DTC P0112, P0113 IAT SENSOR
[QG18DE]
DTC P0112, P0113 IAT SENSOR PFP:22630
Component Description UBS00B4M
The intake air temperature sensor is built-into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.
SEC266C
<Reference data>
Intake air temperature
Voltage* V Resistance kΩ
°C (°F)
-10(14) 4.43 7.9 - 9.3
25 (77) 3.32 1.9 - 2.1
80 (176) 1.23 0.31 - 0.37
*: These data are reference values and are measured between ECM terminal 34
(Intake air temperature sensor) and ground.
CAUTION: SEF012P
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM termi-
nals, such as the ground.
On Board Diagnosis Logic UBS00B4N
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0112 Intake air temperature An excessively low voltage from the sensor is
● Harness or connectors
0112 sensor circuit low input sent to ECM.
(The sensor circuit is open or shorted.)
P0113 Intake air temperature An excessively high voltage from the sensor ● Intake air temperature sensor
0113 sensor circuit high input is sent to ECM.
DTC Confirmation Procedure UBS00B4O
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-176, "Diagnostic Procedure"
.
SEF058Y
WITH GST
Follow the procedure “With CONSULT-II” above.
EC-174
DTC P0112, P0113 IAT SENSOR
[QG18DE]
Wiring Diagram UBS00B4P
EC
BBWA0676E
EC-175
DTC P0112, P0113 IAT SENSOR
[QG18DE]
Diagnostic Procedure UBS00B4Q
1. CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor (intake air temperature sensor
is built-into) sensor harness connector.
3. Turn ignition switch ON.
BBIA0150E
4. Check voltage between mass air flow sensor terminal 5 and
ground with CONSULT-II or tester.
Voltage: Approximately 5V
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
PBIB0066E
2. CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect TCM harness connector.
4. Check harness continuity between mass air flow sensor terminal 3 and ECM terminal 67, TCM terminal
42.
Refer to wiring diagram.
Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness for open or short between TCM and intake air temperature sensor
● Harness for open or short between ECM and intake air temperature sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-177, "Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace mass air flow sensor with intake air temperature sensor.
EC-176
DTC P0112, P0113 IAT SENSOR
[QG18DE]
5. CHECK INTERMITTENT INCIDENT A
Perform EC-139, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END EC
Component Inspection UBS00B4R
INTAKE AIR TEMPERATURE SENSOR C
1. Check resistance between intake air temperature sensor termi-
nals 3 and 5 under the following conditions.
Intake air temperature °C (°F) Resistance kΩ D
25 (77) 1.9 - 2.1
2. If NG, replace mass air flow sensor (with intake air temperature
sensor). E
F
SEC266C
SEF012P
J
EC-177
