2004 SUBARU FORESTER sensor

EN(H4SO)-75
ENGINE (DIAGNOSTIC)
List of Diagnostic Trouble Code (DTC)
P0720 AT Vehicle Speed Sensor Circuit
Malfunction nostic Procedure with Diagnostic Trouble Code (DTC).>
P0726 Engine Speed Input Circuit Malfunc-
tion cedure with Diagnostic Trouble Code (DTC).>
P0731 Gear 1 Incorrect Ratio nostic Procedure with Diagnostic Trouble Code (DTC).>
P0732 Gear 2 Incorrect Ratio nostic Procedure with Diagnostic Trouble Code (DTC).>
P0733 Gear 3 Incorrect Ratio nostic Procedure with Diagnostic Trouble Code (DTC).>
P0734 Gear 4 Incorrect Ratio nostic Procedure with Diagnostic Trouble Code (DTC).>
P0741 Torque Converter Clutch Circuit Per-
formance or Stuck Off CIRCUIT PERFORMANCE OR STUCK OFF, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P0743 Torque Converter Clutch Circuit Elec-
trical Procedure with Diagnostic Trouble Code (DTC).>
P0748 Pressure Control Solenoid “A” Elec-
trical nostic Procedure with Diagnostic Trouble Code (DTC).>
P0753 Shift Solenoid “A” Electrical with Diagnostic Trouble Code (DTC).>
P0758 Shift Solenoid “B” Electrical with Diagnostic Trouble Code (DTC).>
P0771 Low clutch timing solenoid nostic Procedure with Diagnostic Trouble Code (DTC).>
P0778 Pressure Control Solenoid “B” Elec-
trical Procedure with Diagnostic Trouble Code (DTC).>
P0785 Shift/Timing Solenoid tic Procedure with Diagnostic Trouble Code (DTC).>
P0851 Neutral Switch Input Circuit Low LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).> or to EN(H4SO)-214, DTC P0851 NEUTRAL SWITCH INPUT CIRCUIT LOW
(MT MODEL), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0852 Neutral Switch Input Circuit High HIGH, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0864 TCM Communication Circuit Range/
Pe r fo r ma nc e RANGE/PERFORMANCE, Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>
P0865 TCM Communication Circuit Low LOW, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P0866 TCM Communication Circuit Low HIGH, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P1110 Atmospheric Pressure Sensor Circuit
Malfunction (Low Input) SOR CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1111 Atmospheric Pressure Sensor Circuit
Malfunction (High Input) SOR CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
P1134 A/F Sensor Micro-Computer Problem PROBLEM, Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
P1137 O
2 Sensor Circuit (Lambda= 1)
(Bank 1 Sensor 1) (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trouble Code
(DTC).>
P1492 EGR Valve Signal #1 Circuit Malfunc-
tion (Low Input) MALFUNCTION (LOW INPUT), Diagnostic Procedure with Diagnostic Trou-
ble Code (DTC).> DTC Item NOTE

EN(H4SO)-77
ENGINE (DIAGNOSTIC)
List of Diagnostic Trouble Code (DTC)
P1576 EGI Control Module EEPROM tics Procedure with Diagnostic Trouble Code (DTC).>
P1577 IMM Control Module EEPROM tics Procedure with Diagnostic Trouble Code (DTC).>
P1698 Engine Torque Control Cut Signal
Circuit Malfunction (Low Input) SIGNAL CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>
P1699 Engine Torque Control Cut Signal
Circuit Malfunction (High Input) SIGNAL CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>
P1700 Throttle Position Sensor Circuit Mal-
function For AT nostic Procedure with Diagnostic Trouble Code (DTC).>
P1711 Engine Torque Control Signal #1 Cir-
cuit Malfunction NAL #1 CIRCUIT MALFUNCTION, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
P1712 Engine Torque Control Signal #2 Cir-
cuit Malfunction NAL #2 CIRCUIT MALFUNCTION, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).> DTC Item NOTE

