U151E AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–85
AX
SYSTEM DESCRIPTION
The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th
or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical
problems of the shift solenoid valves, valve body or automatic transaxle (clutch, brake or gear etc.).
MONITOR DESCRIPTION
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input
shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the
actual gear position (1st, 2nd, 3rd, 4th or 5th gear position). When the gear position commanded by the
ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
DTC P0771Shift Solenoid "E" Performance (Shift Solenoid
Va l v e S R )
DTC No. DTC Detection Condition Trouble Area
P0771The gear required by the ECM does not match the
actual gear when driving (2-trip detection logic)• Shift solenoid valve SR remains open or closed
• Valve body is blocked
• Automatic transaxle (clutch, brake or gear etc.)
Related DTCsP0771:
Shift solenoid valve SR/Rationality check
Required sensors/ComponentsShift solenoid valve SR, Speed sensor (NT), Speed sensor (NC), Crankshaft
position sensor (NE)
Frequency of operation Continuous
DurationOFF malfunction (A)
1 sec.
OFF malfunction (B)
3.5 sec.
ON malfunction (A)
Continuous
ON malfunction (B) and (C)
0.8 sec.
MIL operation 2 driving cycles
Sequence of operation None
The monitor will run whenever this DTC is not presentP0115 - P0118 (ECT sensor)
P0125 (Insufficient ECT for closed loop)
P0500 (VSS)
P0748, P0778, P0798 (Shift solenoid valve (range))
ECT (Engine coolant temperature) 10
C (50F) or more
Transmission range"D"
TFT (Transmission fluid temperature) -20
C (-4F) or more
TFT sensor circuitNot circuit malfunction
ECT sensor circuitNot circuit malfunction
Turbine speed sensor circuit Not circuit malfunction
Intermediate shaft speed sensor circuit Not circuit malfunction
Output speed sensor circuit Not circuit malfunction
Shift solenoid valve SL1 circuit Not circuit malfunction
Shift solenoid valve SL2 circuit Not circuit malfunction
U151E AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–13
AX
MECHANICAL SYSTEM TESTS
1. PERFORM MECHANICAL SYSTEM TESTS
(a) Measure the stall speed.
The object of this test is to check the overall
performance of the transaxle and engine by
measuring the stall speeds in the D position.
NOTICE:
• Driving test should be done on a paved road
(a nonskid road).
• Perform the test at the normal operating ATF
(Automatic Transmission Fluid) temperature
50 to 80
C (122 to 176F).
• Do not continuously run this test for longer
than 10 seconds.
• To ensure safety, do this test in a wide, clear
level area which provides good traction.
• The stall test should always be carried out in
pairs. One technician should observe the
conditions of wheels or wheel stoppers
outside the vehicle while the other is doing
the test.
(1) Chock the 4 wheels.
(2) Connect the intelligent tester together with the
CAN VIM (controller area network vehicle
interface module) to the DLC3.
(3) Fully apply the parking brake.
(4) Keep your left foot pressed firmly on the brake
pedal.
(5) Start the engine.
(6) Shift into the D position. Press all the way down
on the accelerator pedal with your right foot.
(7) Quickly read the stall speed at this time.
Stall speed:
2,300 +- 150 rpm
Evaluation:
Problem Possible cause
(a) Stall engine speed is low in D position• Engine power output may be insufficient
• Stator one-way clutch not operating properly
HINT:
If the value is less than the specified value by 600 rpm or more, the
torque converter could be faulty.
(b) Stall engine speed is high in D position• Line pressure is too low
• Forward clutch slipping
• U/D (Underdrive) brake slipping
• U/D (Underdrive) one-way clutch is not operating properly
• No.1 one-way clutch not operating properly
• Improper fluid level
AX–14U151E AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEM
AX
(b) Measure the time lag.
(1) When the shift lever is shifted while the engine is
idling, there will be a certain time lapse or lag
before the shock can be felt. This is used for
checking the condition of the clutch and brake.
NOTICE:
• Perform the test at the normal operating
ATF (Automatic Transmission Fluid)
temperature: 50 to 80
C (122 to 176F).
• Be sure to allow 1 minute interval between
tests.
• Perform the test three times, and measure
the time lags. Calculate the average value
of the three time lags.
