
EN(H4DOTC)-195
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK SPEEDOMETER AND TACHOME-
TER OPERATION IN COMBINATION
METER.Does the speedometer and
tachometer operate normally?Go to step 2.Repair or replace
the combination
meter.
Meter System.>
2 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.(engine OFF)
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
−):Is the voltage less than 0.12
V?Go to step 4.Go to step 3.
3 CHECK INPUT SIGNAL FOR ECM (WITH
SUBARU SELECT MONITOR).
Read the data of fuel level sensor signal using
Subaru Select Monitor.
N
OTE:
Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”.
shaking the harness and con-
nector of ECM while monitor-
ing the value with Subaru
Select Monitor?Repair the poor
contact in ECM
connector.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.A tempo-
rary poor contact
of the connector
may be the cause.
N
OTE:
In this case repair
the following:
Poor contact in
combination meter
connector
Poor contact in
ECM connector
Poor contact in
coupling connector
4 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
−):Is the voltage more than 0.12
V?Go to step 5.Go to step 6.
5 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from connector
(i10), (i11) and ECM connector.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B136) No. 20 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 7.Repair the ground
short in harness
between ECM and
combination meter
connector.
6 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
Measure the resistance between ECM and
combination meter connector.
Connector & terminal
(B136) No. 20 — (i11) No. 1:Is the resistance less than 10
Ω?Repair or replace
the combination
meter.
Meter System.>Repair open circuit
between ECM and
combination meter
connector.
N
OTE:
In this case repair
the following:
Poor contact in
coupling connector

EN(H4DOTC)-196
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FUEL TANK CORD.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from fuel sub
level sensor.
3) Measure the resistance between fuel sub
level sensor and chassis ground.
Connector & terminal
(R59) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 8.Repair ground
short circuit in fuel
tank cord.
8 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel pump
assembly.
2) Measure the resistance between fuel pump
assembly and chassis ground.
Connector & terminal
(R59) No. 2 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 9.Repair ground
short circuit in fuel
tank cord.
9 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly.
2) Measure the resistance between fuel level
sensor and terminals with its float set to the full
position.
Te r m i n a l s
No. 3 — No. 5:Is the resistance 0.5 — 2.5 Ω? Go to step 10.Replace the fuel
level sensor.
10 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor.
2) Measure the resistance between fuel sub
level sensor and terminals with its float set to
the full position.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 0.5 — 2.5 Ω? Repair poor con-
tact in harness
between ECM and
combination meter
connector.Replace the fuel
sub level sensor. Step Check Yes No

EN(H4DOTC)-198
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK SPEEDOMETER AND TACHOME-
TER OPERATION IN COMBINATION
METER.Does the speedometer and
tachometer operate normally?Go to step 2.Repair or replace
the combination
meter.
Meter System.>
2 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.(engine OFF)
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
−):Is the voltage more than 4.75
V?Go to step 3.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.A tempo-
rary poor contact
of the connector
may be the cause.
N
OTE:
In this case repair
the following:
Poor contact in
fuel pump connec-
tor
Poor contact in
coupling connector
3 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the combination meter connec-
tor (i11) and ECM connector.
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
−):Is the voltage more than 4.75
V?Go to step 4.Repair battery
short circuit
between ECM and
combination meter
connector.
4 CHECK HARNESS BETWEEN ECM AND
FUEL TANK CORD.
1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Measure the resistance between ECM and
fuel tank cord.
Connector & terminal
(B136) No. 20 — (R15) No. 2:Is the resistance less than 5
Ω?Go to step 5.Repair open circuit
between ECM and
fuel tank cord.
5 CHECK HARNESS BETWEEN FUEL TANK
CORD AND CHASSIS GROUND.
Measure the resistance between fuel tank cord
and chassis ground.
Connector & terminal
(R15) No. 3 — Chassis ground:Is the resistance less than 5
Ω?Go to step 6.Repair open circuit
between fuel tank
cord and chassis
ground.
N
OTE:
In this case repair
the following:
Poor contact in
coupling connector
6 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel level
sensor.
2) Measure the resistance between fuel level
sensor and coupler connector.
Connector & terminal
(R57) No. 3 — (R58) No. 5:Is the resistance less than 10
Ω?Go to step 7.Repair open circuit
between coupling
connector and fuel
level sensor.

EN(H4DOTC)-199
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK FUEL TANK CORD.
1) Disconnect the connector from fuel sub
level sensor.
2) Measure the resistance between fuel level
sensor and fuel sub level sensor.
Connector & terminal
(R58) No. 3 — (R59) No. 2:Is the resistance less than 10
Ω?Go to step 8.Repair open circuit
between fuel level
sensor and fuel
sub level sensor.
8 CHECK FUEL TANK CORD.
Measure the resistance between fuel sub level
sensor and coupler connector.
Connector & terminal
(R57) No. 2 — (R59) No. 1:Is the resistance less than 10
Ω?Go to step 9.Repair open circuit
between coupling
connector and fuel
sub level sensor.
9 CHECK FUEL LEVEL SENSOR.
1) Remove the fuel pump assembly.
2) While moving the fuel level sensor float up
and down, measure resistance between fuel
level sensor terminals.
Te r m i n a l s
No. 3 — No. 5:Is the resistance more than 53
Ω?Replace the fuel
level sensor.
64, Fuel Level
Sensor.>Go to step 10.
10 CHECK FUEL SUB LEVEL SENSOR.
1) Remove the fuel sub level sensor.
2) While moving the fuel sub level sensor float
up and down, measure resistance between
fuel sub level sensor terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance more than 45
Ω?Replace the fuel
sub level sensor.
Fuel Sub Level
Sensor.>Replace the com-
bination meter.
Meter Assembly.> Step Check Yes No

