FixVault

DTC P0731 (6-Speed A/T)

DTC P0731  : 1st Gear Incorrect Ratio

NOTE: 

DTC Description Confirmed DTC Pending DTC Freeze Frame
P0731 1st Gear Incorrect Ratio      

DTC (A/T)

  1. Problem verification

    - 1. Turn the vehicle to the ON mode.

    - 2. Clear the DTC with the HDS.

    - 3. Test-drive the vehicle in 1st gear in D, at speeds over 7 mph (12 km/h) for at least 12 seconds.

    - 4. Check for Pending or Confirmed DTCs with the HDS.

    DTC Description Confirmed DTC Pending DTC Freeze Frame
    P0731 1st Gear Incorrect Ratio      

    Is DTC P0731 indicated?

    YES 

    The failure is duplicated. Go to step 2.

    NO 

    Intermittent failure, the system is OK at this time. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

  2. 1st clutch pressure check

    - 1. Measure the 1st clutch pressure.

    Is the 1st clutch pressure within the service limit?

    YES 

    The 1st clutch pressure is OK. Faulty 1st clutch. Replace the 1st clutch or the transmission - Refer to: Automatic Transmission Removal and Installation (6-Speed A/T) . If replacing the 1st clutch, clean off any metal debris or excessive clutch material inside the transmission, the ATF hoses, the ATF pipes, and the hydraulic circuit. Then, replace the 1st clutch and the torque converter.

    NO 

    Go to step 3.

  3. 1st clutch hydraulic circuit check

    - 1. Measure the line pressure.

    Is the line pressure within the service limits?

    YES 

    Clogged 1st clutch hydraulic circuit. Clean the 1st clutch hydraulic circuit, or replace the transmission - Refer to: Automatic Transmission Removal and Installation (6-Speed A/T) . If cleaning the 1st clutch hydraulic circuit, clean off any metal debris or excessive clutch material inside the transmission, the ATF hoses, the ATF pipes, and the hydraulic circuit. Then, replace the torque converter.

    NO 

    The 1st clutch hydraulic circuit is OK. Faulty ATF pump or main regulator valve. Replace the main valve body (ATF pump), the regulator valve body (main regulator valve), or the transmission - Refer to: Automatic Transmission Removal and Installation (6-Speed A/T) . If replacing the main valve body or the regulator valve body, clean off any metal debris or excessive clutch material inside the transmission, the ATF hoses, the ATF pipes, and the hydraulic circuit. Then, replace the main valve body or the regulator valve body and the torque converter.