Mitsubishi Lancer Evolution X. Manual - part 319

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-341

Check Condition

• Ignition switch is "ON" position.

Judgement Criterion

• Throttle position sensor (sub) 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 (main) fails.

.

OBD-II DRIVE CYCLE PATTERN

None.

.

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

• Throttle position sensor failed.
• Open or shorted throttle position sensor (sub) cir-

cuit, 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 15: 
Throttle Position Sensor (sub).

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 

15, Throttle Position Sensor (sub).

• Output voltage should be 4.0 volts or more when the 

throttle valve is fully closed with your finger.

• Output voltage should be 1.0 volt or less when the throt-

tle 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 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 11.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 3. Measure the sensor supply voltage at throttle 
position sensor harness side connector B-11.
(1) Disconnect the connector B-11 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 5 and ground.

• Voltage should be between 4.9 and 5.1 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.9 and 5.1 volts?

YES : Go to Step 7.
NO :  Go to Step 4.

STEP 4. Check harness connector B-09 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 11.

STEP 5. Check for open circuit and short circuit to ground 
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 6.
NO :  Repair it. Then go to Step 11.

1

6 5 4 3 2

AK203049

B-11 harness 
connector: 
component side

AG

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 6. Using scan tool MB991958, check data list item 15: 
Throttle Position Sensor (sub).
(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 

15, Throttle Position Sensor (sub).

• Output voltage should be 4.0 volts or more when the 

throttle valve is fully closed with your finger.

• Output voltage should be 1.0 volt or less when the throt-

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

register the ID code. Refer to GROUP 42B, ID Code 
Registration Necessity Judgment Table <Vehicles 
with KOS> 

P.42B-11

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 11.

STEP 7. Check harness connector B-09 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 8.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 11.

STEP 8. 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 9.
NO :  Repair it. Then go to Step 11.

STEP 9. Check for open circuit, short circuit to ground and 
harness damage between throttle position sensor 
connector B-11 (terminal No. 6) and ECM connector B-09 
(terminal No. 11).
Q: Is the harness wire in good condition?

YES : Go to Step 10.
NO :  Repair it. Then go to Step 11.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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STEP 10. 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 P0222 set?

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

register the ID code. Refer to GROUP 42B, ID Code 
Registration Necessity Judgment Table <Vehicles 
with KOS> 

P.42B-11

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 11.

NO :  The inspection is complete.

STEP 11. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the DTC has been deleted, read the DTC again.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0222 set?

YES : Retry the troubleshooting.
NO :  The inspection is complete.