P0731

P0731

Component Location:

General Description
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 2.842, then the input speed is 2842 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:

Specification
Input shaft & Output shaft speed sensor
- Type : Hall sensor
- Current consumption : 22 mA (MAX)
- Sensor body and sensor connector have been unified as one.

Signal Waveform:

Monitor Scantool Data
1. Connect scantool to data link connector (DLC)
2. Engine "ON".
3. Monitor the "ENGINE SPEED, INPUT SPEED SENSOR, OUTPUT SPEED SENSOR, GEAR POSITION" parameter on the scantool
4. Perform the "STALL TEST" with gear position "1"

Specification : 2000-2700 engine rpm









CAUTION: 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, every slippage occur 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.
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 specifications?

YES
a. Go to "W/Harness Inspection" procedure

NO
a. 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.
- Fluid level : At the hot mark on the oil level gauge.
- Fluid temperature : 80-100 °C.
- Engine coolant temperature : 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 Scantool
2. Engine "ON".
3. Monitor the "INPUT & OUTPUT SPEED SENSOR" parameter on the scantool
4. Accelerate the Engine speed until about 2000 rpm in the 1st gear

Specification : INPUT SPEED - (OUTPUT SPEED • GEAR RATIO) ≤ 200 RPM






5. Are "INPUT & OUTPUT SPEED SENSOR" within specifications?

YES
a. Go to "Component Inspection" procedure

NO
a. Check for electrical noise of circuit in INPUT & OUTPUT SPEED SENSOR or Replace INPUT & OUTPUT SPEED SENSOR. Repair as necessary and Go to "Verification Vehicle Repair" procedure

Component Inspection






1. Connect Oil pressure gauge to "UD" and "L/R" port.
2. Engine "ON".
3. Drive a car with gear position 1 in "SPORTS MODE".
4. Compare it with reference data as below

Specification :






5. Is oil pressure value within specifications?

YES
a. Repair AUTO TRANSAXLE (Clutch or Brake) as necessary and Go to "Verification Vehicle Repair" procedure.

NO
a. Replace AUTO TRANSAXLE (BODY CONTROL VALVE faulty) as necessary and Go to "Verification Vehicle Repair" procedure.

Verification of Vehicle Repair
After a repair, it may be necessary to check that fault is properly rectified.
1. Connect scan tool 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?

YES
a. Go to the applicable troubleshooting procedure.

NO
a. System performing to specification at this time.