Mitsubishi Galant (2004+). Manual - part 1229

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-609

DIAGNOSIS

Required Special Tools:

• MB991709: Test Harness Set

• MB991923: Power Plant ECU Check Harness

STEP 1. Using the oscilloscope, check the camshaft 
position sensor.

(1) Disconnect the camshaft position sensor connector B-106, 

and connect test harness special tool (MB991709) between 

the separated connectors (All terminals should be 
connected).

(2) Connect the oscilloscope probe to the camshaft position 

sensor side connector terminal No. 2.
NOTE: When measuring with the PCM side connector, dis-
connect the all PCM connectors and connect check har-
ness special tool (MB991923) between the separated 
connectors. then connector the osilloscope probe to the 
check harness connector terminal No. 104.

(3) Start the engine and run at idle.

(4) Check the waveform.

• The waveform should show a pattern similar to the illus-

tration.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?

YES : Go to Step 2..
NO :  Go to Step 4.

STEP 2. Check harness connector B-106 at camshaft 
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 20.

1

2

3

AK303130

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

CAMSHAFT POSITION 
SENSOR

B-106 (B)

CONNECTOR: B-106

AK102976AB

1 2 3

CAMSHAFT POSITION
SENSOR CONNECTOR

OSCILLOSCOPE

MB991709

AK302213AB

2 ENGINE REVOLUTIONS

NORMAL WAVEFORM

5V

1

2

3

AK303130

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

CAMSHAFT POSITION 
SENSOR

B-106 (B)

CONNECTOR: B-106

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-610

STEP 3. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function 

− OBD-II Drive Cycle − Procedure 6 − 

Other Monitor 

P.13B-5

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0340 set?

YES : Replace the PCM. Then go to Step 20.
NO :  It can be assumed that this malfunction is intermittent. 

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

P.00-6

.

STEP 4. Check harness connector B-106 at camshaft 
position sensor 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 20.

STEP 5. Measure the sensor supply voltage at camshaft 
position sensor connector B-106.

(1) Disconnect the connector B-106 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 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 10.
NO :  Go to Step 6.

1

2

3

AK303130

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

CAMSHAFT POSITION 
SENSOR

B-106 (B)

CONNECTOR: B-106

1

2

3

AK303130

HARNESS 
CONNECTOR: 
COMPONENT SIDE

AB

CAMSHAFT POSITION 
SENSOR

B-106 (B)

CONNECTOR: B-106

AK303132

B-106 HERNESS 
CONNECTOR: 
COMPONENT SIDE

1

2

3

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-611

STEP 6. Measure the sensor supply voltage at PCM 
connector B-22 by using power plant ECU check harness 
special tool MB991923.

(1) Disconnect the all PCM connectors and connect power 

plant ECU check harness special tool MB991923 between 
the separated connectors.

(2) Disconnect the camshaft position sensor connector B-106.
(3) Turn the ignition switch to the "ON" position.

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

AK202956

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

AB

POWER PLANT ECU 
CHECK HARNESS CONNECTOR

MB991923

PCM

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-612

(4) Measure the voltage between terminal No. 104 and ground.

• Voltage should be between 4.9 and 5.1 volts.

(5) 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 8.

STEP 7. Check harness connector B-22 at PCM for 
damage.

Q: Is the harness connector in good condition?

YES : Repair harness wire between camshaft position 

sensor connector B-106 (terminal No. 2) and PCM 
connector B-22 (terminal No. 104) because of open 
circuit. Then go to Step 20.

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

Connector Inspection 

P.00E-2

. Then go to Step 20.

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

AK202946AB

POWER PLANT ECU 
CHECK HARNESS 
CONNECTOR 

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