Daewoo Matiz (2003 year). Manual - part 39

1F – 66  ENGINE CONTROLS

MAA1F100

DIAGNOSTIC TROUBLE CODE (DTC) – P0112 INTAKE AIR TEMPERATURE

SENSOR LOW VOLTAGE

Circuit Description

The Intake Air Temperature (IAT) Sensor uses a therm-
istor to control the signal voltage to the engine control
module (ECM). The ECM supplies a 5 volt reference
voltage and a ground to the sensor. When the air is cold,
the resistance is high ; therefore IAT sensor signal volt-
age will be high. If the intake air is warm, resistance is
low ; therefore the IAT sensor signal voltage will be low.

Conditions for Setting the DTC

D

The engine rum time is greater than 3 seconds.

D

IAT voltage is less than 0.01V

Action Taken when the DTC Sets

D

Emission related.

D

“Armed” after two trip with a fail.

D

“Disarmed” after one trip with a pass.

D

MIL on if failure is detected in three consecutive trips.

D

Stores a History DTC on the third consecutive with a
fail (The DTC will be armed after the second fail).

D

Stores a Freeze Frame on the third consecutive trip
with a fail (if empty).

D

The ECM  will default to 60

°

C(140

°

F)for intake air

temperature. The scan tool will not show the de-
faulted value.

Conditions for Clearing the MIL/DTC

D

The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.

D

A history DTC will clear after 40 consecutive warm up
cycles without a fault.

D

DTC(s) can be cleared by using the scan tool.

Diagnostic aids

If the vehicle is at ambient temperature, compare the
IAT sensor to the engine coolant temperature(ECT) sen-
sor. The IAT sensor and the ECT sensor should be rela-
tively close to each other. Use the temperature vs.
Resistance Values table to evaluate the possibility of a
skewed sensor. Refer to “Temperature vs. Resistance”
in this Section.

ENGINE CONTROLS  1F – 67

DTC P0112 – Intake Air Temperature Sensor Low Voltage

Step

Action

Value(s)

Yes

No

1

Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?

–

Go to Step 2

Go to

“On-Board
Diagnostic

System Check”

2

1. Connect the scan tool to the data link

connector(DLC).

2. Run the engine until it reaches operating

temperature.

Does the scan tool show the IAT sensor reading
within the value specified?

15–80

°

C

Go to

“Diagnostic

Aids”

Go to Step 3

3

1. Turn the ignition switch to LOCK.
2. Disconnect the IAT sensor connector.
3. Turn the ignition switch to ON.
Does the scan tool show the IAT sensor reading
within the value specified?

≤

-30

°

C

Go to Step 4

Go to Step 5

4

Check for a faulty connector or terminals at the IAT
sensor connector.
Is the problem found?

–

Go to Step 7

Go to Step 6

5

Check for wire for a short to ground between the IAT
connector terminal 1 and the ECM connector
terminal 79.
Is the problem found?

–

Go to Step 7

Go to Step 6

6

Check for wire for a short to ECM reference voltage
between the IAT sensor connector terminal 2 and
the ECM connector terminal 47.
Is the problem found?

4.5–5.0V

Go to Step 7

Go to Step 9

7

1. Turn the ignition switch to LOCK.
2. Repair the wire or the connector terminal as

needed.

3. Clear any DTCs from the ECM.
4. Run the engine until it reaches operating

temperature.

5. Perform the diagnostic system check.
Is the repair complete?

–

System OK

–

8

1. Turn the ignition switch to LOCK.
2. Replace the IAT sensor.
3. Clear any DTCs from the ECM.
4. Run the engine until it reaches operating

temperature.

5. Perform the diagnostic system check.
Is the repair complete?

–

System OK

–

9

1. Turn the ignition switch to LOCK.
2. Replace the engine control module(ECM).
3. Run the engine until it reaches operating

temperature.

4. Perform the diagnostic system check.
Is the repair complete?

–

Go to Step 10

–

10

Check if any additional DTCs are set.
Are any DTCs displaced that have not been
diagnosed?

