DTC P0731 [AW6A-EL, AW6AX-EL]

id050211801900

DTC P0731

Gear 1 incorrect (incorrect gear ratio detected)

DETECTION CONDITION

•  Incorrect gear ratio detected when following conditions are satisfied while driving:

Monitoring condition:

―  ATF temperature 20 °C {68 °F} or more

―  Driving in 1GR in D range

―  Engine running

―  Accelerator opening angle 10% or more

―  Vehicle speed signal normal

Diagnostic support note:

•  This is a continuous monitor (CCM).

•  The MIL illuminates if the TCM detects the above malfunction condition during the first drive cycle.

•  A PENDING CODE is not available.

•  FREEZE FRAME DATA is available.

•  The AT warning light illuminates.

•  The DTC is stored in the TCM memory.

POSSIBLE CAUSE

•  Deteriorated ATF

•  ATF level low

•  Line pressure malfunction

―  Oil pump malfunction

―  Control valve stuck

•  Stall speed malfunction

―  C1 clutch slipping

―  One-way clutch slipping

•  Solenoid valve malfunction

―  Line pressure control solenoid stuck

―  Shift solenoid D stuck

―  Shift solenoid E stuck

―  Shift solenoid F stuck

•  TCM malfunction

DTC P0731	Gear 1 incorrect (incorrect gear ratio detected)
DETECTION CONDITION	• Incorrect gear ratio detected when following conditions are satisfied while driving: Monitoring condition: ― ATF temperature 20 °C {68 °F} or more ― Driving in 1GR in D range ― Engine running ― Accelerator opening angle 10% or more ― Vehicle speed signal normal Diagnostic support note: • This is a continuous monitor (CCM). • The MIL illuminates if the TCM detects the above malfunction condition during the first drive cycle. • A PENDING CODE is not available. • FREEZE FRAME DATA is available. • The AT warning light illuminates. • The DTC is stored in the TCM memory.
POSSIBLE CAUSE	• Deteriorated ATF • ATF level low • Line pressure malfunction ― Oil pump malfunction ― Control valve stuck • Stall speed malfunction ― C1 clutch slipping ― One-way clutch slipping • Solenoid valve malfunction ― Line pressure control solenoid stuck ― Shift solenoid D stuck ― Shift solenoid E stuck ― Shift solenoid F stuck • TCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA been recorded on the repair order?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related 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.
2		No	Go to the next step.
3	INSPECT ATF CONDITION • Inspect the ATF condition. (See AUTOMATIC TRANSAXLE FLUID (ATF) INSPECTION [AW6A-EL, AW6AX-EL].) • Is it normal?	Yes	Go to the next step.
3		No	Replace the transaxle, then go to Step 8.
4	INSPECT ATF LEVEL • Inspect the ATF level. (See AUTOMATIC TRANSAXLE FLUID (ATF) INSPECTION [AW6A-EL, AW6AX-EL].) • Is it normal?	Yes	Go to the next step.
4		No	Add ATF to the specified level, then go to Step 8.
5	INSPECT LINE PRESSURE • Perform the “Line Pressures Test”. (See MECHANICAL SYSTEM TEST [AW6A-EL, AW6AX-EL].) • Is there any malfunction?	Yes	All ranges: Replace the oil pump, then go to Step 8. Any ranges: Replace the control valve body, then go to Step 8. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [AW6A-EL, AW6AX-EL].)
5		No	Go to the next step.
6	INSPECT STALL SPEED • Perform the “Stall Test”. (See MECHANICAL SYSTEM TEST [AW6A-EL, AW6AX-EL].) • Is there any malfunction?	Yes	Replace the automatic transaxle, then go to Step 8. (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [AW6A-EL, AW6AX-EL].)
6		No	Go to the next step.
7	INSPECT SOLENOID VALVE • Inspect the following solenoid valves: (See SOLENOID VALVE INSPECTION [AW6A-EL, AW6AX-EL].) ― Line pressure control solenoid ― Shift solenoid D ― Shift solenoid E ― Shift solenoid F • Is there any malfunction?	Yes	Replace malfunctioning part according to test result, then go to the next step.
7		No	Go to the next step.
8	VERIFY TROUBLESHOOTING OF DTC P0731 COMPLETED • Make sure to reconnect all the disconnected connectors. • Clear the DTC from the memory using the M-MDS. • Drive the vehicle under the following conditions at least 12 times for more than 1 s: ― ATF temperature (TFT PID): 20 °C {68 °F} or more ― Drive in the D range, 1GR ― Accelerator opening angle (THOP PID): 10% or more • Is same DTC present?	Yes	Replace the TCM, then go to the next step. (See TCM REMOVAL/INSTALLATION [AW6A-EL, AW6AX-EL].)
8		No	Go to the next step.
9	VERIFY AFTER REPAIR PROCEDURE • Perform the “After Repair Procedure”. (See AFTER REPAIR PROCEDURE [AW6A-EL, AW6AX-EL].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [AW6A-EL, AW6AX-EL].)
9		No	DTC troubleshooting completed.