Subaru XT 1988 Service Manual page 365

2-7 FUEL INJECTION SYSTEM
TROUBLE CODE (23): AIR FLOW METER
Air flow meter
Control unit
38
~W
**R
12~~--~----------------------------------------J
'@(Blacklill
I
I IBI
I
I W J I
~(BlaCk)
19R
"W, ""R
@(Blackll
III 1\ 1
I
L2·1198
Fig, 87
... 1800 cc model
**.
2700 cc model
Check if trouble code is out-
~
Check terminals of control
unit.
putted in D-check mode.
(See page 56.)
• YES
Disconnect air flow meter con-
Turn ignition switch OFF
nector.
(engine off) .
•
,
C
Remove rubber cover from air
Disconnect test mode
flow meter connector.
connector.
,
Check if resistance between
terminal S of air flow meter
NO
Check if resistance between
I~
Check if terminal 5 is open or
YES
Repair terminal or
I
connector and body is less
1--+
terminal 5 of control unit and
disconnected. harness.
body is less than
10 n.
than 10n.
t
NO
• YES
YES
Replace control unit.
Repair harness.
Check if resistance between
~
Check if ground terminal at
NO
terminal (SR) of connector intake manifold is grounded
~
Repair harness.
and body is less than 10
n.
properly.
, YES , YES
Turn ignition switch ON
Tighten bolt.
(engine off).
t
Check if voltage across termi·
NO
Check if voltage across termi-
~
nal ("W, **R) and body is
----
nal 12 of control unit and
Repair harness.
greater than 10 V.
body is greater than
10
V.
t
YES
, NO
YES
Connect air flow meter con-
Check if terminal 12 is open
nector. or disconnected.
Repair term inal or harness.
,
+
NO
Check if voltage across termi·
NO
Replace control unit.
nals (WI and '(BR) of air flow
meter is 1 - 2V.
t
YES
Replace air flow meter.
J
Disconnect air flow meter from
air cleaner. Blow air into air
~
flow meter to check if voltage Replace air flow meter.
I
between terminals (W) and
(SR) changes.
t
YES
Check if voltage across termi-
YES
Check if terminal 2 is open or
YES
nal 2 (WI of control unit con·
disconnected.
Repair terminal or harness.
nector and body is 1 - 2V.
, NO +
NO
Repair harness.
I
Replace control unit.
82