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Mitsubishi Lancer Evolution X. Manual - part 284

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-201

DTC P0122: Throttle Position Sensor (main) Circuit Low Input

CIRCUIT OPERATION

• A 5-volt power supply is applied on the throttle

position sensor (main) power terminal (terminal
No. 5) from the ECM (terminal No. 12).

• A voltage that is according to the throttle opening

angle is sent to the ECM (terminal No. 10) from
the throttle position sensor (main) output terminal
(terminal No. 4).

AK603950

3 4 5 6 7 8 9 10 11 12 13 14 15 16

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

1 2 3 4 5

5 V

THROTTLE POSITION SENSOR (MAIN) CIRCUIT

THROTTLE POSITION
SENSOR (MAIN)

B-09

HALL IC

YELLO

-GRA

YELLO

-RED

GRA

-RED

ENGINE
CONTROL
MODULE

B-11

(MU805200)

AK704227

Connector: B-09

ECM

B-09 (GR)

AK704247AB

Connector: B-11

B-11 (B)

Radiator cap

Throttle body assembly
(incorporating throttle
position sensor)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-202

• The ground terminal (terminal No. 3) is grounded

with ECM (terminal No. 13).

TECHNICAL DESCRIPTION

• The throttle position sensor (main) outputs volt-

age which corresponds to the throttle valve open-
ing angle.

• The ECM checks whether the voltage is within a

specified range.

DESCRIPTIONS OF MONITOR METHODS

Throttle position sensor (main) output voltage is out

of specified range.

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)

• Not applicable

DTC SET CONDITIONS
Logic Flow Chart

Malfunction

End

Good

Output voltage <= 0.2V

Output voltage >= 4.8V

AK604318

Start

Yes

Continuous

failure for 0.3sec

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-203

Check Condition

• Ignition switch is "ON" position.

Judgement Criterion

• Throttle position sensor (main) output voltage

should be 0.2 volt or less for 0.3 second.

FAIL-SAFE AND BACKUP FUNCTION

• Throttle opening degree is restricted.
• Throttle opening degree position is in default

position if throttle position sensor (sub) fails.

OBD-II DRIVE CYCLE PATTERN

None.

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

• Throttle position sensor failed.
• Shorted throttle position sensor (main) circuit,

harness damage, or connector damage.

• ECM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

• MB991658: Test Harness

STEP 1. Using scan tool MB991958, check data list item 13:
Throttle Position Sensor (main).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Detach the intake air hose at the throttle body.
(4) Disconnect the connector of the throttle position sensor.
(5) Use test harness special tool (MB991658) to connect only

terminals No. 3, No. 4, No. 5, and No. 6.

(6) Set scan tool MB991958 to the data reading mode for item

13, Throttle Position Sensor (main).

• Output voltage should be between 0.3 and 0.7 volt when

the throttle valve is fully closed with your finger.

• Output voltage should be 4.0 volts or more when the

throttle valve is fully open with your finger.

(7) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points − How to

Cope with Intermittent Malfunctions

P.00-15

NO : Go to Step 2.

STEP 2. Check harness connector B-11 at throttle position
sensor and harness connector B-09 at ECM 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 7.

AC608435

Data link connector

MB991827

MB991824

MB991910

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-204

STEP 3. Check for harness damage between throttle
position sensor connector B-11 (terminal No. 5) and ECM
connector B-09 (terminal No. 12).
Q: Is the harness wire in good condition?

YES : Go to Step 4.
NO : Repair it. Then go to Step 7.

STEP 4. Check for short circuit to ground and harness
damage between throttle position sensor connector B-11
(terminal No. 4) and ECM connector B-09 (terminal No. 10).
Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO : Repair it. Then go to Step 7.

STEP 5. Using scan tool MB991958, check data list item 13:
Throttle Position Sensor (main).
(1) Turn the ignition switch to the "ON" position.
(2) Detach the intake air hose at the throttle body.
(3) Disconnect the connector of the throttle position sensor.
(4) Use test harness special tool (MB991658) to connect only

terminals No. 3, No. 4, No. 5, and No. 6.

(5) Set scan tool MB991958 to the data reading mode for item

13, Throttle Position Sensor (main).

• Output voltage should be between 0.3 and 0.7 volt when

the throttle valve is fully closed with your finger.

• Output voltage should be 4.0 volts or more when the

throttle valve is fully open with your finger.

(6) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points − How to

Cope with Intermittent Malfunctions

P.00-15

NO : Go to Step 6.

STEP 6. Replace the throttle body assembly.
(1) Replace the throttle body assembly.
(2) Turn the ignition switch to the "ON" position.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0122 set?

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

KOS>

P.42B-11

or GROUP 42C, Diagnosis − ID

Codes Registration Judgment Table <Vehicles with
WCM>

P.42C-9

. Then go to Step 7.

NO : The inspection is complete.

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