EN(H4DOTC)-206
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK TRANSMISSION TYPE.Is the transmission type AT? Go to step 2.Go to step 4.
2 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
TCM.
3) Measure the resistance of harness
between TCM connector and chassis ground.
Connector & terminal
(B56) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in har-
ness between
ECM and TCM
connector.
3 CHECK POOR CONTACT.
Check poor contact in TCM connector.Is there poor contact in TCM
connector?Repair poor con-
tact in TCM con-
nector.Contact the SUB-
ARU dealer.
4 CHECK HARNESS BETWEEN VEHICLE
SPEED SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from vehicle
speed sensor ECM.
3) Measure the resistance of harness
between vehicle speed sensor connector and
chassis ground.
Connector & terminal
(B17) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 5.Repair ground
short circuit in har-
ness between
vehicle speed sen-
sor and ECM con-
nector.
5 CHECK POOR CONTACT.
Check poor contact in vehicle speed sensor
connector.Is there poor contact in vehicle
speed sensor connector?Repair poor con-
tact in vehicle
speed sensor con-
nector.Replace the vehi-
cle speed sensor.
Sensor.>

EN(H4DOTC)-212
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Inspect the rele-
vant DTC using
“List of Diagnostic
Trouble Code
(DTC)”.
List of Diagnostic
Trouble Code
(DTC).>
N
OTE:
In this case, it is
not necessary to
inspect DTC
P0507.Go to step 2.
2 CHECK THROTTLE CABLE.Does the throttle cable have
play for adjustment?Go to step 3.Adjust throttle
cable.
INSTALLATION,
Accelerator Con-
trol Cable.>
3 CHECK AIR INTAKE SYSTEM.
1) Turn the ignition switch to ON.
2) Start and idle the engine.
3) Check the following items:
Loose installation of intake manifold, idle air
control solenoid valve and throttle body
Cracks of intake manifold gasket, idle air
control solenoid valve gasket and throttle body
gasket
Disconnections of vacuum hosesIs there any fault in air intake
system?Repair air suction
and leaks.Replace the idle
air control solenoid
valve.
Idle Air Control
Solenoid Valve.>

EN(H4DOTC)-214
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 between ECM and
chassis ground.
Connector & terminal
(B134) No. 27 (+) — Chassis ground (
−):Is the voltage more than 3 V? Repair the poor
contact in ECM
connector.Go to step 2.
2 CHECK POWER SUPPLY TO IDLE AIR CON-
TROL SOLENOID VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from idle air con-
trol solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between idle air con-
trol solenoid valve and engine ground.
Connector & terminal
(E7) No. 2 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 3.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
idle air control
solenoid valve and
main relay connec-
tor
Poor contact in
coupling connector
3 CHECK HARNESS BETWEEN ECM AND
IDLE AIR CONTROL SOLENOID VALVE
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM and idle air control solenoid
valve connector.
Connector & terminal
(B134) No. 27 — (E7) No. 1:Is the resistance less than 1
Ω?Go to step 4.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ECM and idle air
control solenoid
valve connector
Poor contact in
coupling connector
4 CHECK HARNESS BETWEEN ECM AND
IDLE AIR CONTROL SOLENOID VALVE
CONNECTOR.
Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B134) No. 10 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 5.Repair ground
short circuit in har-
ness between
ECM and idle air
control solenoid
valve connector.
5 CHECK GROUND CIRCUIT OF IDLE AIR
CONTROL SOLENOID VALVE.
Measure the resistance of harness between
idle air control solenoid valve connector and
engine ground.
Connector & terminal
(E7) No. 3 — Engine ground:Is the resistance less than 5
Ω?Go to step 6.Repair open circuit
in harness
between idle air
control solenoid
valve connector
and engine ground
cable.
6 CHECK POOR CONTACT.
Check poor contact in ECM and idle air control
solenoid valve connectors. Is there poor contact in ECM
and idle air control solenoid
valve connectors?Repair poor con-
tact in ECM and
idle air control
solenoid valve
connectors.Replace the idle
air control solenoid
valve.
Idle Air Control
Solenoid Valve.>

EN(H4DOTC)-216
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK THROTTLE CABLE.Does the throttle cable have
play for adjustment?Go to step 2.Adjust throttle
cable.
Accelerator Con-
trol Cable.>
2 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 27 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 3.Go to step 4.
3 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from idle air con-
trol solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 27 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and idle air
control solenoid
valve connec-
tor.After repair,
replace the ECM.
Engine Control
Module (ECM).>Replace the idle
air control solenoid
valve and ECM.
Idle Air Control
Solenoid Valve.>
Engine Control
Module (ECM).>
4 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B134) No. 27 (+) — Chassis ground (
−):Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with voltage
meter?Repair battery
short circuit in har-
ness between
ECM and idle air
control solenoid
valve connec-
tor.After repair,
replace the ECM.
Engine Control
Module (ECM).>Contact the SUB-
ARU dealer.
N
OTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.