EN(H6DO)(diag)-5
General Description
ENGINE (DIAGNOSTICS)
3. General Description
A: CAUTION
1) Airbag system wiring harness is routed near the
ECM, main relay and fuel pump relay.
CAUTION:
•All airbag system wiring harnesses and con-
nectors are colored yellow. Do not use electri-
cal test equipment on these circuits.
•Be careful not to damage the airbag system
wiring harness when servicing the ECM, TCM,
main relay and fuel pump relay.
2) Never connect the battery in reverse polarity.
•The ECM will be destroyed instantly.
•The fuel injector and other parts will be dam-
aged.
3) Do not disconnect the battery terminals while the
engine is running.
A large counter electromotive force will be generat-
ed in the generator, and this voltage may damage
electronic parts such as ECM etc.
4) Before disconnecting the connectors of each
sensor and ECM, be sure to turn the ignition switch
to OFF. Perform the clear memory mode after con-
necting the connectors.
5) Poor contact has been identified as a primary
cause of this problem. Measure the voltage or re-
sistance of individual sensor or all electrical control
modules using a tapered pin with a diameter of less
than 0.64 mm (0.025 in). Do not insert the pin more
than 5 mm (0.20 in) into the part.
6) Remove the ECM from the located position after
disconnecting two cables on battery.
Otherwise, the ECM may be damaged.
CAUTION:
When replacing the ECM, be careful not to use
the wrong spec. ECM to avoid any damage on
the fuel injection system.
7) Connectors of each sensor in the engine com-
partment and the harness connectors on the en-
gine side and body side are all designed to be
waterproof. Even if the connectors are waterproof,
take care not to allow water to get into them when
washing the vehicle, or when servicing the vehicle
in rainy weather.
8) Use ECM mounting stud bolts as the grounding
point to chassis when measuring voltage and resis-
tance in the passenger compartment.
9) Use the engine ground terminal or engine as-
sembly as the grounding point to chassis when
measuring the voltage and resistance in engine
compartment.
10) Every MFI-related part is a precision part. Do
not drop them.
11) Observe the following cautions when installing
a radio in MFI equipped models.
CAUTION:
•The antenna must be kept as far apart as pos-
sible from control unit. (The ECM is located un-
der the steering column, inside of the
instrument panel lower trim panel.)
•The antenna feeder must be placed as far apart
as possible from the ECM and MFI harness.
•Carefully adjust the antenna for correct
matching.
•When mounting a large power type radio, pay
special attention to the three items mentioned
above.
•Incorrect installation of the radio may affect
the operation of ECM.
12) Release the pressure in the fuel system before
disconnecting the fuel hose. If engine starts during
this operation, run it until it stops.
13) For the model with ABS, the ABS warning light
may illuminate when performing driving test with
jacked-up or lifted-up condition, but this is not a
system malfunction. The reason for this is the
speed difference between the front and rear
wheels. After diagnosis of engine control system,
perform the ABS memory clear procedure of self-
diagnosis function.
B: INSPECTION
Before performing diagnostics, check the following
item which might affect engine problems.
1. BATTERY
1) Measure the battery voltage and specific gravity
of electrolyte.
Standard voltage: 12 V
Specific gravity: Above 1.260
2) Check the condition of the main and other fuses,
and harnesses and connectors. Also check for
proper grounding.
2. ENGINE GROUND
Make sure the engine ground terminal is properly
connected to engine.
