Mitsubishi Galant (2004+). Manual — part 1140

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-253

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13B-5

.

.

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

• Right bank heated oxygen sensor (rear) failed.

• Open or shorted circuit in right bank heated oxy-

gen sensor (rear) output line or harness damage.

• Open circuit in right bank heated oxygen sensor

(rear) ground line or harness damage.

• Connector damage.

• PCM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• MB991316: Test Harness

• MB991923: Power Plant ECU Check Harness

STEP 1. Using scan tool MB991958, check data list item 69:
Heated Oxygen Sensor Bank 1, Sensor 2 (right rear).

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) Start the engine and run at idle.

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

69, Heated Oxygen Sensor Bank 1, Sensor 2 (right rear).

• Warming up the engine. When the engine is revved, the

output voltage should repeat 0 volt and 0.6 to 1.0 volt
alternately.

(4) 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

P.00-6

.

NO : Go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-254

STEP 2. Measure the sensor output voltage at right bank
heated oxygen sensor (rear) connector B-08 by
backprobing

(1) Do not disconnect the connector B-08.
(2) Start the engine and run at idle.

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

backprobing.

• Warming up the engine. When the engine is revved, the

output voltage should repeat 0 volt and 0.6 to 1.0 volt
alternately.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage within the specified range?

YES : Go to Step 3.
NO : Go to Step 7.

AK303064

1

2

3

4

THROTTLE BODY

RIGHT BANK
HEATED OXYGEN
SENSOR (REAR)

CONNECTOR: B-08

B-08 (GR)

AB

HARNESS
CONNECTOR:
COMPONENT SIDE

1 2

4

3

AK303065

B-08 HARNESS
CONNECTOR:
HARNESS SIDE

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-255

STEP 3. Measure the sensor output 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) Start the engine and run at idle.

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-256

(3) Measure the voltage between terminal No. 97 and ground.

• Warming up the engine. When the engine is 2,500 r/min,

the output voltage should repeat 0 volt and 0.6 to 1.0
volt alternately.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage within the specified range?

YES : Go to Step 4.
NO : Go to Step 6.

104

96

94

95

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

AK203101AB

POWER PLANT ECU
CHECK HARNESS
CONNECTOR