2004 SUBARU FORESTER Service Repair Manual

bolt pattern buttons warning suspension emergency towing infotainment

Load previous 8 pages

Page 1177 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-79
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Start the engine, a

Page 1178 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-80
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
B: DTC P0031 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)
DTC DETECTING CONDITION:
Immediately at fault rec

Page 1179 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-81
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Does the Subaru Select Moni-
tor or OBD-II general scan tool

EN(H4SO)-81
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC P0031 and
P0037 at the same time?Go to step 2.Go to step 5.
2 CHECK POWER SUPPLY TO FRONT OXY-
GEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between front oxygen
(A/F) sensor connector and engine ground.
Connector & terminal
(B18) No. 4 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 3.Repair the power
supply line.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
main relay and
front oxygen (A/F)
sensor connector
Poor contact in
front oxygen (A/F)
sensor connector
Poor contact in
main relay connec-
tor
3 CHECK GROUND CIRCUIT FOR ECM.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 5 — Chassis ground:
(B136) No. 16 — Chassis ground:Is the resistance less than 5
Ω?Go to step 4.Repair harness
and connector.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ECM and engine
ground terminal
Poor contact in
ECM connector.
Poor contact in
coupling connector
4 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of front oxygen (A/F) sensor
heater current using Subaru Select Monitor or
OBD-II general scan tool.
N
OTE:
Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. to EN(H4SO)-29, Subaru Select Monitor.>
OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the current more than 0.2 A? Repair poor con-
tact connector.
N
OTE:
In this case repair
the following:
Poor contact in
front oxygen (A/F)
sensor connector
Poor contact in
ECM connector.Go to step 5.
5 CHECK INPUT SIGNAL FROM ECM.
1) Start and idle the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 6 (+) — Chassis ground (
−):
(B136) No. 17 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 7.Go to step 6.
6 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 6 (+) — Chassis ground (
−):
(B136) No. 17 (+) — Chassis ground (
−):Is the voltage less than 1 V by
shaking the ECM harness and
connector while monitoring the
value of voltage meter?Repair the poor
contact in ECM
connector.Go to step 7.

Page 1180 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-82
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FRONT OXYGEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between front o

Page 1181 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-83
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
C: DTC P0032 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 1)
DTC DETECTING CONDITION:
Detect as soon as the m

Page 1182 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-84
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage betw

Page 1183 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-85
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
D: DTC P0037 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 2)
DTC DETECTING CONDITION:
Two consecutive driving

Page 1184 of 2870

SUBARU FORESTER 2004 Service Repair Manual EN(H4SO)-86
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connecto

EN(H4SO)-86
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK GROUND CIRCUIT FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B136) No. 16 — Chassis ground:
(B136) No. 5 — Chassis ground:Is the resistance less than 5
Ω?Go to step 2.Repair harness
and connector.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ECM and engine
ground terminal
Poor contact in
ECM connector.
Poor contact in
coupling connector
2 CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of rear oxygen (A/F) sensor
heater current using Subaru Select Monitor or
OBD-II general scan tool.
N
OTE:
Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. to EN(H4SO)-29, Subaru Select Monitor.>
OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the current more than 0.2 A? Repair the con-
nector.
N
OTE:
In this case repair
the following:
Poor contact in
rear oxygen sen-
sor connector
Poor contact in
rear oxygen sen-
sor connecting
harness connector
Poor contact in
ECM connector.Go to step 3.
3 CHECK OUTPUT SIGNAL FROM ECM.
1) Start and idle the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 4 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 6.Go to step 4.
4 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B136) No. 4 (+) — Chassis ground (
−):Does the voltage change
within the range of 1 V by
shaking the ECM harness and
connector while monitoring the
value of voltage meter?Repair the poor
contact in ECM
connector.Go to step 5.
5 CHECK OUTPUT SIGNAL FROM ECM.
1) Disconnect the connector from rear oxygen
sensor.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 4 (+) — Chassis ground (
−):Is the voltage less than 1 V? Replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>Repair battery
short circuit in har-
ness between
ECM and rear oxy-
gen sensor con-
nector. After
repair, replace the
ECM. FU(H4SO)-44,
Engine Control
Module (ECM).>

Load next 8 pages

Page: < prev 1-10 ... 1145-1152 1153-1160 1161-1168 1169-1176 1177-1184 1185-1192 1193-1200 1201-1208 1209-1216 ... 2872 next >

maintenance diagnostic menu wiper fluid coolant level oil level seats