Mitsubishi 380. Manual - part 374

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-36

DIAGNOSTIC TROUBLE CODE PROCEDURES

 (P0713): Transmission Fluid Temperature Sensor System (Open Circuit)

.

CIRCUIT OPERATION

• The A/T-ECU connector B-22 (terminal 6) applies 

5 volts to the transmission fluid temperature sen-
sor output terminal (terminal 1).

•  The transmission fluid temperature sensor circuit 

is grounded to the A/T-ECU connector B-22 (ter-
minal 12).

• 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.

.

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 or more for 15 min-
utes in total.

.

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 A/T-ECU

Circuit drawings

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

• Refer to component locations GROUP-

70

DIAGNOSIS

Required Special Tool:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

16DB564A

COVER

AIR

CLEANER

A/T

CONTROL

UNIT

CONNECTORS:  B-19, B-22

AC306322

CONNECTOR: B-108

B-108 (GR)

AC

TRANSMISSION
RANGE SWITCH

2

7

1

8

3

9

4

6

10

5

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-37

STEP 1. Using diagnostic tool MB991958, check data list 
item 7: Transmission Fluid Temperature Sensor.

CAUTION

To prevent damage to diagnostic tool MB991958, always 
turn the ignition switch to the "LOCK" (OFF) position 
before connecting or disconnecting diagnostic tool 
MB991958.
(1) Connect diagnostic tool MB991958 to the data link 

connector.

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

• Item 7: Transmission Fluid Temperature Sensor.

• When the engine is cool: Diagnostic tool display is 

almost equal to the ambient temperature (atmo-
spheric temperature)

NOTE: Set diagnostic tool MB991958 to the Engine 
MPI data list reading mode for item number 5, Intake 
Air Temperature (IAT) Sensor and note the tempera-
ture measurement. When the engine is cool, the 
temperature should be almost equal to the ambient 
temperature (atmospheric temperature), and the IAT 
sensor measurement should be approximately the 
same as the Transmission Fluid Temperature Sen-
sor.

• When the engine is warm, at approximately running 

temperature: 70 

− 80°C.

(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.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-38

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, voltage 

should measure between 3.8 and 4.0 volts.

• When transmission fluid temperature is 40°C, voltage 

should measure between 3.2 and 3.4 volts.

• When transmission fluid temperature is 80°C, 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

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-39

STEP 4. Check the sensor output voltage at A/T control 
solenoid valve assembly connector B-108.
(1) Disconnect connector B-108 and measure at the harness 

side.

(2) Turn the ignition switch to the "ON" position.

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

• The voltage should measure between 4.5 and 4.9 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the measured voltage between 4.5 and 4.9 volts?

YES : Go to Step 5.
NO :  Go to Step 9.

AC306322

CONNECTOR: B-108

B-108 (GR)

AC

TRANSMISSION
RANGE SWITCH

2

7

1

8

3

9

4

6

10

5

2

5

6

10

4

9

3

8

1

7

AC201006AE

B-108 HARNESS
CONNECTOR: 
COMPONENT SIDE