Mitsubishi Galant. Manual — part 254

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-241

CIRCUIT OPERATION

•

The crankshaft position sensor power is supplied
from the MFI relay (terminal 1), and the ground is
provided on the vehicle body.

•

A 5-volt voltage is applied on the crankshaft
position sensor output terminal (terminal 2) from
the PCM (terminal 45). The crankshaft position
sensor generates a pulse signal when the output
terminal is opened and grounded.

TECHNICAL DESCRIPTION

•

The crankshaft position sensor detects the crank
angle (position) of each cylinder, and converts
that data to pulse signals, which are then input to
the PCM.

•

When the engine is running, the crankshaft
position sensor outputs a pulse signal.

•

The PCM checks whether pulse signal is input
while the engine is cranking.

DTC SET CONDITIONS

Check Conditions

•

Engine is being cranked.

Judgment Criteria

•

Crankshaft position sensor output voltage has not
changed (no pulse signal is input) for 2 seconds.

Check Conditions, Judgment Criteria

•

Normal signal pattern has not been input for
cylinder identification from the crankshaft position
sensor signal and camshaft position sensor
signal for 2 seconds.

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

•

Crankshaft position sensor failed.

•

Open or shorted crankshaft position sensor
circuit, or loose connector.

•

PCM failed.

DIAGNOSIS

Required Special Tools
MB991502: Scan Tool (MUT-II)

AK000617

CONNECTOR:B-20

AD

AK000555AB

CONNECTOR : A-21X

MFI RELAY

AK000280

CONNECTOR : C-40

PCM

AV

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-242

STEP 1. Using scan tool MB991502, check data list item 22:
Crankshaft Position Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991502 to the data reading mode for item

22, Crankshaft Position Sensor.

•

The tachometer and engine speed indicated on the scan
tool should much.

(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.00-8

).

NO : Go to Step 2.

STEP 2. Using the oscilloscope, check the crankshaft
position sensor.
(1) Do not disconnect the crankshaft position sensor connector

B-20.

(2) Connect the oscilloscope probe to terminal 2 of the

crankshaft position sensor by backprobing.

NOTE: Connect the oscilloscope probe to terminal 45 by
backprobing when measuring with the PCM connector.

(3) Start the engine and run at idle.
(4) Check the waveform.

•

The waveform should show a pattern similar to the
illustration.

(5) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the waveform normal?

YES : Go to Step 3.
NO : Go to Step 5.

AC003081 AB

16 PIN

MB991502

AKX01500

CRANKSHAFT POSITION
SENSOR CONNECTOR

OSCILLOSCOPE

1 2

3

AB

OSCILLO-
SCOPE
PROBE

AKX01559AB

NORMAL WAVEFORM

2 ENGINE REVOLUTIONS

5V

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-243

STEP 3. Check connector B-20 at the crankshaft position
sensor for damage.
Q: Is the connector in good condition?

YES : Go to Step 4.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 20.

STEP 4. Using scan tool MB991502, check data list item 22:
Crankshaft Position Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK"(OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to the data reading mode for item

22, Crankshaft Position Sensor.

•

The tachometer and engine speed indicated on the scan
tool should much.

(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.00-8

).

NO : Replace the PCM. Then go to Step 20.

STEP 5. Check connector B-20 at the crankshaft position
sensor for damage.
Q: Is the connector in good condition?

YES : Go to Step 6.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 20.

AK000617

CONNECTOR:B-20

AD

AC003081 AB

16 PIN

MB991502

AK000617

CONNECTOR:B-20

AD

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-244

STEP 6. Check the sensor supply voltage at crankshaft
position sensor harness side connector B-20.
(1) Disconnect the connector B-20 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 2 and ground.

•

Voltage should be between 4.8 and 5.2 volts

(4) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the voltage normal?

YES : Go to Step 11.
NO : Go to Step 7.

STEP 7. Check the sensor supply voltage at PCM
connector C-40 by backprobing
(1) Do not disconnect the PCM connector C-40.
(2) Disconnect the crankshaft position sensor connector B-20.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between terminal 45 and ground by

backprobing.

•

Voltage should be between 4.8 and 5.2 volts.

(5) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the voltage normal?

YES : Go to Step 8.
NO : Go to Step 9.

STEP 8. Check connector C-40 at PCM for damage.
Q: Is the connector in good condition?

YES : Repair it because of open circuit between crankshaft

position sensor connector B-20 terminal 2 and PCM
connector C-40 terminal 45. 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.

STEP 9. Check connector C-40 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 10.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 20.

AKX01416 AC

2 1

3

B-20 HARNESS
SIDE CONNECTOR

AK000297

C-40 CONNECTOR
HARNESS SIDE VIEW

41
47
58

42
48

43
49

59

44
55

64

45
56

65

46
57

66

50
60

51
61

52
62

53 54
63

AC

AK000280

CONNECTOR : C-40

PCM

AV

AK000280

CONNECTOR : C-40

PCM

AV