Mitsubishi 380. Manual — part 388

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-92

STEP 7. Measure the stoplamp switch output voltage to the
ENGINE-ECU at connector C-30 by backprobing.
(1) Remove the stoplamp switch from the mounting bracket.
(2) Do not disconnect connector C-30.

(3) Measure the voltage between terminal 1 and ground by

backprobing.

• When the switch button is out (closed circuit), voltage

should equal battery positive voltage.

• When the switch button is depressed (open circuit), volt-

age should measure less than 1.0 volt.

Q: Is the measured voltage battery positive voltage with

the switch button released (closed circuit), and less
than 1.0 volt with the switch button depressed (open
circuit)?
YES : Go to Step 9.
NO : Go to Step 8.

STEP 8. Check the stoplamp switch.
Refer to GROUP 35A, On-vehicle Service

− Stoplamp Switch

Check

P.35A-25

.

Q: Does the stoplamp switch pass the checks?

YES : Go to Step 9.
NO : Replace the stoplamp switch. Refer to GROUP 35A,

Brake Pedal

P.35A-24

.

10DB091A

CONNECTOR: C-30

2

1

3

4

3

2

1

4

AC201041

C-30 HARNESS
CONNECTOR:
HARNESS SIDE

AH

ACX02208

BRAKE PEDAL

STOPLIGHT
SWITCH

AD

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-93

STEP 9. Measure the stoplamp switch output voltage at the
ENGINE-ECU connector B-21 by using check harness
special tool MB992044.
(1) Install the stoplamp switch into the mounting bracket if it

was removed.

(2) Disconnect all the connectors from the ENGINE-ECU.
(3) Connect special tool MB992044 (check harness) between

the ENGINE-ECU and the body-side harness connector.

(4) Measure the voltage between connector B-21 (terminal 18)

and ground.

• When the brake pedal is depressed, voltage should

measure battery positive voltage.

• When the brake pedal is not depressed, voltage should

measure less than 1.0 volt.

Q: Is the measured voltage battery positive voltage with

the brake pedal depressed (closed circuit), and less
than 1.0 volt with the brake pedal released (open
circuit)?
YES : Go to Step 12.
NO : Go to Step 10.

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

10DB092A

B-21 HARNESS

CONNECTOR:

COMPONENT SIDE

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-94

STEP10. Check ENGINE-ECU connector B-21 and
stoplamp 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 11.
NO : Repair or replace the damaged components. Refer to

GROUP 00E, Harness Connector Inspection

P.00E-2

.

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

10DB091A

CONNECTOR: C-30

2

1

3

4

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-95

STEP 11. Check the harness for damage between
ENGINE-ECU connector B-21 terminal 18 and stoplamp
switch connector C-30 terminal 1.
Q: Is the harness wire in good condition?

YES : Go to Step 12.
NO : Repair or replace the harness wire.

16DB400A

COVER

ENGINE

CONTROL

UNIT

AIR

CLEANER

10DB091A

CONNECTOR: C-30

2

1

3

4