Subaru Legacy 2003 Service Manual page 1922

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CONNECT SUBARU SELECT MONITOR,
AND READ DATA.
1) Turn the ignition switch to OFF.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON and Subaru
Select Monitor switch to ON.
4) Start the engine.
5) Read the data of mass air flow sensor sig-
nal using Subaru Select Monitor.
Is the measured value within the specified
value?
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOSTC)-26, Subaru Select Monitor.>
2 CHECK HARNESS BETWEEN ECM AND
MASS AIR FLOW SENSOR CONNECTOR.
1) Turn the ignition switch to OFF and Subaru
Select Monitor switch to OFF.
2) Disconnect the connector from mass air
flow sensor.
3) Turn the ignition switch to ON and Subaru
Select Monitor switch to ON.
4) Read the data of mass air flow sensor sig-
nal using Subaru Select Monitor.
Does the measured value exceed the spec-
ified value?
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOSTC)-26, Subaru Select Monitor.>
Value
1.3 g/sec (0.172 lb/min) — 240
g/sec (32 lb/min) or 0.3 — 4.58
V
240 g/sec (32 lb/min) or 4.58 V Repair the battery
EN(H4DOSTC)-83
ENGINE (DIAGNOSTICS)
Yes
Even if MI lights Go to step 2.
up, the circuit has
returned to a nor-
mal condition at
this time.
Replace the mass
short circuit in har- air flow sensor.
ness between
mass air flow sen-
sor and ECM con-
nector. After
repair, replace the
ECM.
No