Mitsubishi Galant (2004+). Manual - part 648

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-143

STEP 19. Measure the transmission range switch output 
voltage at PCM connector B-21 by using check harness 
special tool MB991923.

(1) Disconnect all the connectors from the PCM.

(2) Connect special tool MB991923 (check harness) between 

the PCM and the body-side harness connector.

(3) Turn the ignition switch to the "ON" position.
(4) Move the selector lever to the "N" position.

AC306248AC

B-21 
(B)

CONNECTOR: B-21

PCM

AIR
CLEANER

73

80

54

67

60

71 72

77 78 79

64

51

59

58

65

52

66

53

75

74

76

81 82

83

63

JAE

62

68

61

55

69

56

70

57

AC209793AG

SPECIAL TOOL 33-PIN CONNECTOR
(PCM CONNECTOR B-21)

B-21
(GR)

55

56

54 53 52 51

57

62 61 60 59 58

63

69 68 67 66 65 64

70

75 74 73 72 71

76

82 81 80 79 78 77

83

PCM

MB991923

BODY SIDE
HARNESS

AUTOMATIC TRANSAXLE DIAGNOSIS

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AUTOMATIC TRANSAXLE

23A-144

(5) Measure the voltage between terminal 77 and ground.

• The voltage should measure battery positive voltage.

(6) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?

YES : Go to Step 11.
NO :  Go to Step 20.

STEP 20. Check PCM connector B-21 for loose, corroded 
or damaged terminals, or terminals pushed back in the 
connector.

Q: Are the connector and terminals in good condition?

YES : Go to Step 21.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

.

AC210404

51

58

71

64

77

76

83

70

63

57

73 72

75 74

80

82 81

79 78

54

67

JAE

62

69

56

61

68

55

59

66

60

53

65

52

AC

B-21 HARNESS 
CONNECTOR:
COMPONENT SIDE

AC306248AC

B-21 
(B)

CONNECTOR: B-21

PCM

AIR
CLEANER

73

80

54

67

60

71 72

77 78 79

64

51

59

58

65

52

66

53

75

74

76

81 82

83

63

JAE

62

68

61

55

69

56

70

57

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-145

STEP 21. Check harness for open circuit or short circuit to 
ground between PCM connector B-21 terminal 77 and 
transmission range switch connector B-110 terminal 4.

Q: Is the harness wire in good condition?

YES : Go to Step 5.
NO :  Repair or replace the harness wire.

AC306248AC

B-21 
(B)

CONNECTOR: B-21

PCM

AIR
CLEANER

73

80

54

67

60

71 72

77 78 79

64

51

59

58

65

52

66

53

75

74

76

81 82

83

63

JAE

62

68

61

55

69

56

70

57

AC210068

CONNECTOR: B-110

B-110 (B)

AE

TRANSMISSION
RANGE SWITCH

1

7

2

8

3

5

9

4

10

6

AUTOMATIC TRANSAXLE DIAGNOSIS

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AUTOMATIC TRANSAXLE

23A-146

STEP 22. Check the transmission range switch.

Measure the resistance between the terminals for each trans-
mission range as indicated in the table below.

NOTE: For vehicles with sport mode, four positions (P, R, N, D) 
are used.
Q: Is the measured resistance less than 2 ohms for each 

transmission range?
YES : Go to Step 23.
NO :  Replace the transmission range switch. Refer to 

GROUP 23B, Transaxle 

P.23B-10

.

TRANS
MISSION 
RANGE

TERMINAL 
CONNECTION OF 
TESTER

SPECIFIED 
CONDITION

P

3 

− 8, 9 − 10

Less than 2 ohms.

R

7 

− 8

N

4 

− 8, 9 − 10

D

1 

− 8

3

5 

− 8

2

2 

− 8

L

6 

− 8

AC305881

AC305532

AC305679

<F4A4B>

<F4A5A>

AC

TRANSMISSION
RANGE SWITCH

TRANSMISSION
RANGE SWITCH

AC304078

P

R

N

D

<F4A4B>

AC

3

2

L

AC210182AC

P

R

N

D

<F4A5A>