Mitsubishi Galant 9G. Manual — part 966

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-164

DTC SET CONDITIONS
Logic Flow Chart

.

Check Condition

• Ignition switch is "ON" position.

Judgement Criteria

• Throttle position sensor (main) output voltage

should be 0.35 volt or less for 0.5 second.

.

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 (main)

circuit, harness damage, or connector damage.

• PCM failed.

START

YES

YES

YES

NO

NO

NO

CONTINUOUS

FAILURE FOR 0.5sec

MALFUNCTION

END

GOOD

OUTPUT VOLTAGE

< =0.35V

OUTPUT VOLTAGE > =4.8V

AK302389

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

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DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (MUT-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 79:
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

79, 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 between 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.00-14

.

NO : Go to Step 2.

STEP 2. Check harness connector B-06 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.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

2 1

6 5 4 3

AK303044

HARNESS
CONNECTOR:
COMPONENT SIDE

B-06 (B)

CONNECTOR: B-06

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

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STEP 3. Measure the sensor supply voltage at throttle
position sensor harness side connector B-06.

(1) Disconnect the connector B-06 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-22 at PCM 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.

2 1

6 5 4 3

AK303044

HARNESS
CONNECTOR:
COMPONENT SIDE

B-06 (B)

CONNECTOR: B-06

AB

1

6 5 4 3 2

AK303045

B-06 HARNESS
CONNECTOR:
COMPONENT SIDE

AB

AK303016

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTOR: B-22

B-22 (B)

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

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STEP 5. Check for open circuit and short circuit to ground
between throttle position sensor connector B-06 (terminal
No. 5) and PCM connector B-22 (terminal No. 94).

Q: Is the harness wire in good condition?

YES : Go to Step 6.
NO : Repair it. Then go to Step 11.

2 1

6 5 4 3

AK303044

HARNESS
CONNECTOR:
COMPONENT SIDE

B-06 (B)

CONNECTOR: B-06

AB

AK303016

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTOR: B-22

B-22 (B)

PCM

AB

HARNESS CONNECTOR:
COMPONENT SIDE

AIR CLEANER