• When conducting stall test, do not
continue more than 10 seconds.
(2) Connect the intelligent tester together with the
CAN VIM (controller area network vehicle
interface module) to the DLC3.
(3) Fully apply the parking brake.
(4) Start and warm up the engine and check idle
speed.
Idle speed:
approx. 700 rpm (In N position and A/C
OFF)
(5) Shift the lever from N to D position. Using a stop
watch, measure the time from when the lever is
shifted until the shock is felt.
Time lag:
N
D less than 1.2 seconds
(6) In the same way, measure the time lag for N
R.
Time lag:
N
R less than 1.5 seconds
Evaluation (If N
D or N R time lag is longer than the specified):
Problem Possible cause
N
D time lag is longer• Line pressure is too low
• Forward clutch worn
• No.1 one-way clutch is not operating properly
• U/D (Underdrive) one-way clutch is not operating
• U/D (Underdrive) brake worn
N
R time lag is longer• Line pressure is too low
• Reverse clutch worn
• 1st and reverse brake worn
• U/D (Underdrive) brake worn
U151E AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–15
AX
HYDRAULIC TEST
1. PERFORM HYDRAULIC TEST
(a) Measure the line pressure.
NOTICE:
• Perform the test at the normal operating ATF
(Automatic Transmission Fluid) temperature:
50 to 80
C (122 to 176F).
• The line pressure test should always be
carried out in pairs. One technician should
observe the conditions of wheels or wheel
stoppers outside the vehicle while the other
is performing the test.
• Be careful to prevent SST hose from
interfering with the exhaust pipe.
• This Check must be conducted after checking
and adjusting engine.
• Perform under condition that A/C is OFF.
• When conducting stall test, do not continue
more than 10 seconds.
(1) Warm up the ATF (Automatic Transmission
Fluid).
(2) Lift the vehicle up.
(3) Remove the engine under cover.
(4) Connect the intelligent tester together with the
CAN VIM (controller area network vehicle
interface module) to the DLC3.
(5) Remove the test plug A on the transaxle case
front left side and install the SST.
SST 09992-00095 (09992-00231, 09992-
00271)
NOTICE:
There is a difference in installation point
between D position and R position.
(6) Start the engine.
(7) Using intelligent tester, shift to D position and
hold 3rd gear by active test, and measure the
line pressure in idling.
Specified line pressure:
(8) Turn the ignition switch off.
C160153E01
Condition
D position kPa (kgf / cm2, psi)
Idling372 to 412 kPa
(3.8 to 4.2 kgf/cm
2, 54 to 60 psi)
AX–16U151E AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEM
AX
(9) Disconnect the connector of the transmission
wire.
HINT:
Disconnect the connector only when performing
the D position stall test.
(10)Start the engine.
(11)Firmly depress the brake pedal, shift to the D
position, depress the accelerator pedal all the
way down and check the line pressure while the
stall test is performed.
Specified line pressure:
(12)Turn the ignition switch off.
(13)Remove the SST, install the test plug A.
(14)Remove the test plug B, install the SST and
start engine.
SST 09992-00095 (09992-00231, 09992-
00271)
(15)Connect the transmission wire connector,
depress the brake pedal firmly, shift to the R
position and check that the line pressure while
the engine is idling and during the stall test.
Specified line pressure:
(16)Remove the SST, install the test plug B.
(17)Clear the DTC.
Evaluation:
C160154E01
Condition
D position kPa (kgf / cm2, psi)
Stall test931 to 1,031 kPa
(9.5 to 10.5 kgf/cm
2, 135 to 150 psi)
Condition
R position kPa (kgf / cm
2, psi)
Idling672 to 742 kPa
(6.9 to 7.6 kgf/cm
2, 97 to 108 psi)
Stall test1,768 to 1,968 kPa
(18.0 to 20.1 kgf/cm
2, 256 to 285 psi)
Problem Possible cause
Measured values are higher than specified in all positions• Shift solenoid valve SLT defective
• Regulator valve defective
Measured values are lower than specified in all positions• Shift solenoid valve SLT defective
• Regulator valve defective
• Oil pump defective
• U/D (Underdrive) direct clutch defective
Pressure is low in the D position only• D position circuit fluid leak
• Forward clutch defective
Pressure is low in the R position only• R position circuit fluid leak
• Reverse clutch defective
• 1st and reverse brake defective
U151E AUTOMATIC TRANSAXLE – VALVE BODY ASSEMBLYAX–137
AX
6. REMOVE VALVE BODY OIL STRAINER ASSEMBLY
(a) Remove the 3 bolts and oil strainer.
