Mitsubishi Galant (2004+). Manual - part 189

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

17-47

(4) Measure the terminal voltage between special tool 23-pin 

connector (without red tape) terminal 33 (PCM connector 

B-20 terminal 33) and ground.

• When the brake pedal is depressed, the voltage should 

measure battery positive voltage (approximately 12 
volts).

• When the brake pedal is released, the voltage should 

measure 1 volt or less.

(5) Turn the ignition switch to the "LOCK" (OFF) position.
(6) Disconnect special tool MB991923 between the PCM and 

the body-side harness connector.

(7) Reconnect all the connectors to the PCM.
Q: Is the measured voltage battery positive voltage 

(approximately 12 volts) when the brake pedal is 
depressed and 1 volt or less when the brake pedal is 
released?
YES : Go to Step 20 .
NO :  Go to Step 16 .

STEP 16. Check the stoplight switch.
(1) Remove the stoplight switch (Refer to GROUP 35A, Brake 

Pedal 

P.35A-24

).

(2) Connect an ohmmeter to the stoplight switch between 

terminals 3 and 4.

(3) Check for continuity between the terminals when the 

plunger of the stoplight switch is pushed in and when it is 
released.

(4) The stoplight switch is operating properly if the circuit is 

open between terminals 3 and 4 when the plunger is 
released, and if resistance value is less than 2 ohms 
between terminals 3 and 4 when the plunger is pushed in to 
a depth of within 4.5 mm (0.18 inch) from the outer case 
edge surface.

Q: Is the stoplight switch operating properly?

YES : Install the stoplight switch (Refer to GROUP 35A, 

Brake Pedal 

P.35A-24

). Then go to Step 17 .

NO :  Replace the stoplight switch (Refer to GROUP 35A, 

Brake Pedal 

P.35A-24

). Then go to Step 22 .

AC209671AB

SPECIAL TOOL 23-PIN
CONNECTOR
(WITHOUT RED TAPE):
COMPONENT SIDE

1

2

3

4

ACX01917AJ

C-30 STOPLIGHT SWITCH
CONNECTOR

AC205057    

CONTINUITY

NO
CONTINUITY

4.5 mm (0.18 in)

AC

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

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STEP 17. Check PCM connector B-20 and stoplight switch 
connector C-30 for loose, corroded or damaged terminals, 
or terminals pushed back in the connector.

Q: Are the connectors and terminals in good condition?

YES : Go to Step 18 .
NO :  Repair or replace the damaged components (Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

). Then go to Step 22 .

AC305710

B-20 HARNESS

CONNECTOR:

COMPONENT SIDE

AD

B-20

CONNECTOR: B-20

AIR CLEANER

PCM

AC305231AO

CONNECTOR: C-30

C-30

C-30 HARNESS
CONNECTOR:
COMPONENT SIDE

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

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STEP 18. Check the harness wire between PCM connector 
B-20 terminal 33 and stoplight switch connector C-30 
terminal 3 for damage.

Q: Is the harness wire in good condition?

YES : Go to Step 19 .
NO :  Repair the damaged harness wire. Then go to Step 

22 .

AC305710

B-20 HARNESS

CONNECTOR:

COMPONENT SIDE

AD

B-20

CONNECTOR: B-20

AIR CLEANER

PCM

AC305231AO

CONNECTOR: C-30

C-30

C-30 HARNESS
CONNECTOR:
COMPONENT SIDE

AUTO-CRUISE CONTROL

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ENGINE AND EMISSION CONTROL

17-50

STEP 19. Check the harness wire between stoplight switch 
connector C-30 terminal 4 and ground for damage.

Q: Is the harness wire in good condition?

YES : Go to Step 20 .
NO :  Repair the damaged harness wire. Then go to Step 

22 .

STEP 20. Using scan tool MB991958, check data list item 
06: Brake Switch.

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 

P.17-12

.

(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991958 to data reading mode.

• Auto-cruise control system item 06, Brake Switch.

• When the brake pedal is depressed, the display on 

scan tool MB991958 should be "ON".

• When the brake pedal is released, the display on 

scan tool MB991958 should be "OFF".

(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Disconnect scan tool MB991958.
Q: Is the switch operating properly?

YES : Go to Step 21 .
NO :  Replace the PCM [Refer to GROUP 13A, Power 

Control Module (PCM) 

P.13A-1121

]. Then go to Step 

22 .

AC305231AO

CONNECTOR: C-30

C-30

C-30 HARNESS
CONNECTOR:
COMPONENT SIDE

AC305032

PCM

GROUND
TERMINAL

AC

RELAY BOX

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827