P0736

DTC P0736 REVERSE GEAR INCORRECT RATIO





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 reverse gear ratio, while the transaxle is engaged in the reverse gear. For example, if the output speed is 1,000 rpm and the reverse gear ratio is 2.480, then the input speed is 2,480 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 reverse gear ratio, while the transaxle is engaged in reverse 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

SIGNAL WAVEFORM
Refer to DTC P0731. P0731

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 "R".
Specification: 2000 - 2700 engine rpm





OPERATING ELEMENT OF EACH SHIFTING RANGE

Stall test procedure in Reverse and reason
Procedure
1. Warm up the engine
2. After positioning the select lever in "R" range, Depress the foot brake pedal fully after that, depress the accelerator pedal to the maximum
The slippage of REVERSE clutch and OR brake can be detected by stall test in R range

Reason for stall test
1. If there is no mechanical defaults in A/T, all slippage occurs in the torque converter.
2. Therefore, engine revolution is output, but input and output speed revolution must be "zero" due to wheel's lock.
3. If reverse clutch and OR brake system (reverse gear operating parts) 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.
Engine coolant temperature: 80 - 100°C.
^ Chock 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 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 "R" gear.
Specification: INPUT SPEED - (OUTPUT SPEED x GEAR RATIO) 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 Vehicle Repair" procedure.

COMPONENT INSPECTION





1. Connect Oil pressure gauge to "RV" and "LR" port.
2. Engine "ON".
3. Drive a car with gear position R.





4. Compare it with reference data as below.
Specification . shown below
The values are subject to change according to vehicle model or condition
5. Is oil pressure value within specification?
YES >>
^ Repair AUTO TRANSAXLE (Clutch or Brake) as necessary and Go to "Verification Vehicle Repair" procedure.
NO >>
^ Replace AUTO TRANSAXLE (BODY CONTROL VALVE faulty) as necessary and Go to "Verification Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR
Refer to DTC P0560. P0760