Mitsubishi Grandis. Manual — part 864

TROUBLESHOOTING <A/T KEY INTERLOCK AND SHIFT LOCK MECHANISMS>

AUTOMATIC TRANSMISSION (FF)

23A-123

OSCILLOSCOPE INSPECTION
PROCEDURE

M1231008500379

WAVEFORM SAMPLE

TROUBLESHOOTING <A/T KEY INTERLOCK AND SHIFT

LOCK MECHANISMS>

TROUBLE SYMPTOM CHART

M1232001800510

Terminal
No.

Check item

Inspection conditions

Normal
condition
(Waveform
sample)

70

Crank angle sensor

Selector lever position: P Engine: Idling (vehicle

stopped)

Waveform A

79

Vehicle speed signal

Selector lever position:
Sport mode (3rd gear)

Driving at constant
speed of 50 km/h in 3rd
gear ( 1,400

− 1,700

r/min)

64

Input shaft speed sensor

Waveform B

73

Output shaft speed
sensor

128

LR solenoid valve

• Ignition switch: ON

• Selector lever

position: P

• Engine: Stopped

• Throttle (Accelerator)

opening voltage: 1 V
or less

Force drive each
solenoid valve (Actuator
test)

Waveform C

137

UD solenoid valve

136

2ND solenoid valve

138

OD solenoid valve

130

DCC solenoid valve

AC001872AC

(V)

Waveform A

(ms)

0

5

AC001874AE

(V)

Waveform C

0

5

AC001875

(V)

Waveform D

0

20

40

60

AG

Symptom

Inspection
procedure
number

Reference
page

When the ignition key is at a position other than the LOCK (OFF) position,
the selector lever can be moved from the P to the R position even though
the brake pedal is not depressed.

1

P.23A-124

When the ignition key is at a position other than the LOCK (OFF) position,
the selector lever cannot be moved from the P to the R position even
though the brake pedal is being depressed.

2

P.23A-124

The ignition key is at the LOCK (OFF) position, but the selector lever can
be moved from the P to the R position when the brake pedal is
depressed.

3

P.23A-124

TROUBLESHOOTING <A/T KEY INTERLOCK AND SHIFT LOCK MECHANISMS>

AUTOMATIC TRANSMISSION (FF)

23A-124

SYMPTOM PROCEDURES

INSPECTION PROCEDURE 1: When the ignition key is at a position other than the LOCK (OFF)
position, the selector lever can be moved from the P to the R position even though the brake pedal is
not depressed.

COMMENTS ON TROUBLE SYMPTOM

The cause is probably a malfunction of the selector
lever assembly lock cam or shift lock cable.

POSSIBLE CAUSES

• Malfunction of lock cam

• Malfunction of shift lock cable

DIAGNOSIS

Check by referring to the possible causes.

INSPECTION PROCEDURE 2: When the ignition key is at a position other than the LOCK (OFF)
position, the selector lever cannot be moved from the P to the R position even though the brake pedal
is being depressed.

COMMENTS ON TROUBLE SYMPTOM

The cause is probably a malfunction of the selector
lever assembly, transmission control cable, shift lock
cable, key interlock cable or engine starting switch
assembly.

POSSIBLE CAUSES

• Malfunction of selector lever assembly

• Malfunction of transmission control cable

• Malfunction of shift lock cable

• Malfunction of key interlock cable

• Malfunction of engine starting switch assembly

DIAGNOSIS

Check by referring to the possible causes.

INSPECTION PROCEDURE 3: The ignition key is at the LOCK (OFF) position, but the selector lever
can be moved from the P to the R position when the brake pedal is depressed.

COMMENTS ON TROUBLE SYMPTOM

The cause is probably a malfunction of the key
interlock cable, selector lever assembly or engine
starting switch assembly.

POSSIBLE CAUSES

• Malfunction of key interlock cable

• Malfunction of selector lever assembly

• Malfunction of engine starting switch assembly

DIAGNOSIS

Check by referring to the possible causes.

The selector lever cannot be easily moved from the P to the R position.

4

P.23A-125

The selector lever cannot be moved from the R to the P position.

5

P.23A-125

The ignition key cannot be turned to the LOCK (OFF) position when the
selector lever is at the P position.

6

P.23A-125

The ignition key can be turned to the LOCK (OFF) position when the
selector lever is at a position other than the P position.

7

P.23A-125

Symptom

Inspection
procedure
number

Reference
page

TROUBLESHOOTING <A/T KEY INTERLOCK AND SHIFT LOCK MECHANISMS>

AUTOMATIC TRANSMISSION (FF)

23A-125

INSPECTION PROCEDURE 4: The selector lever cannot be easily moved from the P to the R position.

