Mitsubishi Galant 9G. Manual — part 492

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-46

.

CIRCUIT OPERATION

• The PCM (terminal 74) applies 5 volts to the

transmission fluid temperature sensor output ter-
minal (terminal 1).

• The transmission fluid temperature sensor circuit

is grounded to the PCM (terminal 69).

• When the transmission fluid temperature is cold,

the transmission fluid temperature sensor resis-
tance is high. When the transmission fluid tem-
perature is hot, the transmission fluid
temperature sensor resistance is low.

.

DESCRIPTIONS OF MONITOR METHODS

• If transmission fluid temperature is below speci-

fied value even after driving test for more than
specified period, PCM judges that transmission
fluid temperature sensor has a failure.

.

MONITOR EXECUTION

• Continuous

.

MONITOR EXECUTION CONDITIONS
(OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• DTC 23 (P0720): Output shaft speed sensor mal-

function

Sensor (The sensor below is determined to be

normal)

• Output shaft speed sensor

.

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

AC306322

CONNECTOR: B-108

B-108 (GR)

AC

TRANSMISSION
RANGE SWITCH

2

7

1

8

3

9

4

6

10

5

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-47

LOGIC FLOW CHARTS (Monitor Sequence)

.

DTC SET CONDITIONS

Check Conditions

• Engine speed: 1,000 r/min or more.

• Output speed: 1,000 r/min or more.

• Accumulated time in above condition: 10 min-

utes.

Judgement Criteria

• Transmission fluid temperature sensor voltage:

4.5 volts or more. (1 second)

.

OBD-II DRIVE CYCLE PATTERN

Start the engine, drive at 60 km/h (37 mph) or more
for 15 minutes in total.

Good

Malfunction

Timer start

N

E

:

Engine speed

N

OPG-B

: Output speed (output

shaft speed sensor)

Timer hold

Timer accumulate

START

N

E

> 1,000 r/min and

N

OPG-B

> 1,000 r/min

Continuous failure
for 1 sec.

Transmission fluid
temperature sensor
voltage > 4.5 V

Timer > 10 min.

END

N

E

> 1,000 r/min and

N

OPG-B

> 1,000 r/min

AC205204

Yes

No

Yes

No

Yes

No

Yes

No

Yes

No

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-48

.

TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CODE TO BE
SET ARE:)

• Malfunction of the transmission fluid temperature

sensor circuit

• Damaged harness or connector

• Malfunction of the PCM

DIAGNOSIS

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

STEP 1. Using scan tool MB991958, check data list item 15:
Transmission Fluid Temperature Sensor.

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.
(2) Start the engine.
(3) Set scan tool MB991958 to the data reading mode.

• Item 15: Transmission Fluid Temperature Sensor.

• When the engine is cool: Almost equal to the ambi-

ent temperature (atmospheric temperature)
NOTE: Set scan tool MB991958 to the data reading
mode for item number 13, Intake Air Temperature
(IAT) Sensor and note the temperature measure-
ment. When the engine is cool, the temperature
should be almost equal to the ambient temperature
(atmospheric temperature), and the IAT sensor mea-
surement should be approximately the same as the
Transmission Fluid Temperature Sensor.

• When the engine is warm: 70 − 80°C (158 − 176°F).

(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

− How to

Cope with Intermittent Malfunction

P.00-14

.

NO : Go to Step 2.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-49

STEP 2. Measure the sensor output voltage at the A/T
control solenoid valve assembly connector B-108 by
backprobing.
(1) Do not disconnect connector B-108.
(2) Turn the ignition switch to the "ON" position.

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

backprobing.

• When transmission fluid temperature is 20°C (68°F),

voltage should measure between 3.8 and 4.0 volts.

• When transmission fluid temperature is 40°C (104°F),

voltage should measure between 3.2 and 3.4 volts.

• When transmission fluid temperature is 80°C (176°F),

voltage should measure between 1.7 and 1.9 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage within the specified range?

YES : Go to Step 6.
NO : Go to Step 3.

STEP 3. Measure the ground voltage at the A/T control
solenoid valve assembly connector B-108 by backprobing.
(1) Do not disconnect connector B-108.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 2 and ground by

backprobing.

• The voltage should measure 0.5 volt or less.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage 0.5 volt or less?

YES : Go to Step 4.
NO : Go to Step 7.

AC306322

CONNECTOR: B-108

B-108 (GR)

AC

TRANSMISSION
RANGE SWITCH

2

7

1

8

3

9

4

6

10

5

5

2

1

7

3

8

4

9

6

10

AC200996

B-108 HARNESS
CONNECTOR:
HARNESS SIDE

AG

AC306322

CONNECTOR: B-108

B-108 (GR)

AC

TRANSMISSION
RANGE SWITCH

2

7

1

8

3

9

4

6

10

5

5

2

1

7

3

8

4

9

6

10

AC201005

B-108 HARNESS
CONNECTOR:
HARNESS SIDE

AG