Subaru Forester 2004 Service Manual page 118

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
7 CHECK MASS AIR FLOW AND INTAKE AIR
TEMPERATURE SENSOR
1) Start and warm-up the engine until engine
coolant temperature is greater than 60°C
(140°F).
2) Place the shift lever in neutral position.
3) Turn the A/C switch to OFF.
4) Turn all accessory switches to OFF.
5) Open the hood.
6) Measure the ambient temperature.
7) Read the data of mass air flow and intake
air temperature sensor signal using Subaru
Select Monitor or the OBD-II general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE". <Ref. to EN(H4DOTC
2.5)-27, Subaru Select Monitor.>
• OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
Check
Subtract the ambient tempera-
ture from intake air tempera-
ture, and is the value −10 —
50°C (14 — 122°F)?
EN(H4DOTC 2.5)-117
ENGINE (DIAGNOSTIC)
Yes
Contact the SUB- Check mass air
ARU dealer. flow and intake air
temperature sen-
NOTE:
sor. <Ref. to
Inspection by DTM
FU(H4DOTC 2.5)-
is required, because
30, Mass Air Flow
probable cause is
and Intake Air
deterioration of mul-
Temperature Sen-
tiple parts.
sor.>
No