Mitsubishi 380. Manual — part 383

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-72

(P0720): Output Shaft Speed Sensor System

.

10DB083A

A-13 (GR)

CONNECTOR: A-13

1

4

7

8

2 3

5

13 14

17

15

12

16

11

10

9

6

16DB564A

COVER

AIR

CLEANER

A/T

CONTROL

UNIT

CONNECTORS: B-19, B-22

AC305353AC

CONNECTOR: B-107

BATTERY

B-107 (GR)

3

2

1

10DB084A

CONNECTORS: C-214, 215

1
3 4

2
6

5

C-214

C-215

6

1
7

2

9

8

10

3

5

12

11

4

1314

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-73

CIRCUIT OPERATION

• The output shaft speed sensor generates a 0 ⇔ 5

volt pulse signal when the output shaft rotates.
The pulse signal frequency increases with a rise
output shaft speed.

• The output shaft speed sensor is connected to

the A/T-ECU connector B-22 (terminals 11 and
12) via the output shaft speed sensor connector
(terminals 1 and 2).

• The A/T-ECU detects the output shaft speed by

the signal input to terminal 11.

• The output shaft speed sensor generates the

pulse signal as the teeth of the transfer drive gear
pass the magnetic tip of the sensor.

.

DTC SET CONDITIONS

Check Conditions

• A/T range switch position: D, 5, 4, 3, 2, 1.

• Input speed: 1,000 r/min or more.

• Engine speed: 1,000 r/min or more.

• Transmission fluid temperature sensor voltage:

4.5 volts or less.

• Calculated slip (engine speed - input speed): 100

r/min or more.

Judgement Criteria

• Output speed: no signal change. (4 seconds)

• If (P0720) is set consecutively four times, the

transmission is locked into 3rd gear as a fail-safe
measure, and the "N" range light flashes once
per second.

Check Conditions

• A/T range switch position: D, 5, 4, 3, 2, 1.

• Input speed: 500 r/min or more.

• Transmission fluid temperature sensor voltage:

4.5 volts or less.

• Rapid output speed change: -31.9 r/min / 0.016

second or less.

Judgement Criteria

• Output speed: [(input speed - 200 r/min) / gear

ratio] or less. (4 seconds)

• If (P0720) is set consecutively four times, the

transmission is locked into 3rd gear as a fail-safe
measure, and the "N" range light flashes once
per second.

.

OBD-II DRIVE CYCLE PATTERN

Start the engine, and drive for 5 seconds, with 1st
gear fixed (1st gear in sport mode), at 20 km/h or
more with 50% or more of throttle valve opening.
Then stop the vehicle, and drive again for 5 seconds,
with 1st gear fixed (1st gear in sport mode), at 20
km/h or more with 50% or more of throttle valve
opening.

.

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

• Malfunction of the output shaft speed sensor

• Malfunction of the transfer drive gear or driven

gear

• 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

• MB992045: A/T-ECU Check Harness

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-74

STEP 1. Using diagnostic tool MB991958, check data list
item 6: Output Shaft Speed 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 6: Output Shaft Speed Sensor.

• When driving at a constant speed of 50km/h, the dis-

play should be "1,900

− 2,100 r/min" (Gear range:

3rd gear).

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

Q: Is the sensor within the specified range?

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.

STEP 2. Measure the power supply voltage at the output
shaft speed sensor connector B-107.
(1) Disconnect connector B-107 and measure at the harness

side.

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

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

• The voltage should measure battery positive voltage.

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

Q: Is the measured voltage battery positive voltage?

YES : Go to Step 5.
NO : Go to Step 3.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305353AC

CONNECTOR: B-107

BATTERY

B-107 (GR)

3

2

1

3 2 1

AC210661

B-107 HARNESS
CONNECTOR:
COMPONENT SIDE

AB

AUTOMATIC TRANSMISSION DIAGNOSIS

AUTOMATIC TRANSMISSION

23A-75

STEP 3. Check intermediate connector A-13 and junction
block connector C-214 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 4.
NO : Repair or replace the damaged components. Refer to

GROUP 00E, Harness Connector Inspection

P.00E-2

.

STEP 4. Check the harness for open circuit or short circuit
to ground between the output shaft speed sensor
connector B-107 terminal 3 and the junction block
connector C-214 terminal 12.
Q: Is the harness wire in good condition?

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

10DB085A

CONNECTOR: C-214

6

1
7

2

9

8

10

3

5

12

11

4

1314

10DB083A

A-13 (GR)

CONNECTOR: A-13

1

4

7

8

2 3

5

13 14

17

15

12

16

11

10

9

6

AC305353AC

CONNECTOR: B-107

BATTERY

B-107 (GR)

3

2

1

10DB085A

CONNECTOR: C-214

6

1
7

2

9

8

10

3

5

12

11

4

1314