reading?

YES
ISOLATE the concern.

REPAIR as necessary.

CLEAR the DTCs. REPEAT the self-test.

NO
GO to DA10.


-------------------------------------------------

DA10 CHECK THE PCM AND VEHICLE HARNESS CONNECTORS

- PCM connector disconnected.
- MAF/IAT Sensor connector disconnected.

Are the connectors and pins OK?

YES
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Diagnostic Trouble Code (DTC) Charts and Descriptions Diagnostic Trouble Code Descriptions.

NO
REPAIR as necessary.

CLEAR the DTCs. REPEAT the self-test.


-------------------------------------------------

DA11 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.

- Key in OFF position.
- MAF/IAT Sensor connector disconnected.
- Measure the resistance between:





- Refer to the chart at the beginning of this test for the resistance specifications.

Is the resistance within specification?

YES
GO to DA12.

NO
INSTALL a new MAF/IAT sensor. Refer to Electronic Engine Controls.

CLEAR the DTCs. REPEAT the self-test.


-------------------------------------------------

DA12 DTC P0111: CHECK THE RESISTANCE OF THE IAT SENSOR

Note: Verify the engine is at operating temperature before taking the IAT reading.

Note: The intake air temperature should rise from ambient temperature as engine heat combines with the intake air causing the IAT sensor resistance to decrease from the ambient reading.

- MAF/IAT Sensor connector connected.
- Run the engine until the engine temperature stabilizes.
- Key in OFF position.
- MAF/IAT Sensor connector disconnected.
- Measure the resistance between:





Did the resistance change?

YES
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 On Board Diagnostic (OBD) Drive Cycle.

REPEAT the PCM self-test if necessary.

NO
INSTALL a new IAT sensor. Refer to Electronic Engine Controls.

CLEAR the DTCs. REPEAT the self-test.


-------------------------------------------------

DA13 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
INSTALL a new PCM.

REFER to Flash Electrically Erasable Programmable Read Only Memory (EEPROM) Flash Electrically Erasable Programmable Read Only Memory (EEPROM).

NO
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
pro multis · About Operation CHARM