AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-25
TORQUE CONVERTER STALL TESTM1231005400362
This test measures the maximum engine speed when the
selector lever is in the "D" or "R" position and the torque con-
verter stalls. This tests the operation of the torque converter,
starter motor and one-way clutch operation, as well as the hold-
ing performance of the clutches and brakes in the transmission.
Do not let anyone stand in front of or behind the vehi-
cle while this test is performed.
1. Check the transmission fluid level and temperature. Check
the engine coolant temperature.
Transmission fluid level: At the "HOT" mark on the dipstick
Transmission fluid temperature: 70 80C
Engine coolant temperature: 80 100C
NOTE: Measures transmission fluid temperature with
diagnostic tool MB991958 (MUT-III sub assembly).
2. Check both rear wheels.
3. Pull the parking brake lever on, with the brake pedal fully
depressed.
4. Start the engine. 9 Transmission
range: N (on a
flat and straight
road)Monitor data list
No.22 and No.23
with the diagnostic
tool MB991958
(MUT-III sub
assembly)
(1) Move selector
lever to R range,
drive at constant
speed of 10 km/hThe ratio between
data list No.22 and
No.23 should be the
same as the gear
ratio when reversing.Does not
shiftInput shaft
speed sensor
system
(P.23A-55).
Output shaft
speed sensor
system
(P.23A-72).
Reverse gear
incorrect ratio
(P.23A-196).
STEP CONDITION
BEFORE
TEST/OPERATIONTEST/OPERATION STANDARD INSPECTION
ITEMINSPECTION
PROCEDURE
PA G E
AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-26
The throttle should not be fully open for any more than
five seconds.
If you repeat the stall test when the transmission fluid
temperature is greater than 80
C, move the selector
lever to the "N" position and let the engine run at
approximately 1,000 r/min for at least one minute. Wait
until the transmission fluid temperature returns to 80
C
or less.
5. Move the selector lever to the "D" position. Fully depress the
accelerator pedal and read the maximum engine speed at
this time.
Standard value: Stall speed: 2,100
2,600 r/min
6. Move the selector lever to the "R" position. Fully depress the
accelerator pedal and read the maximum engine speed.
Standard value: Stall speed: 2,100
2,600 r/min
TORQUE CONVERTER STALL TEST JUDGMENT
RESULTS
1. Stall speed is too high in both "D" and "R" range
Malfunction of the torque converter (Slippage on the splines
of the torque converter and the input shaft)
Low line pressure
Low-reverse brake slippage and malfunction of the one-way
clutch
2. Stall speed is too high in "D" range only
Underdrive clutch slippage
3. Stall speed is too high in "R" range only
Reverse clutch slippage
4. Stall speed is too low in both "D" and "R" ranges
Malfunction of the torque converter (Slippage of the
one-way clutch)
Insufficient engine output
HYDRAULIC PRESSURE TESTSM1231005500392
The transmission fluid temperature should be between 70
80C during the test.
1. Check the transmission fluid level and temperature. Check
engine coolant temperature.
Transmission fluid level: "HOT" mark on the dipstick
Transmission fluid temperature: 70 80C
Engine coolant temperature: 80 100C
2. Raise the vehicle so that the wheels are free to turn.
AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-27
3. Connect the special tools (3.0 MPa (427 psi) oil pressure
gauge [MD998330] and adapters [MD998332, MD998900])
to each pressure discharge port.
NOTE: .
2ND: Second brake pressure port
UD: Underdrive clutch pressure port
LR: Low-reverse brake pressure port
DR: Torque converter release pressure port
DA: Torque converter apply pressure port
RV: Reverse clutch pressure port
OD: Overdrive clutch pressure port
DIR: Direct clutch pressure port
RED: Reduction clutch pressure port
4. Restart the engine.
5. Check that there are no leaks around the special tool port
adapters.
6. Measure the hydraulic pressure at each port under the
conditions given in the standard hydraulic pressure table,
and check that the measured values are within the standard
value ranges.
7. If the pressure is not within the standard value, stop the
engine and refer to the hydraulic pressure test diagnosis
table.
8. Remove the O-ring from the port plug and replace it.
9. Remove the special tool, and install the plugs to the
hydraulic pressure ports.
10.Start the engine and check that there are no leaks around
the plugs.
AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-28
STANDARD HYDRAULIC PRESSURE TABLE
NOTE: When the torque converter pressure is measured, the engine speed should be 1,500 r/min or less.
