Page 1348 of 2870

EN(H4SO)-250
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Start the engine, and warm-up the engine.
2) Turn the ignition switch to OFF.
3) Disconnect the connector from TCM.
4) Turn the ignition switch to ON.
5) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground (
−):Is the voltage less than 3 V? Go to step 2.Repair battery
short circuit in har-
ness between
ECM and TCM
connector. After
repair, replace the
ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>
2 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 15 (+) — Chassis ground (
−):Is the voltage more than 10 V
by shaking the ECM harness
and connector?Repair the battery
short circuit in har-
ness between
ECM and TCM
connector. After
repair, replace the
ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>Contact the SUB-
ARU dealer.
N
OTE:
Inspection by DTM
is required, because
probable cause is
deterioration of mul-
tiple parts.
Page 1350 of 2870

EN(H4SO)-252
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 1 (+) — Chassis ground (
−):Is the voltage more than 4.5 V? Go to step 2.Go to step 4.
2 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B136) No. 1 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and TCM
connector.Go to step 3.
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>
4 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 and ECM connector.
Connector & terminal
(B136) No. 1 — (B56) No. 5:Is the resistance less than 1
Ω?Go to step 5.Repair the open
circuit in harness
between ECM and
TCM connector.
5 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B136) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 6.Repair ground
short circuit in har-
ness between
ECM and TCM
connector.
6 CHECK POOR CONTACT.
Check poor contact in TCM connector.Is there poor contact in TCM
connector?Repair poor con-
tact in TCM con-
nector.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
Page 1352 of 2870

EN(H4SO)-254
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 18 (+) — Chassis ground (
−):Is the voltage more than 4.5 V? Go to step 2.Go to step 4.
2 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM and chas-
sis ground.
Connector & terminal
(B136) No. 18 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and TCM
connector.Go to step 3.
3 CHECK POOR CONTACT.
Check poor contact in ECM connector. Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>
4 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 and ECM connector.
Connector & terminal
(B136) No. 18 — (B56) No. 14:Is the resistance less than 1
Ω?Go to step 5.Repair the open
circuit in harness
between ECM and
TCM connector.
5 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B136) No. 18 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 6.Repair ground
short circuit in har-
ness between
ECM and TCM
connector.
6 CHECK POOR CONTACT.
Check poor contact in TCM connector. Is there poor contact in TCM
connector?Repair poor con-
tact in TCM con-
nector.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
Page 1367 of 2870

FU(H4DOTC)-12
FUEL INJECTION (FUEL SYSTEM)
General Description
C: CAUTION
Wear working clothing, including a cap, protec-
tive goggles, and protective shoes during opera-
tion.
Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
Keep the disassembled parts in order and pro-
tect them from dust or dirt.
Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly, and replacement. Be careful not to burn yourself, because each
part on the vehicle is hot after running.
Be sure to tighten fasteners including bolts and
nuts to the specified torque.
Place shop jacks or rigid racks at the specified
points.
Before disconnecting electrical connectors of
sensors or units, be sure to disconnect the ground
cable from battery.
Place “NO FIRE” signs near the working area.
Be careful not to spill fuel on the floor.
D: PREPARATION TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
24082AA230
(Newly adopted tool)CARTRIDGE Troubleshooting for electrical system.
22771AA030 SUBARU SELECT
MONITOR KITTroubleshooting for electrical systems.
English: 22771AA030 (Without printer)
German: 22771AA070 (Without printer)
French: 22771AA080 (Without printer)
Spanish: 22771AA090 (Without printer)
ST24082AA230
ST22771AA030
Page 1384 of 2870
FU(H4DOTC)-29
FUEL INJECTION (FUEL SYSTEM)
Engine Coolant Temperature Sensor
4. Engine Coolant Temperature
Sensor
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the generator.
REMOVAL, Generator.>
3) Drain the engine coolant.
COOLANT, REPLACEMENT, Engine Coolant.>
4) Disconnect the connector from engine coolant
temperature sensor.
5) Remove the engine coolant temperature sensor.
B: INSTALLATION
Install in the reverse order of removal.
Tightening torque:
18 N
⋅m (1.8 kgf-m, 13.3 ft-lb)
FU-00009
FU-00055
Page 1391 of 2870
FU(H4DOTC)-36
FUEL INJECTION (FUEL SYSTEM)
Manifold Absolute Pressure Sensor
11.Manifold Absolute Pressure
Sensor
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the idle air control solenoid valve.
to FU(H4DOTC)-37, REMOVAL, Idle Air Control
Solenoid Valve.>
3) Disconnect the connectors from manifold abso-
lute pressure sensor.
4) Remove the manifold absolute pressure sensor
from throttle body.
B: INSTALLATION
Install in the reverse order of removal.
NOTE:
Replace the O-rings for manifold absolute pressure
sensor with new ones.
Tightening torque:
1.6 N
⋅m (0.16 kgf-m, 1.2 ft-lb)
FU-00009
FU-00068
Page 1392 of 2870
FU(H4DOTC)-37
FUEL INJECTION (FUEL SYSTEM)
Idle Air Control Solenoid Valve
12.Idle Air Control Solenoid
Valve
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Disconnect the connector from idle air control
solenoid valve.
3) Remove the idle air control solenoid valve from
throttle body.
4) Remove the gasket from throttle body.
B: INSTALLATION
Install in the reverse order of removal.
NOTE:
Replace the gasket with a new one.
Tightening torque:
2.8 N
⋅m (0.29 kgf-m, 2.1 ft-lb)
FU-00009
FU-00070
FU-00071
FU-00072
FU-00071
Page 1422 of 2870
FU(H4DOTC)-67
FUEL INJECTION (FUEL SYSTEM)
Fuel Filter
30.Fuel Filter
A: REMOVAL
WARNING:
Place “NO FIRE” signs near working area.
Be careful not to spill fuel on floor.
1) Release the fuel pressure.
FU(H4DOTC)-54, RELEASING OF FUEL PRES-
SURE, OPERATION, Fuel.>
2) Disconnect the fuel delivery hoses from fuel fil-
ter.
3) Remove the filter from holder.
B: INSTALLATION
CAUTION:
If fuel hoses are damaged at connecting por-
tions, replace them with new ones.
If clamps are badly damaged, replace them
with new ones.
1) Install in the reverse order of removal.
2) Tighten the hose clamp screws.
Tightening torque:
1.25 N
⋅m (0.13 kgf-m, 0.94 ft-lb)
C: INSPECTION
1) Check the inside of fuel filter for dirt and water
sediment.
2) If it is clogged, or if replacement interval has
been reached, replace it.
3) If water is found in it, shake and expel the water
from inlet port.
FU-00118
FU-00118