AT OIL TEMP Warning Light Display: Inspection

WARNING: This page is about a different car, the 2021 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.

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:

When the ignition switch is turned to ON, the AT OIL TEMP light does not illuminate.
AT OIL TEMP light remains lit after engine start.

CHECK DTC .
Read the DTC of [Transmission] using the Subaru Select Monitor. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC U0155 or U0423 displayed?

Yes: Perform the self-diagnosis of combination meter.

No: Go to 2.
CHECK DTC .
Read the DTC of [Transmission] using the Subaru Select Monitor. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DIAGNOSTIC TROUBLE CODE (DTC) .

Are DTCs other than U0155 and U0423 displayed?

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

No: Go to 3.
CHECK COMBINATION METER .
Read the DTC of [Combination Meter] using the Subaru Select Monitor. 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.
CHECK AT OIL TEMP LIGHT .
Turn the ignition switch to ON.

Does AT OIL TEMP light illuminate and then go off in 2 seconds?

Yes: Go to 5.

No: Perform the self-diagnosis of combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER SYSTEM>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .
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) (IMPREZA MODEL)>BASIC DIAGNOSTIC PROCEDURE .

No: Go to 6.
CHECK DTC .
Read the DTC of [Transmission] using the Subaru Select Monitor. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DIAGNOSTIC TROUBLE CODE (DTC) .

Are any DTCs displayed?

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

No: Go to 7.
CHECK TCM .
Using the Subaru Select Monitor, read data of [ATF Temperature Lamp] in the [Data Monitor] of [Transmission]. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DATA MONITOR .

Is [ON] displayed?

Yes: Go to 8.

No: Perform the self-diagnosis of combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER SYSTEM>OPERATION>SELF-DIAGNOSIS DISPLAY MODE .
CHECK TCM .
Using the Subaru Select Monitor, read data of [ATF Temp.] in the [Data Monitor] of [Transmission]. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DATA MONITOR .

Is the display 130°C or more?

Yes: Go to 9.

No: Check the TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR580 IMPREZA)>TRANSMISSION CONTROL MODULE (TCM) .
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 again after the ATF temperature lowers.