P0731
DTC P0731 GEAR 1 INCORRECT RATIOCOMPONENT LOCATION:
GENERAL DESCRIPTION
The input shaft speed in gear 1 range should be the similar to the value that is what the gear 1 ratio and the output shaft speed are multiplied. For example if the output shaft speed is 1,000 rpm and the gear 1 ratio is 3.789, the input shaft speed may be about 3,789 rpm.
DTC DESCRIPTION
This code is displayed if the input shaft speed does not conform with the value which is what the output shaft speed and the gear 1 ratio are multiplied. This is more probably caused by a mechanical defect of adherence of control valves or a breakdown of solenoid controlled valves etc than an electrical defect.
DTC DETECTING CONDITION
DTC DETECTING CONDITION:
SIGNAL WAVEFORM
SIGNAL WAVEFORM:
MONITOR SCAN TOOL 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: 2700 - 2900 engine rpm
Specification::
OPERATING ELEMENT OF EACH SHIFTING RANGE
OPERATING ELEMENT OF EACH SHIFTING RANGE:
UD/C Underdrive clutch
OD/C Overdrive clutch
2ND/B:2ND brake
LR/B: Low & Reverse brake
REV/C: Reverse clutch
RED/B: Reduction brake
DIR/C: Direct clutch
OWC: One way clutch for sub gear shifting
OWC1: One way clutch for main gear shifting
Stall test procedure in D1 and reason
Procedure
1. Warm up the engine
2. 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
1. If there is no mechanical defaults in A/T, all slippage occurs in torque converter.
2. Therefore, engine revolution is output, but input and output speed revolution must be zero due to wheel's lock.
3. If 1st gear operating part has faults, input speed revolution will be out of specification.
4. 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?
YES > Go to Signal circuit inspection procedure.
NO > Go to Component inspection procedure.
CAUTION:
- Do not let anybody stand in front of or behind the vehicle while this test is being carried out.
- Check the A/T fluid level and temperature and the engine coolant temperature.
- Fluid level: At the hot mark on the oil level gauge.
- Fluid temperature: 80 - 100°C (176 - 212°F).
- Engine coolant temperature: 80 - 100°C (176°F - 212°F).
- Check both rear wheel (left and right).
- Pull the parking brake lever on with the brake pedal fully depressed.
- The throttle should not be left fully open for more than eight seconds.
- 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 tests.
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.
Specification: INPUT SPEED - (OUTPUT SPEED - GEAR RATIO): 200 RPM
Specification:
5. Are INPUT & OUTPUT SPEED SENSOR within specifications?
YES > Go to Component inspection procedure.
NO > 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
COMPONENT INSPECTION:
1. Connect oil pressure gauge to UD and L/R ports.
2. Engine ON.
3. Drive a car with gear position 1 in SPORTS MODE.
4. Compare it with reference data.
Specification
Specification (Part 1):
Specification (Part 2):
Specification (Part 3):
Specification (Part 4):
Specification (Part 5):
5. Is oil pressure value within specification?
YES > Repair AUTO TRANSAXLE (Clutch or brake) as necessary and go to Verification of Vehicle Repair procedure.
NO > 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 SCAN TOOL and select Diagnostic Trouble Codes (DTCs) mode.
2. Using a SCAN TOOL, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present?
YES > Go to the applicable troubleshooting procedure.
NO > System performing to specification at this time.