COMMENTS ON TROUBLE SYMPTOM

The cause is probably a malfunction of the selector
lever assembly, transmission control cable, shift lock
cable, key interlock cable or engine starting switch
assembly.

POSSIBLE CAUSES

• Malfunction of selector lever assembly

• Malfunction of transmission control cable

• Malfunction of shift lock cable

• Malfunction of key interlock cable

• Malfunction of engine starting switch assembly

DIAGNOSIS

Check by referring to the possible causes.

INSPECTION PROCEDURE 5: The selector lever cannot be moved from the R to the P position.

COMMENTS ON TROUBLE SYMPTOM

The cause is probably a malfunction of the selector
lever assembly or transmission control cable.

POSSIBLE CAUSES

• Malfunction of selector lever assembly

• Malfunction of transmission control cable

DIAGNOSIS

Check by referring to the possible causes.

INSPECTION PROCEDURE 6: The ignition key cannot be turned to the LOCK (OFF) position when the
selector lever is at the P position.

COMMENTS ON TROUBLE SYMPTOM

The cause is probably a malfunction of the selector
lever assembly, key interlock cable or engine starting
switch assembly.

POSSIBLE CAUSES

• Malfunction of selector lever assembly

• Malfunction of key interlock cable

• Malfunction of engine starting switch assembly

DIAGNOSIS

Check by referring to the possible causes.

INSPECTION PROCEDURE 7: The ignition key can be turned to the LOCK (OFF) position when the
selector lever is at a position other than the P position.

COMMENTS ON TROUBLE SYMPTOM

The cause is probably a malfunction of the key
interlock cable or engine starting switch assembly.

POSSIBLE CAUSES

• Malfunction of key interlock cable

• Malfunction of engine starting switch assembly

DIAGNOSIS

Check by referring to the possible causes.

ON-VEHICLE SERVICE

AUTOMATIC TRANSMISSION (FF)

23A-126

ON-VEHICLE SERVICE

ESSENTIAL SERVICE

AUTOMATIC TRANSMISSION FLUID
(ATF) CHECK

M1231000900362

CAUTION

When replacing the transmission with a new one,
overhauling the existing transmission, or driving
in a harsh condition, the A/T fluid cooler line
should always be flushed out and A/T fluid
should be replaced with a new one.
1. Drive the vehicle until the A/T fluid temperature

reaches the normal temperature (70

− 80°C)

NOTE: Measure A/T fluid temperature using
MUT-III.
NOTE:

Check the oil level referring to the characteristics
chart shown at left if it takes some time to reach
the normal operation temperature of A/T fluid (70

−

80

°

C).

2. Park the vehicle on a level surface.
3. Move the selector lever to all positions to fully

charge the torque converter and the fluid lines
with A/T fluid, and then move the selector lever to
the N position.

4. After wiping away any dirt from around the oil

level gauge, pull out the oil level gauge and check
the level of A/T fluid.
NOTE: If the A/T fluid has a burnt smell, or if it has
become very contaminated or dirty, it means that
the A/T fluid has become contaminated by minute
particles form bushings (metal) or worn parts. In
such a case, the transmission needs to be
overhauled and the A/T fluid cooler line needs to
be flushed out.

5. Check that the A/T fluid level is between the HOT

marks on the oil level gauge. If the A/T fluid level
is too low, add more A/T fluid until the level
reaches between the HOT marks.

Automatic transmission fluid: DIA QUEEN
ATF SP III

NOTE: If the A/T fluid level is too low, the oil pump
draws air into the system along with the A/T fluid,
and air bubbles will thus from in the fluid circuit.
This will cause a drop in fluid pressure and cause
the shift points to change and the clutches and
brakes to slip. If the A/T fluid level is too high, the
gear will churn the A/T fluid and cause bubbles to
develop, which can then cause the same
problems as when the A/T fluid is too low. In either
case, the air bubbles can cause overheating and
oxidation of the A/T fluid, and also prevent the
valves, clutches and brakes from operating
normally. In addition, if bubbles develop in the A/T
fluid, the A/T fluid can overflow from the
transmission vent holes and be mistaken for
leaks.

6. Securely re-insert the oil level gauge.

AUTOMATIC TRANSMISSION FLUID
(ATF) REPLACEMENT

M1231001000351

CAUTION

Before replacing the transmission with a new
one, overhauling the existing transmission, or
connecting the cooler pipe to the transmission,
the A/T fluid cooler line should always be flushed
out.
In you have an A/T fluid changer, use the A/T fluid
changer to flush the A/T fluid. If you do not have an
A/T fluid changer, follow the procedure given below.

HO

T

AC312577

Fluid level [mm]

Fluid temperature [ ]

10

0

-10

-20

-30

40

60

80

Fluid level

AB

AC303532AC