2004 SUBARU FORESTER sensor

EN(H4DOTC)-77
ENGINE (DIAGNOSTIC)
List of Diagnostic Trouble Code (DTC)
P0507 Idle Control System RPM Higher
Than Expected HIGHER THAN EXPECTED, Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P0508 Idle Control System Circuit Low CUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0509 Idle Control System Circuit High CUIT HIGH, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0512 Starter Request Circuit Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0513 Incorrect Immobilizer Key Procedure with Diagnostic Trouble Code (DTC).>
P0519 Idle Control System Malfunction
(Fail-Safe) FUNCTION (FAIL-SAFE), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P0545 Exhaust Gas Temperature Sensor
Circuit Low - Bank 1 SENSOR CIRCUIT LOW - BANK 1, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
P0546 Exhaust Gas Temperature Sensor
Circuit High - Bank 1 SENSOR HIGH - BANK 1, Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P0558 Generator Circuit Low Input INPUT, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0559 Generator Circuit High Input INPUT, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0600 Serial Communication Link Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0604 Internal Control Module Random
Access Memory (RAM) Error READ ONLY MEMORY (ROM) ERROR, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>
P0691 Cooling Fan 1 Control Circuit Low CUIT LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0692 Cooling Fan 1 Control Circuit High CUIT HIGH, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0700 Transmission Control System (MIL
Request) TEM (MIL REQUEST), Diagnostic Procedure with Diagnostic Trouble Code
(DTC).>
P0851 Neutral Switch Input Circuit Low CUIT LOW (AT MODEL), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).> or SWITCH INPUT CIRCUIT LOW (MT MODEL), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P0852 Neutral Switch Input Circuit High CUIT HIGH (AT MODEL), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).> or SWITCH INPUT CIRCUIT HIGH (MT MODEL), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1086 Tumble Generated Valve Position
Sensor 2 Circuit Low POSITION SENSOR 2 CIRCUIT LOW, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>
P1087 Tumble Generated Valve Position
Sensor 2 Circuit High POSITION SENSOR 2 CIRCUIT HIGH, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>
P1088 Tumble Generated Valve Position
Sensor 1 Circuit Low POSITION SENSOR 1 CIRCUIT LOW, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).> DTC Item NOTE

EN(H4DOTC)-78
ENGINE (DIAGNOSTIC)
List of Diagnostic Trouble Code (DTC)
P1089 Tumble Generated Valve Position
Sensor 1 Circuit High POSITION SENSOR 1 CIRCUIT HIGH, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>
P1090 Tumble Generated Valve System 1
(Valve Open) SYSTEM 1 (VALVE OPEN), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P1091 Tumble Generated Valve System 1
(Valve Close) SYSTEM 1 (VALVE CLOSE), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P1092 Tumble Generated Valve System 2
(Valve Open) SYSTEM 2 (VALVE OPEN), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P1093 Tumble Generated Valve System 2
(Valve Close) SYSTEM 2 (VALVE CLOSE), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P1094 Tumble Generated Valve Signal 1
Circuit Malfunction (Open) SIGNAL 1 CIRCUIT MALFUNCTION (OPEN), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1095 Tumble Generated Valve Signal 1
Circuit Malfunction (Short) SIGNAL 1 CIRCUIT MALFUNCTION (SHORT), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1096 Tumble Generated Valve Signal 2
Circuit Malfunction (Open) SIGNAL 2 CIRCUIT MALFUNCTION (OPEN), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1097 Tumble Generated Valve Signal 2
Circuit Malfunction (Short) SIGNAL 2 CIRCUIT MALFUNCTION (SHORT), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1110 Atmospheric Pressure Sensor Cir-
cuit Malfunction (Low Input) SOR CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1111 Atmospheric Pressure Sensor Cir-
cuit Malfunction (High Input) SOR CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1152 O
2 Sensor Circuit Range/Perfor-
mance (Low) (Bank 1 Sensor 1) PERFORMANCE (LOW) (BANK 1 SENSOR 1), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1153 O
2 Sensor Circuit Range/Perfor-
mance (High) (Bank 1 Sensor 1) PERFORMANCE (HIGH) (BANK 1 SENSOR 1), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1301 Misfire Detected (High Tempera-
ture Exhaust Gas) PERATURE EXHAUST GAS), Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P1312 Exhaust Gas Temperature Sensor
Malfunction CUIT RANGE/PERFORMANCE, Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).>
P1518 Starter Switch Circuit Low Input INPUT, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P1544 Exhaust Gas Temperature Too
High TOO HIGH, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P1560 Back-Up Voltage Circuit Malfunc-
tion MALFUNCTION, Diagnostic Procedure with Diagnostic Trouble Code
(DTC).>
P1570 ANTENNA nostic Trouble Code (DTC).>
P1571 Reference Code Incompatibility nostics Procedure with Diagnostic Trouble Code (DTC).> DTC Item NOTE

EN(H4DOTC)-82
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
C: DTC P0031 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode .
WIRING DIAGRAM:
EN-02320
BATTERYMAIN RELAYSBF-5
B47 1 2 3 5 4 6
E
E
B100F2
14LHD
RHD
LHD
RHD
B100
F2
F60
E3
20
3
RHD
RHD6
72
3
33
26
25
ECMB134
: LHD: LHD
B21: RHD: RHD
1
4 2
3
B262
FRONT OXYGEN
(A/F) SENSOR
3412
56
123
4
56
78
9
1011 12
1314 15 16
B21
F60
B47
B262
B134
F2
LHD LHD
1234
56 7
82 1
94 310
24 22 23 25 11 12 13 14 15
26 27
2816 17
18 19 20 21
33 34 29
32 30 31
1234 5678910 11 12 13 14 15 16 17 18 19 20
: LHDE2: RHD

