Opel Frontera UE. Manual - part 200

6E1–98

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0112 INTAKE AIR TEMPERATURE (IAT)

SENSOR CIRCUIT LOW INPUT 

D06RX116

Circuit Description

The intake air temperature (IAT) sensor is a thermistor
which measures the temperature of the air entering the
engine. The engine control module (ECM) applies 5 volts
through a pull–up resistor to the IAT sensor. When the
intake air is cold, the sensor resistance is high and the
ECM will monitor a high signal voltage on the IAT signal
circuit. If the intake air is warm, the sensor resistance is
lower, causing the ECM to monitor a lower voltage.
Diagnostic Trouble Code P0112 will set when the ECM
detects an excessively low signal voltage (short to
ground) on the intake air temperature sensor signal
circuit.  DTC P0112 is a Type A Code.

Conditions for Setting the DTC

D

The engine has been running for over 2 minutes.

D

Vehicle speed is greater than 48 km/h (30 mph).

D

IAT signal voltage less than 0.10 volts for a total of 12.5
seconds over a 25–second period of time.

The above conditions are met for at least 2 seconds.

Action Taken When the DTC Sets

D

The ECM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

D

The ECM will use a default IAT valve based on ECM
inputs and engine run time.

D

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.

Conditions for Clearing the MIL/DTC

D

The ECM will turn the MIL OFF on the third consecutive
trip cycle during which the diagnostic has been run and
the fault condition is no longer present.

D

A history DTC P0112 will clear after 40 consecutive
warm–up cycles have occurred without a fault.

D

DTC P0112 can be cleared by using the Scan Tool’s
”Clear Info” function.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – Inspect harness connectors
for backed–out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal–to–wire connection.

D

Damaged harness – Inspect the wiring harness for
damage, shorts to ground, shorts to battery and open
circuits. If the harness appears to be OK, observe the
IAT display on the Tech 2 while moving connectors and
wiring harnesses related to the IAT sensor. A change
in the IAT display will indicate the location of the fault.

If Diagnostic Trouble Code P0112 cannot be duplicated,
the information included in the Failure Records data can
be useful in determining vehicle mileage since the
Diagnostic Trouble Code was last set.

6E1–99

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Verifies that the fault is present.

3. If Diagnostic Trouble Code P0112 can be repeated

only by duplicating the Failure Records condition,
refer to the Temperature vs. Resistance Value table.

The table may be used to test the IAT sensor at
various temperatures to evaluate the possibility of
a ”shifted” sensor that may be stored above or
below a certain temperature. If this is the case,
replace the IAT sensor. If the IAT sensor appears
to be OK, the fault is intermittent; refer to
Diagnostic Aids.

Intake Air Temperature Sensor

°

C

°

F

OHMS

Temperature vs. Resistance Values (approximate)

100

212

177

80

176

332

60

140

667

45

113

1188

35

95

1802

25

77

2796

15

59

4450

5

41

7280

–5

23

12300

–15

5

21450

–30

–22

52700

–40

–40

100700

6E1–100

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0112 Intake Air Temperature (IAT) Sensor Circuit Low Input 

 

Step

Action

Value(s)

Yes

No

1

Was the ”On–Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2 

Go to OBD

System

Check 

2

1. Ignition ON, engine OFF.
2. Using a Tech 2, monitor the intake air temperature

(IAT).

Is the intake air temperature greater than the specified
value?

148

°

C

(283

°

F)

Go to Step 4 

Go to Step 3 

3

1. Ignition ON, engine OFF. Review and record Tech 2

Failure Records data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor the ”DTC” info for

Diagnostic Trouble Code P0112.

Does the Tech 2 indicate DTC P0112 failed this
ignition?

—

Refer to Test

Description 

Refer to

Diagnostic

Aids 

4

1. Ignition OFF.
2. Disconnect the IAT sensor electrical connector.
3. Ignition ON.
4. Observe the intake air temperature on the Tech 2.

Is the intake air temperature below the specified value?

–38

°

C

(–36

°

F)

Go to Step 6 

 Go to Step 5 

5

1. Ignition OFF.
2. Disconnect the ECM electrical connectors.
3. Check the IAT sensor signal circuit for a short to

ground.

Is the IAT sensor signal circuit shorted to ground?

—

Verify Repair

Go to Step 7 

6

Replace the IAT sensor.

Is the action complete?

—

Verify Repair

—

7

Replace the ECM.

Is the action complete?

—

Verify Repair

—

6E1–101

X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0113 INTAKE AIR TEMPERATURE (IAT)

SENSOR CIRCUIT HIGH INPUT

D06RX118

Circuit Description

The intake air temperature (IAT) sensor is a thermistor
which measures the temperature of the air entering the
engine. The engine control module (ECM) applies 5 volts
through a pull–up resistor to the IAT sensor. When the
intake air is cold, the sensor resistance is high and the
ECM will monitor a high signal voltage on the IAT signal
circuit. If the intake air is warm, the sensor resistance is
lower causing the ECM to monitor a lower voltage.
Diagnostic Trouble Code P0113 will set when the ECM
detects an excessively high signal voltage on the intake
air temperature sensor signal circuit.  DTC P0113 is a
Type A Code.

Conditions for Setting the DTC

D

The engine has been running for over 4 minutes.

D

Vehicle speed is less than 32 km/h (20 mph).

D

ECT signal temperature is above 60

°

C (140

°

F).

D

Mass air flow is less than 20g/second.

D

IAT signal voltage almost 5 volts which indicates an
intake air temperature less than –39

°

C (–38

°

F) for a

total of 12.5 seconds over a 25–second period.

Action Taken When the DTC Sets

D

The ECM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

D

The ECM will use a default IAT valve based on ECM
inputs and engine run time.

D

The ECM will store conditions which were present
when the Diagnostic Trouble Code was set as Freeze
Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC

D

The ECM will turn the MIL OFF on the third consecutive
trip cycle during which the diagnostic has been run and
the fault condition is no longer present.

D

A history Diagnostic Trouble Code P0113 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.

D

Diagnostic Trouble Code P0113 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at ECM – Inspect harness connectors
for backed–out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal–to–wire connection.

D

Damaged harness – Inspect the wiring harness for
damage, shorts to ground, shorts to battery positive,
and open circuits. If the harness appears to be OK,
observe the IAT display on the Tech 2 while moving
connectors and wiring harnesses related to the IAT
sensor. A change in the IAT display will indicate the
location of the fault.

If Diagnostic Trouble Code P0113 cannot be duplicated,
the information included in the Failure Records data can