Mitsubishi Lancer Evolution X. Manual - part 374

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-561

STEP 3. Measure the power supply voltage at throttle
actuator control motor relay harness side connector A-22X
(1) Disconnect the connector A-22X and measure at the

harness side.

(2) Measure the voltage between terminal No. 4 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 4.
NO : Repair it harness wire between battery and throttle

actuator control motor relay connector A-22X
(terminal No. 4) because of open circuit or short
circuit to ground. Then go to Step 14.

STEP 4. Measure the power supply voltage at throttle
actuator control motor relay harness side connector
A-22X.
(1) Disconnect the connector A-22X and measure at the

harness side.

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

• Voltage should be battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 6.
NO : Go to Step 5.

STEP 5. Check harness connector A-34X at MFI relay for
damage.
Q: Is the harness connector in good condition?

YES : Repair harness wire between MFI relay connector

A-34X (terminal No. 2) and throttle actuator control
motor relay connector A-22X (terminal No. 2)
because of open circuit or short circuit to ground.
Then go to Step 14.

NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 14.

3
4

AK604215 AD

A-22X harness
connector:
component side

AK604216

3
4

A-22X harness
connector:
component side

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

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STEP 6. Measure the power supply voltage at ECM harness
side connector B-10.
(1) Disconnect the connector B-10 and measure at the harness

side.

(2) Short-circuit the terminal No. 73 of the ECM harness

connector to the ground.

(3) Measure the voltage between terminal No. 84 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 7.
NO : Repair harness wire between throttle actuator control

motor relay connector A-22X (terminal No. 1) and
ECM connector B-10 (terminal No. 84) because of
open circuit or short circuit to ground. Then go to Step
14.

82 81 80 79 78 77 76 75 74 73 72 71

94 93 92 91 90 89 88 87 86 85 84 83

99 98 97 96 95

100

101

102

103

104

105

106

112

113

114

109 108

107

110

111

115

116

117

118

AK604217 AD

B-10 harness
connector:
component side

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-563

STEP 7. Measure the power supply voltage at ECM harness
side connector B-10.
(1) Disconnect the connector B-10 and measure at the harness

side.

(2) Short-circuit the terminals No. 73 and No. 84 of the ECM

harness connector to the ground.

(3) Measure the voltage between terminal No. 72 and ground.

• Voltage should be battery positive voltage.

Q: Is battery positive voltage (approximately 12 volts)

present?
YES : Go to Step 10.
NO : Go to Step 8.

STEP 8. Check for open circuit and short circuit to ground
between throttle actuator control motor relay connector
A-22X (terminal No. 3) and ECM connector B-10 (terminal
No. 72).
Q: Is the harness wire in good condition?

YES : Go to Step 9.
NO : Repair it. Then go to Step 14.

STEP 9. Check for harness damage between MFI relay
connector A-34X (terminal No. 2) and throttle actuator
control motor relay connector A-22X (terminal No. 2).
Q: Is the harness wire in good condition?

YES : Repair harness wire between throttle actuator control

motor relay connector A-22X (terminal No. 1) and
ECM connector B-10 (terminal No. 84) because of
harness damage. Then go to Step 14.

NO : Repair it. Then go to Step 14.

82 81 80 79 78 77 76 75 74 73 72 71

94 93 92 91 90 89 88 87 86 85 84 83

99 98 97 96 95

100

101

102

103

104

105

106

112

113

114

109 108

107

110

111

115

116

117

118

AK604218 AD

B-10 harness
connector:
component side

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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

YES : Go to Step 11.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 14.

STEP 11. Check for harness damage between battery and
throttle actuator control motor relay connector A-22X
(terminal No. 4).
Q: Is the harness wire in good condition?

YES : Go to Step 12.
NO : Repair it. Then go to Step 14.

STEP 12. Check for harness damage between throttle
actuator control motor relay connector A-22X (terminal No.
3) and ECM connector B-10 (terminal No. 72).
Q: Is the harness wire in good condition?

YES : Go to Step 13.
NO : Repair it. Then go to Step 14.

STEP 13. Using scan tool MB991958, read the diagnostic
trouble code (DTC).

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) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P0657 set?

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

P.42B-11

or GROUP 42C, ID Codes

Registration Judgment Table <Vehicles with WCM>

P.42C-9

. Then go to Step 14.

NO : 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

AC608435

Data link connector

MB991827

MB991824

MB991910

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