EN(H4DOTC)-83
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, and warm-up the engine.
2) Turn the ignition switch to OFF.
3) Disconnect the connector from ECM and
front oxygen (A/F) sensor.
4) Measure the resistance of harness
between ECM and front oxygen (A/F) sensor
connector.
Connector & terminal
(B134)No. 2 — (B262)No. 2:
(B134)No. 3 — (B262)No. 2:Is the resistance less than 1
Ω?Go to step 2.Repair the open
circuit in harness
between ECM and
front oxygen (A/F)
sensor connector.
2 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
Measure the resistance of harness between
ECM and front oxygen (A/F) sensor connector.
Connector & terminal
(B134) No. 33 — (B262) No. 4:
(B134) No. 26 — (B262) No. 3:Is the resistance less than 1
Ω?Go to step 3.Repair the open
circuit in harness
between ECM and
front oxygen (A/F)
sensor connector.
3 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
Measure the resistance of harness between
main relay and front oxygen (A/F) sensor con-
nector.
Connector & terminal
(B47) No. 4 — (B262) No. 1:Is the resistance less than 1
Ω?Go to step 4.Repair the open
circuit in harness
between ECM and
front oxygen (A/F)
sensor connector.
4 CHECK FRONT OXYGEN (A/F) SENSOR.
Measure the resistance between front oxygen
(A/F) sensor connector terminals.
Te r m i n a l s
No. 2 — No. 1:Is the resistance less than 5
Ω?Go to step 5.Replace the front
oxygen (A/F) sen-
sor. FU(H4DOTC)-45,
Front Oxygen (A/
F) Sensor.>
5 CHECK POOR CONTACT.
Check poor contact in ECM and front oxygen
(A/F) sensor connector. Is there poor contact in ECM or
front oxygen (A/F) sensor con-
nector?Repair the poor
contact in ECM
and front oxygen
(A/F) sensor.Replace the front
oxygen (A/F) sen-
sor. FU(H4DOTC)-45,
Front Oxygen (A/
F) Sensor.>

EN(H4DOTC)-84
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
D: DTC P0031 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)
DTC DETECTING CONDITION:
Detect as soon as the malfunction occurs.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode .
WIRING DIAGRAM:
EN-02320
BATTERYMAIN RELAYSBF-5
B47 1 2 3 5 4 6
E
E
B100F2
14LHD
RHD
LHD
RHD
B100
F2
F60
E3
20
3
RHD
RHD6
72
3
33
26
25
ECMB134
: LHD: LHD
B21: RHD: RHD
1
4 2
3
B262
FRONT OXYGEN
(A/F) SENSOR
3412
56
123
4
56
78
9
1011 12
1314 15 16
B21
F60
B47
B262
B134
F2
LHD LHD
1234
56 7
82 1
94 310
24 22 23 25 11 12 13 14 15
26 27
2816 17
18 19 20 21
33 34 29
32 30 31
1234 5678910 11 12 13 14 15 16 17 18 19 20
: LHDE2: RHD

EN(H4DOTC)-85
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 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
(B262) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 2.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
 CHECK POOR
CONTACT OF
FRONT OXYGEN
(A/F) SENSOR.
 Poor contact in
main relay connec-
tor
2 CHECK GROUND CIRCUIT FOR ECM.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 6 — Chassis ground:
(B134) No. 7 — Chassis ground:Is the resistance less than 5
Ω?Go to step 3.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and engine
ground cable
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
3 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
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”. 33, 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 4.
4 CHECK OUTPUT SIGNAL FROM ECM.
1) Start and idle the engine.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 2 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 6.Go to step 5.
5 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 2 (+) — Chassis ground (
−):Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with voltage
meter?Repair the poor
contact in ECM
connector.Go to step 6.

EN(H4DOTC)-86
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 3 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 8.Go to step 7.
7 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 3 (+) — Chassis ground (
−):Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with voltage
meter?Repair the poor
contact in ECM
connector.Go to step 8.
8 CHECK FRONT OXYGEN (A/F) SENSOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance between front oxy-
gen (A/F) sensor connector terminals.
Te r m i n a l s
No. 2 — No. 1:Is the resistance less than 10
Ω?Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open or ground
short circuit in har-
ness between front
oxygen (A/F) sen-
sor and ECM con-
nector
 Poor contact in
front oxygen (A/F)
sensor connector
 Poor contact in
ECM connector.Replace the front
oxygen (A/F) sen-
sor. FU(H4DOTC)-45,
Front Oxygen (A/
F) Sensor.> Step Check Yes No

EN(H4DOTC)-87
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
E: DTC P0032 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 1)
DTC DETECTING CONDITION:
Detect as soon as the malfunction occurs.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode .
WIRING DIAGRAM:
EN-02320
BATTERYMAIN RELAYSBF-5
B47 1 2 3 5 4 6
E
E
B100F2
14LHD
RHD
LHD
RHD
B100
F2
F60
E3
20
3
RHD
RHD6
72
3
33
26
25
ECMB134
: LHD: LHD
B21: RHD: RHD
1
4 2
3
B262
FRONT OXYGEN
(A/F) SENSOR
3412
56
123
4
56
78
9
1011 12
1314 15 16
B21
F60
B47
B262
B134
F2
LHD LHD
1234
56 7
82 1
94 310
24 22 23 25 11 12 13 14 15
26 27
2816 17
18 19 20 21
33 34 29
32 30 31
1234 5678910 11 12 13 14 15 16 17 18 19 20
: LHDE2: RHD