Subaru 2002 IMPREZA Service Manual page 1297

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK ANY OTHER DIAGNOSTIC TROU-
BLE CODE (DTC) ON DISPLAY.
2 CHECK ENGINE COOLING SYSTEM.
NOTE:
Check the following items.
•Thermostat open stuck
•Coolant level
•Coolant freeze
•Tire diameter
Check
Is any other DTC displayed?
Is there a fault in engine cool-
ing system?
EN(TURBO)-137
ENGINE (DIAGNOSTICS)
Yes
Inspect the rele- Go to step 2.
vant DTC using
"List of Diagnostic
Trouble Code
(DTC)". <Ref. to
EN(TURBO)-75,
List of Diagnostic
Trouble Code
(DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0125.
Replace the ther- Replace the
mostat. <Ref. to engine coolant
CO-37, Thermo- temperature sen-
stat.> sor. <Ref. to
FU(TURBO)-29,
Engine Coolant
Temperature Sen-
sor.>
No