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Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 219

ENGINE DRIVEABILITY AND EMISSIONS

6E–117

Using the DVM and check the MAP sensor power
supply circuit.

1. Ignition “On”, engine “Off”.

2. Disconnect the MAP sensor connector.

3. Check the circuit for short to voltage circuit.

Was the DVM indicated specified value?

Approximately

5.0V

Go to Step 8

Go to Step 7

Repair the short to voltage circuit between the ECM
and MAP sensor.
Was the problem solved?

—

Verify repair

Go to Step 13

Using the DVM and check the MAP sensor signal
circuit.

1. Ignition “On”, engine “Off”.

2. Disconnect the MAP sensor connector.

3. Check the circuit for short to power supply circuit.

Was the DVM indicated specified value?

Less than 1V

Go to Step 9

Repair faulty

harness and

verify repair

Using the DVM and check the MAP sensor ground
circuit.

1. Ignition “On”, engine “Off”.

2. Disconnect the MAP sensor connector .

3. Check the circuit for short to power supply circuit.

Was the DVM indicated specified value?

Less than 1V

Go to Step 10

Repair faulty

harness and

verify repair

Step

Action

Value(s)

Yes

E85

E60(J1)

E85

6E–118

ENGINE DRIVEABILITY AND EMISSIONS

Using the DVM and check the MAP sensor ground
circuit.
Breaker box is available:

1. Ignition “Off”, engine “Off”.

2. Install the breaker box as type A. (ECM

disconnected) Ref. 6E-80.

3. Disconnect the MAP sensor connector.

4. Check the circuit for open circuit.

Was the problem found?

Breaker box is not available:

1. Ignition “Off”, engine “Off”.

2. Disconnect the MAP sensor connector and ECM

connector.

3. Check the circuit for open circuit.

Was the problem found?

—

Repair faulty

harness and

verify repair

Go to Step 11

Substitute a known good MAP sensor and recheck.
Was the problem solved?

—

Go to Step 12

Go to Step 13

Replace the MAP sensor.
Is the action complete?

—

Verify repair

—

Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?

—

Verify repair

Go to Step 14

Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Verify repair

—

Step

Action

Value(s)

Yes

E85

E60(J1)

ENGINE DRIVEABILITY AND EMISSIONS

6E–119

DIAGNOSTIC TROUBLE CODE (DTC) P0112 INTAKE AIR TEMPERATURE

SENSOR LOW INPUT

Condition for setting the DTC and action taken when the DTC sets

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.

Diagnostic Aids

Check for the following conditions:

• 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.

• Damaged harness - Inspect the wiring harness for

damage, short to ground, short to battery and open

Code

Type

DTC Name

DTC Setting Condition

Fail-Safe (Back Up)

P0112

Intake Air Temperature Sensor Low
Input

1. No DTC relating to VSS.
2. Vehicle speed is more than 25km/h.
3. Engine run time is longer than 120 sec-

onds.

4. IAT sensor output is more than 149°C.

The ECM uses 20°C condition as substi-
tute.

Intake
Air
Temperature(IAT)
Sensor

0.5
GRN

J2-1

0.5
YEL/
GRN

J2-22

0.5
GRN/
YEL

J2-20

0.5
BLU/
YEL

Engine
15A

Ignition
SW

Battery Voltage

J2-3

0.5
GRN/
WHT

J1-5

+5V

µP

Power
Steering
Pressure
SW

Evaporativ
Emission(EVAP)
Canistor
Purge
Valve
Solenoid

Engine
Control
Module
(ECM)

6E–120

ENGINE DRIVEABILITY AND EMISSIONS

circuit. 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.

Diagnostic Trouble Code (DTC) P0112

Intake Air Temperature Sensor Low Input

Step

Action

Value(s)

Yes

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

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

1. Connect the Tech 2.

2. Review and record the failure information.

3. Select “F0: Read DTC Infor By Priority” in “F0:

Diagnostic Trouble Code”.

Is the DTC P0112 stored as “Present Failure”?

—

Go to Step 3

Refer to

Diagnostic Aids

and Go to Step

1. Using the Tech2, ignition “On” and engine “Off”.

2. Select “Clear DTC Information” with the Tech2 and

clear the DTC information.

3. Operate the vehicle and monitor the “F5: Failed

This Ignition” in “F2: DTC Information”.

Was the DTC P0112 stored in this ignition cycle?

—

Go to Step 4

Refer to

Diagnostic Aids

and Go to Step

Check for poor/faulty connection at the IAT sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 5

Remove the IAT sensor and visually check.
Was the problem found?

—

Go to Step 8

Go to Step 6

C56(J2)

C121

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