AT OIL TEMP Warning Light Display: Inspection

Diagnosis: 

• CAN communication is lost with the combination meter.
• Combination meter malfunction
• TCM is in special control mode.
• AT learning is not finished.

Trouble symptom: 

AT OIL TEMP light remains lit after engine start.

1. CHECK DTC  .

   Using the Subaru Select Monitor, read DTC of [transmission]. Ref. to TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC U0155 or U0423 displayed?

   Yes:  Check the combination meter. Ref. to COMBINATION METER (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   No:  Go to  2.

2. CHECK DTC  .

   Using the Subaru Select Monitor, read DTC of [transmission]. Ref. to TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Are DTCs other than U0155 and U0423 displayed?

   Yes:  Perform the diagnosis according to the DTC. Ref. to TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Go to  3.

3. CHECK COMBINATION METER  .

   Using the Subaru Select Monitor, read DTC of [combination meter]. Ref. to COMBINATION METER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Are any DTCs displayed?

   Yes:  Perform the diagnosis according to the DTC. Ref. to COMBINATION METER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Go to  4.

4. CHECK AT OIL TEMP LIGHT  .

   Start the engine.

   Does the AT OIL TEMP light go off?

   Yes:  Current condition is normal. Go back to Basic Diagnostic Procedure. Ref. to TRANSMISSION (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   No:  Go to  5.

5. CHECK DTC  .

   Using the Subaru Select Monitor, read DTC of [transmission]. Ref. to TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Are any DTCs displayed?

   Yes:  Perform the diagnosis according to the DTC. Ref. to TRANSMISSION (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   No:  Go to  6.

6. CHECK TCM  .

   Read the data of [ATF Temperature Lamp] using Subaru Select Monitor. Ref. to TRANSMISSION (DIAGNOSTICS)>DATA MONITOR .

   Is "ON" displayed?

   Yes:  Go to  7.

   No:  Check the combination meter. Ref. to COMBINATION METER (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

7. CHECK TCM  .

   Read the data of [ATF Temp.] using Subaru Select Monitor. Ref. to TRANSMISSION (DIAGNOSTICS)>DATA MONITOR .

   Is the display 130°C or more?

   Yes:  Go to  8.

   No:  Replace the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>TRANSMISSION CONTROL MODULE (TCM) .

8. CHECK ATF TEMPERATURE  .

   Check the real fluid temperature from the transmission case surface temperature.

   Does it clearly differ from the [ATF Temp.] displayed on Subaru Select Monitor?

   Yes:  Perform the diagnosis according to DTC P0712. If there is no problem, perform the diagnosis according to DTC P0713.

   No:  When ATF temperature can be judged as actually high, perform the diagnosis after the ATF temperature lowers.