Subaru 2002 IMPREZA Service Manual page 868

ENGINE MALFUNCTION INDICATOR LAMP (MIL)
ENGINE (DIAGNOSTICS)
C: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MIL) DOES NOT COME
ON.
• DIAGNOSIS:
• The CHECK ENGINE malfunction indicator lamp (MIL) circuit is open or shorted.
• TROUBLE SYMPTOM:
• When the ignition switch is turned ON (engine OFF), MIL does not come on.
• WIRING DIAGRAM:
LHD
B36
i1
LHD
A7
C6
COMBINATION
METER
A: i10
C: i12
B72
1 2 3 4 5 6
1 2
12 13 14 15 16 17 18 19 20 21 22 23 24
3 4
LHD:
i2
1 2 3 4 5 6 7 8 9 10 11
12 13 14 15 16 17 18 19 20 21 22 23 24
Step
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. 11 (+) — Chassis ground ( − − − − ):
2 CHECK POOR CONTACT.
IGNITION
B72
SWITCH
No.13
4
RHD
AT MT
B38 B36
i3 i1
MT
AT
RHD
i2
1 LHD :16
RHD :13
B37
ECM
B134
B36
1 2
7 8 9 10 11
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
24 25
RHD: i2
1 2 3 4 5 6
10 11 12 13 14 15 16 17 18
22 23 24 25 26 27 28 29 30
EN(w/oOBD)-34
SBF-4
1
B134
3 4 5 6 7 8
26 27 28 29 30 31 32 33 34 35
C: i12
7 8 9
1 2 3 4 5 6
19 20 21
7 8 9 10 11 12 13 14
31 32
Check
Is the voltage less than 1 V?
Does the MIL come on when
shaking or pulling ECM con-
nector and harness?
BATTERY
SBF-1
i1 A:
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6
7 8 9 10 11 12 13 14
i3
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20 21 22
Yes
Go to step 4. Go to step 2.
Repair poor con- Go to step 3.
tact in the ECM
connector.
i10
EN1395
No