–

Go to

applicable DTC

table

System OK

1F – 68  ENGINE CONTROLS

MAA1F100

DIAGNOSTIC TROUBLE CODE (DTC) – P0113 INTAKE AIR TEMPERATURE

SENSOR HIGH VOLTAGE

Circuit Description

The Intake Air Temperature (IAT) Sensor uses a therm-
istor to control the signal voltage to the engine control
module (ECM). The ECM supplies a 5 volt reference
voltage and a ground to the sensor . when the air is cold,
the resistance is high ; therefore IAT sensor signal volt-
age will be high. If the intake air is warm, resistance is
low ; therefore the IAT sensor signal voltage will be low.

Conditions for Setting the DTC

D

The engine rum time is greater than 3 seconds.

D

IAT voltage is greater than 4.99V.

Action Taken when the DTC Sets

D

Emission related.

D

“Armed” after two trip with a fail.

D

“Disarmed” after one trip with a pass.

D

MIL on if failure is detected in three consecutive trips.

D

Stores a History DTC on the third consecutive with a
fail (The DTC will be armed after the second fail).

D

Stores a Freeze Frame on the third consecutive trip
with a fail (if empty).

D

The ECM will default to last valid value for intake air
temperature. The scan tool will not show the de-
faulted value.

Conditions for Clearing the MIL/DTC

D

The MIL will turn off after four consecutive ignition
cycles in which the diagnostic runs without a fault.

D

A history DTC will clear after 40 consecutive warm up
cycles without a fault.

D

DTC(s) can be cleared by using the scan tool.

Diagnostic Aids

If the vehicle is at ambient temperature, compare the
IAT sensor to the engine coolant temperature (ECT)
sensor. The IAT sensor and the ECT sensor should be
relatively close to each other.

Use the temperature vs. Resistance Values table to
evaluate the possibility of a skewed sensor. Refer to
“Temperature vs. Resistance” in this Section.

ENGINE CONTROLS  1F – 69

DTC P0113 – Intake Air Temperature Sensor High Voltage

Step

Action

Value(s)

Yes

No

1

Perform an Euro On-Board Diagnostic (EOBD)
System Check.
Is the system check complete?

–

Go to Step 2

Go to

“On-Board
Diagnostic

System Check”

2

1. Connect the scan tool to the data link connector

(DLC).

2. Run the engine unit it reaches operating

temperature.

Does the scan tool show the intake air temperature
(IAT) sensor reading within the value specified?

15~80

°

C

(10~176

°

F)

Go to

“Diagnostic

Aids”

Go to Step 3

3

1. Turn the ignition switch to LOCK.
2. Disconnect the IAT sensor connector.
3. Jumper to IAT sensor connector terminals.
4. Turn the ignition switch to ON.
Does the scan tool show the IAT sensor reading the
value specified?

180

°

C

(356

°

F)

Go to Step 4

Go to Step 5

4

Check for a faulty connector or terminals 1 and 2 of
the IAT sensor connector.
Is the problem found?

–

Go to Step 10

Go to Step 9

5

Measure the voltage between terminals 1 and 2 of
IAT sensor connector.
Does the voltage measure within the value
specified?

4.5~5.5V

Go to Step 11

Go to Step 6

6

Measure the voltage between the IAT sensor
connector terminal 2 and the battery
ground(negative) post.
Does the voltage measure within the value
specified?

4.5~5.5V

Go to Step 7

Go to Step 8

7

1. Turn the ignition switch to LOCK.
2. Check for an open or short to battery voltage in

the wire between the IAT sensor connector
terminal 2 and the engine control module(ECM)
connector terminal 47.

Is the problem found?

–

Go to Step 10

Go to Step 11

8

1. Turn the ignition switch to LOCK.
2. Check for an open or short to battery voltage in

the wire between the IAT sensor connector
terminal 1 and the ECM connector terminal 79.

Is the problem found?

–

Go to Step 10

Go to Step 11

9

1. Turn the ignition switch to LOCK
2. Replace the IAT sensor.
3. Clear any DTCs from the ECM.
4. Perform the diagnostic system check.
Is the repair complete?

–

System OK

–

10

1. Turn the ignition switch to LOCK.
2.Repair the wire of the connector terminals as

needed.

3. Clear any DTCs from the ECM.
4. Perform the diagnostic system check.
Is the repair complete?

–

System OK

–