Subaru Impreza 2004 - Page 358

EN(H4SO)(diag)-52
ENGINE (DIAGNOSTICS)
Malfunction Indicator Light
C: MALFUNCTION INDICATOR LIGHT DOES NOT COME ON.
• DIAGNOSIS:
• The malfunction indicator light circuit is open or shorted.
• TROUBLE SYMPTOM:
• When the ignition switch is turned ON (engine OFF), malfunction indicator light does not come on.
• WIRING DIAGRAM:
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1)Turn the ignition switch to ON.
2)Measure the voltage between ECM connec-
tor and chassis ground.
Connector & terminal
(B134) No. 28 (+) — Chassis ground (
−
−−
−
):
Is the voltage less than 1 V? Go to step 4. Go to step 2.
2 CHECK POOR CONTACT.
Check poor contact by shaking or pulling ECM
connector and harness.
Does the malfunction indicator
light illuminate?
Repair poor con-
tact in ECM con-
nector.
Go to step 3.
EN-01417
1
B72
B134
SBF-4
4
28
ECM
i12
1 2 3 4 5 6
87 9 10 11 12 13 14
B134
1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
24 25 26 27 28 29 30 31 32 33 34 35
B72
34
12
SBF-1
No.13
i2
3412 89 10 11
12 13 14 15 16 17 18 19 20 21 22 23 24
567
i2
21
9
32
1234 56
10 11 12 13 14 15
7
16
23 30
19 20
22 26 27 28 29
8
17
24 31
18
25
B37
i2
i1
i2
B37
14
LHD
LHD
RHD
RHD
B36
E
LHD: 14
*
RHD: 31
*
i1
3412 89 10 11
12 13 14 15 16 17 18 19 20 21 22 23 24
5
6
7
: LHD
: RHD
i11
1234
5
6789
10
A:
C:
i12
i11
C7
A6
COMBINATION
METER
IGNITION
SWITCH
BATTERY
13