Subaru Impreza 2004 Service Manual page 223

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
• RHD model
MAIN RELAY
4
6
5
3
2
1
B47
E
B72
1 2
3 4
Step
1 CHECK INPUT SIGNAL FOR ECM.
1)Turn the ignition switch to OFF.
2)Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 10 (+) — Chassis ground ( − − − − ):
2 CHECK HARNESS BETWEEN ECM AND
MAIN FUSE BOX CONNECTOR.
1)Disconnect the battery negative terminal,
and then disconnect the positive terminal.
2)Disconnect the connector from ECM.
3)Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B137) No. 10 — Chassis ground:
DATA LINK CONNECTOR
No.11
A :
B134
D : B136
ECM
E : B137
C :
B84
B22
E3
E
B47 B22
1 2 3 4
1 2
5 6 7 8
3 4
5 6 9 10 11 12
13 14 15 16
EN(H4DOTC)(diag)-302
IGNITION
B72
SWITCH
SBF-4
4 1
B134
1 2 3 4 5 6 7
1 2
8 9 10 11 12 13 14 15
8 9 10 11 12
16 17 18 19 20 21 22
17 18 19 20 21
B136
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17
Check
Is the voltage more than 10 V? Repair the poor
Is the resistance less than 10
Ω?
SBF-5
BATTERY
SBF-1
B137 B84
3 4 1 2 3 4
5 6 7
10 11 12 13 14 15 16 17
13 14 15 16
22 23 24 22 23 24 25 26
Yes
Go to step 2.
contact in ECM
connector.
Repair the ground Go to step 3.
short circuit in har-
ness between
ECM connector
and battery termi-
nal.
E
5 6 7 8 9
18 19 20 21
27 28 29 30 31
EN-01293
No