HYDRAULIC PRESSURE TEST DIAGNOSIS TABLE
MEASUREMENT
CONDITIONSSTANDARD HYDRAULIC PRESSURE kPa
SELECT-
OR
LEVER
POS’N SHIFT
RANGE
POSITIO
NENGINE
SPEED
(r/min)UNDERDRIVE
CLUTCH
PRESSURE
[UD]REVERSE
CLUTCH
PRESSURE
[RV]OVERDRIVE
CLUTCH
PRESSURE
[OD]DIRECT
CLUTCH
PRESSURE
[DIR]LOW-
REVERSE
BRAKE
PRESSURE
[LR]SECOND
BRAKE
PRESSURE
[2ND]TORQUE
CONVERTER
PRESSURE
[DR]
P2,500260 360260 360
R Rev. 2,500
12701770 12701770 500 730
N
2,500260 360 220 360
Spo rt
mode1st 2,500 980
1050 980 1050 500 730
2nd 2,500 980
1050 980 1050 500 730
3rd 2,500 780
900 780 900 450 720
4th 2,500 780
900 780 900 780 880 450 720
5th 2,500
780 900 780 880 780 880 450 720
SYMPTOM PROBABLE CAUSE
All hydraulic pressures are high. Malfunction of the regulator valve
All hydraulic pressures are low. Malfunction of the oil pump
Clogged internal oil filter
Clogged oil cooler
Malfunction of the regulator valve
Malfunction of the relief valve
Incorrect valve body installation
Improperly installed solenoid valves
Damaged solenoid valve O-rings
Hydraulic pressure is abnormal
in reverse gear only.Malfunction of the regulator valve
Clogged orifice
Incorrect valve body installation
Hydraulic pressure is abnormal
in 3rd or 4th gear only.Malfunction of the overdrive solenoid valve
Malfunction of the overdrive pressure control valve
Malfunction of the regulator valve
Malfunction of the switch valve
Clogged orifice
Incorrect valve body installation
AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-35
SYMPTOM CHART M1231008000277
During diagnosis, a DTC code associated with
other system may be set when the ignition switch
is turned on with connector(s) disconnected. On
completion, confirm all systems for DTC code(s).
If DTC code(s) are set, erase them all.
SYMPTOM INSPECTION
PROCEDURE NO.REFERENCE
PA G E
Communication with diagnostic
tool is not possibleCommunication with all systems
is impossible- Group 13B
Symptom
Procedures
13A-539.
Communication with the
A/T-ECU only is impossible- Group 13B
Symptom
Procedures
13A-541.
Driving impossible Engine does not start 1
P.23A-218
Does not move forward 2
P.23A-220
Does not move backward 3
P.23A-223
Does not move (forward and
backward)4
P.23A-226
Malfunction when moving
selector into gearEngine stalls when moving
selector lever from "N" to "D" or
"N" to "R"5
P.23A-227
Shift shock when shifting from
"N" to "D" and long delay6
P.23A-229
Shift shock when shifting from
"N" to "R" and long delay 7
P.23A-232
Shift shock when shifting from
"N" to "D" and "N" to "R" and
long delay 8
P.23A-235
Malfunction when shifting Shift shock and slipping 9
P.23A-236
Does not shift properly Early or late shifting in all gears 10
P.23A-239
Early or late shifting in some
gears11
P.23A-242
Does not shift No diagnostic trouble codes 12
P.23A-244
Malfunction while driving Poor acceleration 13
P.23A-248
Vibration 14
P.23A-250
Shift switch assembly system 15
P.23A-252
Shift position indicator light system
P.23A-269
AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-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-ECUCircuit 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
AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-37
STEP 1. Using diagnostic tool MB991958, check data list
item 7: Transmission Fluid Temperature Sensor.
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
80C.
(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.
AUTOMATIC TRANSMISSION DIAGNOSIS
AUTOMATIC TRANSMISSION23A-41
STEP 6. Using diagnostic tool MB991958, check data list
item 7: Transmission Fluid Temperature Sensor.
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
80C.
(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 : Replace the A/T-ECU.
STEP 7. Check A/T control solenoid valve assembly
connector B-108 for loose, corroded or damaged
terminals, or terminals pushed back in the connector.
Q: Are the connector and terminals in good condition?
YES : Go to Step 8.
NO : Repair or replace the damaged components. Refer to
GROUP 00E, Harness Connector Inspection
P.00E-2.