DTC P0731

BHE050201026W14

DTC P0731

Gear 1 incorrect (incorrect gear ratio detected)

DETECTION CONDITION

• TCM monitors rotation ratio of the parking gear rotation compared to reverse and high clutch drum rotation when the following monitoring conditions are met. If the rotation ratio is 2.283 or less, or 3.287 or more, the TCM determines that there is malfunction.
Monitoring condition:
– 2 s or more after shifting to D range
– Vehicle speed 10 km/h {6 mph} or more.
– Engine speed 1,000 rpm or more
– Turbine speed 400 rpm or more
– Ratio between engine speed and turbine speed less than 1.1
– Throttle opening angle 12.5% or more.
– Engine torque 80 N·m {8.2 kgf·m, 59 ft·lbf} or more
– ATF temperature within 20-150 °C {68-302 °F}
– None of the following are present: DTC P0705, P0706, P0712, P0713, P0715, P0720, P0753, P0758, P0763, P0768, P0960, U0073, U0100.

Diagnostic support note:

• This is a continuous monitor (CCM).
• MIL does not illuminate.
• AT warning light does not illuminates.
• PENDING CODE is not available.
• FREEZE FRAME DATA is available.
• DTC stored in the TCM memory.

POSSIBLE CAUSE

• ATF level low
• Deteriorated ATF
• Shift solenoid B, C, or F malfunction
• Pressure control solenoid malfunction
• Line pressure low
• Low clutch slipping
• Low one-way clutch slipping
• Control valve malfunction
• Oil pump malfunction
• TCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN RECORDED

• Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2

VERIFY RELATED REPAIR INFORMATION AVAILABILITY

• Verify related Service Bulletins and/or on-line repair information availability.
• Is any related repair information available?
Yes
Perform repair or diagnosis according to the available repair information.
• If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3

INSPECT ATF CONDITION

• Inspect ATF condition.
• Is it normal?
Yes
Go to the next step.
No
Replace ATF, then go to Step 10.
4

INSPECT ATF LEVEL

• Start the engine.
• Warm up AT.
• Is the ATF level within the specification?
Yes
Go to the next step.
No
Add ATF to the specified level, then go to Step 10.
5

INSPECT SHIFT SOLENOID VALVE B, C AND F

• Inspect the shift solenoid valves B, C and F.
• Are the shift solenoid valves normal?
Yes
Go to the next step.
No
Replace the shift solenoid valve, then go to Step 10.
6

INSPECT LINE PRESSURE

• Start the engine.
• Measure each line pressure.

Specification

D, M range

Idle: 320-450 kPa {3.3-4.6 kgf/cm2,

46-65 psi}

Stall: 1,130-1,330 kPa {11.5-13.6 kgf/cm2, 164-193 psi}

R position

Idle: 380-580 kPa {3.9-5.9 kgf/cm2,

55-84 psi}

Stall: 1,470-1,700 kPa {15.0-17.3 kgf/cm2, 213-247 psi}

P, N position

Idle: 380-580 kPa {3.9-5.9 kgf/cm2,

55-84 psi}

• Are the line pressure measurements within the specifications?
Yes
Go to the next step.
No
Inspect or replace the applicable part according to the line pressure test results, then go to Step 10.
7

INSPECT STALL SPEED

• Measure the stall speed in D range.

Specification

2,400-2,900 rpm

• Is the stall speed within the specification?
Yes
Go to the next step.
No
Inspect or replace the applicable part according to the stall test result, then go to Step 10.
8

INSPECT FREQUENCY OF TURBINE SENSOR WHEN DRIVING VEHICLE

• Turn the ignition switch to the LOCK position.
• Connect the WDS or equivalent.
• Start the engine.
• Measure the frequency of the turbine sensor while driving the vehicle under the following conditions:
– Vehicle speed (VSS PID): 20 km/h {12 mph}
– Drive in D range, 1GR
• Is the turbine sensor frequency approx. 1,100 Hz?
Yes
Go to Step 10.
No
Go to the next step.
9

INSPECT EACH SHIFT VALVE AND RETURN SPRING CONDITION OF CONTROL VALVE

• Turn the ignition switch to the LOCK position.
• Remove the control valve body.
• Disassemble the control valve body.
• Inspect the following:
– Each valve condition
– Each return spring condition
– Oil passage clogging
• Is the control valve body normal?
Yes
Replace the automatic transmission, then go to the next step.
No
Repair or replace any malfunctioning shift valves and/or return springs, then go to the next step.
10

VERIFY TROUBLESHOOTING OF DTC P0731 COMPLETED

• Make sure to reconnect all disconnected connectors.
• Clear DTC using the WDS or equivalent.
• Start the engine.
• Warm up AT.
• Drive the vehicle under the following conditions at least 4 times for 1 s or more.
– ATF temperature: 20 °C {68 °F} or more
– Drive in D range, 1GR
– Throttle opening angle (TOHP PID): 12.5% or more
– Vehicle speed (VSS PID): 10 km/h {6 mph} or more
• Is the same DTC present?
Yes
Replace the TCM, then go to the next step.
No
Go to the next step.
11

VERIFY AFTER REPAIR PROCEDURE

• Perform the "After Repair Procedure".
• Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.