EN(H4SO)-78
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
19.Diagnostic Procedure with Diagnostic Trouble Code (DTC)
A: DTC P0030 HO2S HEATER CONTROL CIRCUIT (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 tion Mode.>.
WIRING DIAGRAM:
EN-02384
B18
3412
56
B47F44
12345678
B136B135
1234
B21
123
4
56
78
9
1011 12
1314 15 16
SBF-5
EE
B47
B18
6
4
5
3
2
1
B23 C13
C22C6 C17
C16
C5
8
B:
C:B135
B136
B21
E2 ECMBATTERY
B61F44
7
FRONT OXYGEN
(A/F) SENSOR MAIN RELAY
567
82 1
94
310
24
22 23251112131415
26 27
281617181920 21
5
2
84
3923 20 211011
221617
24
2512136
261915
14
1
7
18
LHDLHD
RHDRHD
4
3
1 2
B: C:

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, 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
(B136) No. 6 — (B18) No. 3:
(B136) No. 17 — (B18) No. 3:Is the resistance less than 1
Ω?Go to step 2.Repair 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
(B136) No. 13 — (B18) No. 1:
(B136) No. 22 — (B18) No. 2:Is the resistance less than 1
Ω?Go to step 3.Repair open circuit
in harness
between ECM and
front oxygen (A/F)
sensor connector.
3 CHECK HARNESS BETWEEN MAIN RELAY
AND FRONT OXYGEN (A/F) SENSOR CON-
NECTOR.
Measure the resistance of harness between
main relay and front oxygen (A/F) sensor con-
nector.
Connector & terminal
(B47) No. 4 — (B18) No. 4:Is the resistance less than 1
Ω?Go to step 4.Repair 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. 3 — No. 4:Is the resistance less than 5
Ω?Go to step 5.Replace the front
oxygen (A/F) sen-
sor. FU(H4SO)-40,
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 poor con-
tact in ECM or
front oxygen (A/F)
sensor connector.Replace the front
oxygen (A/F) sen-
sor. FU(H4SO)-40,
Front Oxygen (A/
F) Sensor.>

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 recognition
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-02384
B18
3412
56
B47F44
12345678
B136B135
1234
B21
123
4
56
78
9
1011 12
1314 15 16
SBF-5
EE
B47
B18
6
4
5
3
2
1
B23 C13
C22C6 C17
C16
C5
8
B:
C:B135
B136
B21
E2 ECMBATTERY
B61F44
7
FRONT OXYGEN
(A/F) SENSOR MAIN RELAY
567
82 1
94
310
24
22 23251112131415
26 27
281617181920 21
5
2
84
3923 20 211011
221617
24
2512136
261915
14
1
7
18
LHDLHD
RHDRHD
4
3
1 2
B: C:

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.

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 oxy-
gen (A/F) sensor connector terminals.
Te r m i n a l s
No. 3 — No. 4:Is the resistance less than 10
Ω?Repair harness
and connector.
N
OTE:
In this case repair
the following:
 Open or ground
short circuit in har-
ness between front
oxygen (A/F)
sensor and ECM
connector
 Poor contact in
front oxygen (A/F)
sensor connector
 Poor contact in
ECM connector.Replace the front
oxygen (A/F) sen-
sor. FU(H4SO)-47,
Fuel.> Step Check Yes No

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 malfunction occurs.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
WIRING DIAGRAM:
EN-02384
B18
3412
56
B47F44
12345678
B136B135
1234
B21
123
4
56
78
9
1011 12
1314 15 16
SBF-5
EE
B47
B18
6
4
5
3
2
1
B23 C13
C22C6 C17
C16
C5
8
B:
C:B135
B136
B21
E2 ECMBATTERY
B61F44
7
FRONT OXYGEN
(A/F) SENSOR MAIN RELAY
567
82 1
94
310
24
22 23251112131415
26 27
281617181920 21
5
2
84
3923 20 211011
221617
24
2512136
261915
14
1
7
18
LHDLHD
RHDRHD
4
3
1 2
B: C: