DTC P0730 Incorrect Gear Ratio: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

• Acceleration is poor during standing start.
• Shift control malfunction
• Engine speed increases abruptly.

1. CHECK TRANSMISSION FLUID. 

   Check the amount of ATF. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>ADJUSTMENT . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>ADJUSTMENT .

   Is the check result OK?

   • Yes  : Go to 2. 
   • No  : Adjust the amount of ATF. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>ADJUSTMENT . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>ADJUSTMENT .
2. CHECK TRANSMISSION FLUID. 

   Check the condition of ATF. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>CONDITION CHECK . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>CONDITION CHECK .

   Is the check result OK?

   • Yes  : Go to 3. 
   • No  : Check according to the "Corrective action" of ATF (CVTF) "CONDITION CHECK". Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>CVTF>CONDITION CHECK . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>CVTF>CONDITION CHECK .
3. CHECK INPUT SIGNAL FOR TCM. 
   1. Lift up the vehicle.
   2. Start the engine.
   3. Warm up until the ATF temperature reaches to 40 - 70°C (104 - 158°F).
   4. Depress the brake pedal, and shift the select lever to "D" range.
   5. Shift the select lever to "P" range.
   6. Stabilize the engine speed at idle.
   7. Read the data of [Actual Secondary Pressure] using Subaru Select Monitor.

   Is [Actual Secondary Pressure] 0.5 - 1.5 MPa?

   • Yes  : Go to 4. 
   • No  : Perform the diagnosis according to DTC P0841. Ref. to TRANSMISSION (DIAGNOSTICS)>Diagnostic Procedure with Diagnostic Trouble Code (DTC)>DTC P0841 TRANSMISSION FLUID PRESSURE SENSOR/SWITCH "A" CIRCUIT RANGE/PERFORMANCE .
4. CHECK INPUT SIGNAL FOR TCM. 
   1. Set the select lever to "D" range.
   2. Release the brake pedal to stabilize the engine speed and front wheel speed.
   3. Read the data of [Actual Gear Ratio] using Subaru Select Monitor.

   Is [Actual Gear Ratio] as follows?

   • Non-turbo model

     1.5 - 2.6

   • Turbo model

     2.0 - 2.4

   • Yes  : Go to 5. 
   • No  : Go to  6.
5. CHECK INPUT SIGNAL FOR TCM. 
   1. Set the select lever to "D" range.
   2. Slowly increase the speed to 40 km/h (25 MPH) and keep the constant speed.
   3. Read the data of [Actual Gear Ratio] using Subaru Select Monitor.

   Is [Actual Gear Ratio] as follows?

   • Non-turbo model

     0.5 - 0.9

   • Turbo model

     0.5 - 0.8

   • Yes  : Go to 6. 
   • No  : Replace the transmission assembly. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Automatic Transmission Assembly . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Automatic Transmission Assembly .
6. DRIVING CHECK BY INSPECTION MODE. 
   1. Turn the ignition switch to OFF.
   2. Perform a drive check based on the "Inspection Mode". Ref. to TRANSMISSION (DIAGNOSTICS)>Inspection Mode .

   Does the AT OIL TEMP light blink and is DTC P0730 displayed?

   • Yes  : Replace the transmission assembly. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>Automatic Transmission Assembly . Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR690)>Automatic Transmission Assembly .
   • No  : Current condition is normal. It is possible that temporary poor contact occurs.