The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 1st gear ratio, while the transaxle is engaged in the 1st gear. For example, if the output speed is 1000 rpm and the 1st gear ratio is 4.497, then the input speed is 4,497 rpm.
DTC DESCRIPTION
This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 1st gear ratio, while the transaxle is engaged in 1st gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.
DTC DETECTING CONDITION
Item
Detecting Condition
Possible cause
DTC Strategy
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1st gear incorrect ratio
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Faulty Input speed sensor
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Faulty output speed sensor
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Faulty UD clutch or LR,RED brake or One way clutch1,2
Enable Conditions
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Engine speed ＞450rpm
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Output speed ＞150rpm
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Shift stage 1st. gear
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Input speed ＞0rpm
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A/T oil temp output ≥ -23°C(-9.4°F)
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11V ≤ Battery Voltage ≤16V
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TRANSAXLE RANGE SWITCH is normal and after 2sec is passed from IG ON
Threshold value
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ㅣinput speed/1st gear ratio - output speedㅣ≥200rpm
Diagnostic Time
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more than 1sec
Fail Safe
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Locked into 3rd gear. (If diagnosis code P0731 is output four times, the transaxle is locked into 3rd gear)
SIGNAL WAVEFORM
MONITOR SCANTOOL DATA
1.
Connect scan tool to data link connector(DLC).
2.
Engine "ON".
3.
Monitor the "ENGINE SPEED, INPUT SPEED SENSOR, OUTPUT SPEED SENSOR, GEAR POSITION" parameter on the scan tool.
4.
Perform the "STALL TEST" with gear position "1"
Specification : 2100~2800 engine rpm
OPERATING ELEMENT OF EACH SHIFTING RANGE
GEAR POSITION
ELEMENT
L/R BRAKE
2ND BRAKE
U/D CLUTCH
O/D CLUTCH
RED BRAKE
DIR CLUTCH
REV CLUTCH
OWC1
OWC2
1st
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2nd
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3rd
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●
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4th
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●
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5th
●
●
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REV
●
●
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N,P
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Low ＆ Reverse Brake is released When the vehicle speed over the 5MPH(7km/h).
Stall test procedure in D1 and reason
Procedure
A.
Warm up the engine.
B.
After positioning the select lever in "D", depress the foot brake pedal fully after that, depress the accelerator pedal to the maximum.
* The slippage of 1st gear operating parts can be detected by stall test in D
Reason for stall test
A.
If there is no mechanical defaults in A/T, all slippages occurrs in torque converter.
B.
Therefore, engine revolution is output, but input and output speed revolution must be "zero" due to wheel's lock.
C.
If 1st gear operating part has faults, input speed revolution will be out of specification.
D.
If output speed revolution is output. It means that the foot brake force is not applied fully. Remeasuring is required.
5.
Is "STALL TEST " within specification?
▶ Go to "Signal circuit inspection" procedure.
▶ Go to "Component inspection" procedure.
caution
1.
Do not let anybody stand in front of or behind the vehicle while this test is being carried out.
2.
Check the A/T fluid level and temperature and the engine coolant temperature.
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Fluid level : At the hot mark on the oil level gauge.
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Fluid temperature : 176 °F~ 212 °F (80~100 °C).
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Engine coolant temperature : 176 °F~ 212 °F (80~100 °C).
3.
Chock both rear wheel(left and right).
4.
Pull the parking brake lever on with the brake pedal fully depressed.
5.
The throttle should not be left fully open for more than eight second.
6.
If carrying out the stall test two or more time, move the select lever to the "N" position and run the engine at 1,000 rpm to let the A/T fluid cool down before carrying out subsequent.
SIGNAL CIRCUIT INSPECTION
1.
Connect Scan tool.
2.
Engine "ON".
3.
Monitor the "INPUT ＆ OUTPUT SPEED SENSOR" parameter on the scan tool.
4.
Accelerate the Engine speed until about 2000 rpm in the 1st gear.
Does "INPUT ＆ OUTPUT SPEED SENSOR" within specifications?
▶ Go to "Component Inspection" procedure.
▶ Check for electrical noise of circuit in INPUT ＆OUTPUT SPEED SENSOR or Replace INPUT ＆ OUTPUT SPEED SENSOR. Repair as necessary and Go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1.
Connect oil pressure gauge to "UD" and "L/R" and "RED" port.
2.
Engine "ON".
3.
Drive a car with gear position 1 in "SPORTS MODE".
4.
Compare it with reference data as below.
Specification : refer to Standard Oil Pressure Table as below
5.
Is oil pressure value within specifications?
▶ Repair AUTO TRANSAXLE(Clutch or Brake) as necessary and Go to "Verification of Vehicle Repair" procedure.
▶ Replace AUTO TRANSAXLE (BODY CONTROL VALVE faulty) as necessary and Go to "Verification of Vehicle Repair " procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1.
Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode.
2.
Using a scantool, Clear DTC.
3.
Operate the vehicle within DTC Enable conditions in General information.
4.
Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System performing to specification at this time.
