Mitsubishi Grandis. Manual — part 852

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-75

OPERATION

• Solenoid valve closes or opens according to the

signals from the engine-A/T-ECU.

• The engine-A/T-ECU energises or deenergises

solenoid valve, based on input signals such as
throttle position sensor opening angle, inhibitor
switch, etc.

DIAGNOSIS CODE SET CONDITIONS

If the drive terminal voltage of the torque converter
control clutch solenoid valve is 3.0 V or less, it is
judged that there is a short circuit or open circuit in
the torque converter control clutch solenoid valve,
and diagnosis code 36 is set.
If diagnosis code 36 is set 4 times, the transmission
is fixed in 3rd as a fail-safe measure.

POSSIBLE CAUSES

• Malfunction of damper clutch solenoid valve

• Damaged harness wires and connectors

• Malfunction of the engine-A/T-ECU

DIAGNOSIS

STEP 1. MUT-III diagnosis code

Q: Is diagnosis code 31 set?

YES :

Go to Step 9.

NO :

Go to Step 2.

STEP 2. MUT-III actuator test

Item 06: Damper clutch solenoid valve

OK: Operating sound can be heard.

Q: Is the check result normal?

YES :

Intermittent malfunction (Refer to GROUP

00

− How to Cope with Intermittent

Malfunction

P.00-5

).

NO :

Go to Step 3.

STEP 3. Connector check: B-109 A/T control
solenoid valve assembly connector

Check for the contact with terminals.

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Repair the defective connector.

STEP 4. Measure the resistance at A/T control
solenoid valve assembly connector B-109.

Disconnect the connector, and measure the
resistance between terminal No.7 and No.10 at the
solenoid valve side.

OK: 2.7

− 3.4 Ω (A/T fluid temperature 20°C)

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Check the damper clutch solenoid valve and
solenoid valve harness.

STEP 5. Measure the voltage at engine-A/T-ECU
connector C-114.
(1) Connect A/T control solenoid valve assembly

connector B-109.

AC303628

B-109 (GR)

Harness side

AG

Connector: B-109

AC303628AF

B-109 (GR)

Connector: B-109

Sensor side

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-76

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

(3) Measure the voltage between engine-A/T-ECU

connector C-114 terminal No.130 and earth.

OK: 6

−9 V

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Go to Step 6.

STEP 6. Connector check: C-114 engine-A/T-ECU
connector

Check for the contact with terminals.

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Repair the defective connector.

AC311284 AI

Connector: C-114 <LHD>

Connector: C-114 <RHD>

Engine-A/T-ECU

C-114 (GR)

C-114 (GR)

Engine-A/T-ECU

Harness side

124 123

130

131

132

133
141 140 139 138
146 145

129
137

128
136

127126

135
143

121
125
134
142

144

122

AC311284 AI

Connector: C-114 <LHD>

Connector: C-114 <RHD>

Engine-A/T-ECU

C-114 (GR)

C-114 (GR)

Engine-A/T-ECU

Harness side

124 123

130

131

132

133
141 140 139 138
146 145

129
137

128
136

127126

135
143

121
125
134
142

144

122

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-77

STEP 7. Check the harness between A/T control
solenoid valve assembly connector B-109
terminal No.7 and engine-A/T-ECU connector
C-114 terminal No.130.

Check the output line for short or open circuit.

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Repair the wiring harness.

STEP 8. MUT-III actuator test

Item 06: Damper clutch solenoid valve

OK: Operating sound can be heard.

Q: Is the check result normal?

YES :

Intermittent malfunction (Refer to GROUP

00

− How to Cope with Intermittent

Malfunction

P.00-5

).

NO :

Replace the engine-A/T-ECU.

STEP 9. Connector check: B-109 A/T control
solenoid valve assembly connector

Check for the contact with terminals.

Q: Is the check result normal?

YES :

Go to Step 10.

NO :

Repair the defective connector.

STEP 10. Measure the resistance at A/T control
solenoid valve assembly connector B-109.

Disconnect the connector, and measure the
resistance between terminal No.7 and No.10 at the
solenoid valve side.

OK: 2.7

− 3.4 Ω (A/T fluid temperature 20°C)

Q: Is the check result normal?

YES :

Go to Step 11.

NO :

Check the solenoid valve harness.

AC303628

B-109 (GR)

Harness side

AG

Connector: B-109

AC311284 AI

Connector: C-114 <LHD>

Connector: C-114 <RHD>

Engine-A/T-ECU

C-114 (GR)

C-114 (GR)

Engine-A/T-ECU

Harness side

124 123

130

131

132

133
141 140 139 138
146 145

129
137

128
136

127126

135
143

121
125
134
142

144

122

AC303628

B-109 (GR)

Harness side

AG

Connector: B-109

AC303628AF

B-109 (GR)

Connector: B-109

Sensor side

TROUBLESHOOTING <A/T>

AUTOMATIC TRANSMISSION (FF)

23A-78

STEP 11. Connector check: B-14X A/T control
relay connector

Check for the contact with terminals.

Q: Is the check result normal?

YES :

Go to Step 12.

NO :

Repair the defective connector.

STEP 12. Check the harness between A/T control
solenoid valve assembly connector B-109
terminal No.10 and A/T control relay connector
B-14X terminal No.1.

Check the power supply line for short or open circuit.

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Repair the wiring harness.

Code No.41 (1st), 42 (2nd), 43 (3rd), 44 (4th), 46 (reverse): Gear incorrect ratio

OPERATION

The engine-A/T-ECU detects the current gear/speed
according to the output signals from the input and
output shaft speed sensor.

DIAGNOSIS CODE SET CONDITIONS

If the output from the output shaft speed sensor
multiplied by the gear ratio is not the same as the
output from the input shaft speed sensor after
completing of shifting, the corresponding diagnosis
code is set.
If each diagnosis code is set 4 times, the
transmission is fixed in 3rd as a fail-safe measure.

POSSIBLE CAUSES

• Malfunction of input shaft speed sensor

• Malfunction of output shaft speed sensor

• Damaged harness wires and connectors

• Malfunction of the engine-A/T-ECU

• Malfunction of solenoid valve

• Malfunction of underdrive clutch retainer

• Malfunction of valve body

• Malfunction of transfer drive gear or driven gear

• Malfunction of low-reverse brake system (for

diagnosis codes 41, 46)

• Malfunction of underdrive clutch system (for

diagnosis codes 41, 42, 43)

• Malfunction of second brake system (for

diagnosis codes 42, 44)

• Malfunction of overdrive clutch system (for

diagnosis codes 43, 44)

• Malfunction of reverse clutch system (for

diagnosis code 46)

• Malfunction of one-way clutch system (for

diagnosis code 41)

AC311979AC

B-14X

Connector: B-14X

Front of
vehicle

Relay box
side

AC303628

B-109 (GR)

Harness side

AG

Connector: B-109

AC311979AC

B-14X

Connector: B-14X

Front of
vehicle

Relay box
side