Mitsubishi Galant (2004+). Manual - part 135

ON-VEHICLE SERVICE

TSB Revision

ENGINE MECHANICAL <2.4L ENGINE>

11A-13

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.
2. Connect scan tool MB991958 to the data link connector.
3. Set up a timing light.
4. Start the engine and run it at idle.
5. Check that the idle speed is approximately 700 r/min.
6. Select scan tool MB991958 actuator test "item number 17".
7. Check that basic ignition timing is within the standard value.

Standard value: 5

° BTDC ± 3°

8. If the basic ignition timing is not within the standard value, 

check the following items:

• Diagnostic output

• Timing belt cover and crankshaft position sensor installation 

conditions

• Crankshaft sensing blade condition

CAUTION

If the actuator test is not canceled, the forced drive will 
continue for 27 minutes. Driving in this state could lead to 
engine failure.
9. Press the clear key on scan tool MB991958 (select forced 

drive stop mode), and cancel the actuator test.

10.Check that the actual ignition timing is at the standard value.

Standard value: Approximately 10

° BTDC

NOTE: Ignition timing fluctuates about 

±

 7

°

 Before Top Dead 

Center, even under normal operating condition.
NOTE: It is automatically further advanced by about 5

°

 to 

10

°

 Before Top Dead Center at higher altitudes.

CURB IDLE SPEED CHECK

M1111003500568

Required Special Tool:
MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

1. Before checks, set the vehicle in the following condition.

• Engine coolant temperature: 80 − 95°C (176 − 203°F)

• Lights and all accessories: OFF

• Transaxle: P range

NOTE: Vehicles for Canada, the headlight, taillight, etc. 
remain lit even when the lighting switch is in "OFF" position 
but this is no problem for checks.

AC302077
AC305412

AC306958AB

MB991824

MB991910

MB991668

DATA LINK

CONNECTOR

ON-VEHICLE SERVICE

TSB Revision

ENGINE MECHANICAL <2.4L ENGINE>

11A-14

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.
2. Connect scan tool MB991958 to the data link connector.
3. Check the basic ignition timing.

Standard value: 5

° BTDC ± 3°

4. Start the engine.
5. Run the engine at idle for 2 minutes.
6. Check the idle speed. Select item number 22 and take a 

reading of the idle speed.

Curb idle speed: 700 

± 100 r/min

NOTE: The idle speed is controlled automatically by the idle 
air control system.

7. If the idle speed is outside the standard value, refer to 

GROUP 13A, Multiport Fuel Injection (MFI) <2.4L Engine> 

− 

Multiport Fuel Injection (MFI) Diagnosis 

− Symptom Chart 

P.13A-38

.

IDLE MIXTURE CHECK

M1111002100318

Required Special Tool:
MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

1. Before checks, set the vehicle in the following condition:

• Engine coolant temperature: 80 − 95°C (176 − 203°F)

• Lights and all accessories: OFF

• Transaxle: P range

NOTE: Vehicles for Canada, the headlight, taillight, etc. 
remain lit even when the lighting switch is in "OFF" position 
but this is no problem for checks.

AC302077
AC305412

AC306958AB

MB991824

MB991910

MB991668

DATA LINK

CONNECTOR

ON-VEHICLE SERVICE

TSB Revision

ENGINE MECHANICAL <2.4L ENGINE>

11A-15

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.
2. Connect scan tool MB991958 to the data link connector.
3. Check that the basic ignition timing is within the standard 

value. 

Standard value: 5

° BTDC ± 3°

4. Start the engine and increase the engine speed to 2,500 

r/min for 2 minutes.

5. Set the CO, HC tester.
6. Check the CO contents and the HC contents at idle.

Standard value:

CO contents: 0.5 % or less
HC contents: 100 ppm or less

7. If the CO and HC contents do not remain inside the standard 

value, check the following items:
NOTE: Replace the catalytic converter when the CO and HC 
contents do not remain inside the standard value, even 
though the result of the inspection is normal for all items.

• Diagnostic output

• Closed-loop control (When the closed-loop control is carried 

out normally, the output signal of the heated oxygen sensor 
changes between 0 

− 400 mV and 600 − 1,000 mV at idle.)

• Fuel pressures

• Injector

• Ignition coil, spark plug

• EGR system

• Evaporative emission system

• Compression pressure

AC302077
AC305412

AC306958AB

MB991824

MB991910

MB991668

DATA LINK

CONNECTOR

ON-VEHICLE SERVICE

TSB Revision

ENGINE MECHANICAL <2.4L ENGINE>

11A-16

COMPRESSION PRESSURE CHECK

M1111002600603

1. Before checks, check that the engine oil, starter and battery 

are normal. Also, set the vehicle in the following condition:

• Engine coolant temperature: 80 − 95°C (176 − 203°F)

• Lights and all accessories: OFF

• Transaxle: P range

NOTE: Vehicles for Canada, the headlight, taillight, etc. 
remain lit even when the lighting switch is in "OFF" position 
but this is no problem for checks.

2. Remove all of the ignition coils.
3. Disconnect the crankshaft position sensor connector.

NOTE: Doing this will prevent the engine control module 
from carrying out ignition and fuel injection.

WARNING

Keep your distance from the spark plug hole when 
cranking. Oil, fuel, etc., may spray out from the spark 
plug hole and may cause serious injury.

4. Cover the spark plug hole with a shop towel etc., during 

cranking. After the engine has been cranked, check for 
foreign material adhering to the shop towel.

5. Set a compression gauge to one of the spark plug holes.
6. Crank the engine with the throttle valve fully open and 

measure the compression pressure.

Standard value (at engine speed of 200 r/min): 
1,560 kPa (226 psi)
Minimum limit (at engine speed of 200 r/min): 
1,130 kPa (164 psi)

7. Measure the compression pressure for all the cylinders, and 

check that the pressure differences of the cylinders are 
below the limit.

Limit: 98 kPa (14 psi)

8. If there is a cylinder with compression or a compression 

difference that is outside the limit, pour a small amount of 
engine oil through the spark plug hole, and repeat the 
operations in steps 6 to 8.

(1) If the compression increases after oil is added, the cause 

of the malfunction is a worn or damaged piston ring 
and/or cylinder inner surface.

(2) If the compression does not rise after oil is added, the 

cause is a burnt or defective valve seat, or pressure is 
leaking from the gasket.

9. Connect the crankshaft position sensor connector.
10.Install the ignition coils.
11.Use the scan tool to erase the diagnostic trouble codes.

NOTE: This will erase the diagnostic trouble code resulting 
from the crankshaft position sensor connector being discon-
nected.

AK303009

CRANKSHAFT
POSITION SENSOR
CONNECTOR

AB

GENERATOR

AK204360

COMPRESSION GAUGE

AC