Mitsubishi Evolution X. Manual — part 279

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-93

CIRCUIT OPERATION

• Approximately 5 volts are applied to the intake air

temperature sensor 2 output terminal (terminal
No. 1) from the ECM (terminal No. 98) via the
resistor in the ECM. The ground terminal (termi-
nal No. 2) is grounded with ECM (terminal No.
97).

• The intake air temperature sensor 2 is a negative

temperature coefficient type of resistor. When the
intake air temperature rises, the resistance
decreases.

• The intake air temperature sensor 2 output volt-

age increases when the resistance increases and
decreases when the resistance decreases.

TECHNICAL DESCRIPTION

• The intake air temperature sensor 2 converts the

intake air temperature to a voltage.

• The ECM checks whether this voltage is within a

specified range.

DESCRIPTIONS OF MONITOR METHODS

Intake air temperature sensor 2 output voltage does

not change when specified go/stop operations
are repeated.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS
(Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be

normal)

• Engine coolant temperature sensor

AK704235 AB

Connector: B-10

ECM

B-10 (GR)

AK704400

Connector: B-16

B-16 (B)

Intake air temperature
sensor 2

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-94

DTC SET CONDITIONS
Logic Flow Chart

Check Conditions

• Engine coolant temperature is higher than 76° C

(169

° F).

• Repeat 2 or more times: drive

, stop

Drive

: vehicle speed higher than 50 km/h (31

mph) lasting a total of 60 seconds or more.

Stop

: vehicle speed lower than 1.5 km/h (1.0

mph) lasting 30 seconds or more.

Judgement Criterion

• Changes in the intake air temperature is lower

than 1

° C (1.8° F).

FAIL-SAFE AND BACKUP FUNCTION

• Control as if the intake air temperature in the

intake manifold is 25

° C.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Pattern 7

P.13A-9

TROUBLESHOOTING HINTS (The most
likely causes for this code to be set are:)

• Intake air temperature sensor 2 failed.

• Harness damage or connector damage.

• ECM failed.

End

Malfunction

Yes

Go/stop operation

for specified times

Intake air temp.

changes

Monitoring

conditions

Good

Start

AK604314

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-95

DIAGNOSIS

STEP 1. Check the intake air temperature sensor 2.
(1) Disconnect the intake air temperature sensor 2 connector

B-16.

(2) Measure the resistance between intake air temperature

sensor 2 side connector terminal No. 1 and No. 2.

(3) Measure resistance while heating the sensor using a hair

drier.

Standard value:

− 18 kΩ [at −20° C (−4° F)]

5.1

− 6.9 kΩ [at 0° C (32° F)]

2.0

− 3.0 kΩ [at 20° C (68° F)]

0.9

− 1.5 kΩ [at 40° C (104° F)]

0.40

− 0.78 kΩ [at 60° C (140° F)]

0.23

− 0.42 kΩ [at 80° C (176° F)]

Q: Is the measured resistance at the standard value?

YES : Go to Step 2.
NO : Replace the intake air temperature sensor 2. Then go

to Step 8.

STEP 2. Check harness connector B-16 at the intake air
temperature sensor 2 for damage.
Q: Is the harness connector in good condition?

YES : Go to Step 3.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 8.

AK704080

Intake air temperature
sensor 2 connector

AK403661 AE

Intake air temperature
sensor 2

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-96

STEP 3. Check the continuity at intake air temperature
sensor 2 harness side connector B-16.
(1) Disconnect the connector B-16 and measure at the harness

side.

(2) Check for the continuity between terminal No. 2 and

ground.

• Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 6.
NO : Go to Step 4.

STEP 4. Check harness connector B-10 at ECM for
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 5.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 8.

STEP 5. Check for harness damage between intake air
temperature sensor 2 connector B-16 (terminal No. 2) and
ECM connector B-10 (terminal No. 97).
NOTE: Check harness after checking intermediate connector
A-13. If intermediate connector is damaged, repair or replace it.
Repair to GROUP 00E, Harness Connector Inspection

P.00E-2

. Then go to Step 8.

Q: Is the harness wire in good condition?

YES : Replace the ECM. When the ECM is replaced,

P.42B-12

or GROUP 42C, ID Codes

Registration Judgment Table <Vehicles with WCM>

P.42C-9

. Then go to Step 8.

NO : Repair it. Then go to Step 8.

STEP 6. Check harness connector B-10 at ECM for
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 7.
NO : Repair or replace it. Refer to GROUP 00E, Harness