NOTICE:
Be careful when removing the oil strainer as
fluid will come out.
(b) Remove the O-ring from the valve body oil strainer
assembly.
7. REMOVE TRANSMISSION VALVE BODY ASSEMBLY
(a) Support the valve body assembly and remove the
17 bolts and the transmission valve body assembly.
(b) Remove the check ball body and the spring.
(c) Remove the bolt and lock plate from the valve body
assembly.
(d) Remove the shift solenoid valve SL3 and SLT from
the valve body assembly.
C091931
C091932
C091933
C050017
C089112
U151E AUTOMATIC TRANSAXLE – VALVE BODY ASSEMBLYAX–141
AX
(c) Install the oil strainer with the 3 bolts.
Torque: 11 N*m (110 kgf*cm, 8 ft.*lbf)
3. INSTALL TRANSMISSION WIRE
(a) Coat the O-ring with ATF.
(b) Install the ATF temperature sensor with the lock
plate and bolt.
Torque: 6.6 N*m (67 kgf*cm, 58 in.*lbf)
(c) Connect the 7 shift solenoid valve connectors.
4. INSTALL AUTOMATIC TRANSAXLE OIL PAN SUB-
ASSEMBLY
(a) Install the 2 magnets in the oil pan.
(b) Apply seal packing or equivalent to the 18 bolts.
Seal packing:
THREE BOND 2430 or equivalent
(c) Install the oil pan and new gasket with the 18 bolts
to the transaxle case.
Torque: 7.8 N*m (80 kgf*cm, 69 in.*lbf)
NOTICE:
Tighten the bolts within 10 minutes of sealant
application.
5. CONNECT CABLE TO NEGATIVE BATTERY
TERMINAL
6. ADD AUTOMATIC TRANSAXLE FLUID
7. CHECK FLUID LEVEL IN AUTOMATIC TRANSAXLE
(See page AX-123)
8. INSTALL ENGINE UNDER COVER NO.1
9. RESET MEMORY
HINT:
(See page AX-16)
C091931
C091927E04
D030865
C091925
U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–13
AX
MECHANICAL SYSTEM TESTS
1. PERFORM MECHANICAL SYSTEM TESTS
(a) Measure the stall speed.
The object of this test is to check the overall
performance of the transaxle and engine by
measuring the stall speeds in the D position.
NOTICE:
• Driving test should be done on a paved road
(a nonskid road).
• Perform the test at the normal operating ATF
(Automatic Transmission Fluid) temperature
50 to 80
C (122 to 176F).
• Do not continuously run this test for longer
than 10 seconds.
• To ensure safety, do this test in a wide, clear
level area which provides good traction.
• The stall test should always be carried out in
pairs. One technician should observe the
conditions of wheels or wheel stoppers
outside the vehicle while the other is doing
the test.
(1) Chock the 4 wheels.
(2) Connect the intelligent tester together with the
CAN VIM (controller area network vehicle
interface module) to the DLC3.
(3) Fully apply the parking brake.
(4) Keep your left foot pressed firmly on the brake
pedal.
(5) Start the engine.
(6) Shift into the D position. Press all the way down
on the accelerator pedal with your right foot.
(7) Quickly read the stall speed at this time.
Stall speed:
2,600 +- 150 rpm
Evaluation:
Problem Possible cause
(a) Stall engine speed is low in D position• Engine power output may be insufficient
• Stator one-way clutch not operating properly
HINT:
If the value is less than the specified value by 600 rpm or more, the
torque converter could be faulty.
(b) Stall engine speed is high in D position• Line pressure is too low
• Forward clutch slipping
• U/D (Underdrive) brake slipping
• U/D (Underdrive) one-way clutch is not operating properly
• No.1 one-way clutch not operating properly
• Improper fluid level