EN-02473
EN(H6DO)(diag)-9
Electrical Component Location
ENGINE (DIAGNOSTICS)
•Sensor
(1) Mass air flow and intake air tem-
perature sensor
(3) Engine coolant temperature sen-
sor
(6) Camshaft position sensor
(7) Crankshaft position sensor
(2) Manifold absolute pressure sensor (4) Electronic throttle control (8) Oil temperature sensor
(5) Knock sensor
EN-03684
(6)(6) (8)
(3)(2)
(7)
(1)
(4) (5)(5)
EN(H6DO)(diag)-18
Engine Control Module (ECM) I/O Signal
ENGINE (DIAGNOSTICS)
Manifold absolute pressure sen-
sorB134 6 3.5 — 4.8 1.1 — 1.9 —
Air flow sensor
Signal B135 26 0.74 0.3 — 4.5 —
Shield B135 35 0 0 —
Ground B135 34 0 0 —
Intake air temperature sensor B135 18 3.15 — 3.33 3.15 — 3.33Intake air tempera-
ture 25°C (75°F)
Fr o nt ox yg e n ( A / F)
sensor RH
Signal (+) B135 9 2.8 — 3.2 2.8 — 3.2 —
Signal (–) B135 8 2.4 — 2.7 2.4 — 2.7 —
Shield B135 1 0 0 —
Fr o nt ox yg e n ( A / F)
sensor heater RH
Signal 1 B136 3 12 — 14 — Waveform
Signal 2 B136 2 12 — 14 — Waveform
Fr o nt ox yg e n ( A / F)
sensor LH
Signal (+) B135 11 2.8 — 3.2 2.8 — 3.2 —
Signal (–) B135 10 2.4 — 2.7 2.4 — 2.7 —
Shield B135 1 0 0 —
Fr o nt ox yg e n ( A / F)
sensor heater LH
Signal 1 B135 7 12 — 14 — Waveform
Signal 2 B135 6 12 — 14 — Waveform
Rear oxygen sen-
sor RH
Signal B135 4 0 0 — 0.9 —
Shield B135 1 0 0 —
Rear oxygen sensor heater RH
signalB136 4 12 — 14 — Waveform
Rear oxygen sen-
sor LH
Signal B135 15 0 0 — 0.9 —
Shield B135 1 0 0 —
Rear oxygen sensor heater LH
signalB136 5 12 — 14 — Waveform
Immobilizer communication 1 B136 26 10 10 —
Immobilizer communication 2 B136 34 10 10 —
Fuel pump control
unit
Diagnosis
signalB135 33 10 — 13 13 — 14 —
Control B136 12 0 0 or 5 —
Brake switch 1 B135 20
When brake pedal is
depressed: 0
When brake pedal is
released: 10 — 13
When brake pedal is
depressed: 0
When brake pedal is
released: 13 — 14
—
Brake switch 2 B135 28
When brake pedal is
depressed: 10 — 13
When brake pedal is
released: 0
When brake pedal is
depressed: 13 — 14
When brake pedal is
released: 0
—
Cruise control command switch B135 24
When operating
nothing: 3.5 — 4.5
When operating
RES/ACC: 2.5 — 3.5
When operating SET/
COAST: 0.5 — 1.5
When operating
CANCEL: 0 — 0.5
When operating
nothing: 3.5 — 4.5
When operating
RES/ACC: 2.5 — 3.5
When operating SET/
COAST: 0.5 — 1.5
When operating
CANCEL: 0 — 0.5
—
Cruise control main switch B135 12ON: 0
OFF: 5
ON: 0
OFF: 5—
Oil flow control sole-
noid valve RH
Signal (+) B137 17 0 0.6 —
Signal (–) B137 16 0 0 —
Oil flow control sole-
noid valve LH
Signal (+) B137 15 0 0.6 —
Signal (–) B137 14 0 0 —
DescriptionConnector
No.
Te r m i n a l
No.
Signal (V)
ReferenceIgnition SW ON
(engine OFF)
Engine ON
(idling)
EN(H6DO)(diag)-23
General Scan Tool
ENGINE (DIAGNOSTICS)
2. MODE $01 (CURRENT POWERTRAIN DIAGNOSTIC DATA)
Refer to data denoting the current operating condition of analog input/output, digital input/output or the pow-
ertrain system.
A list of the support data and PID (Parameter Identification) codes are shown in the following table.
NOTE:
Refer to general scan tool manufacturer’s operation manual to access generic OBD-II PIDs (MODE $01).
PID Data Unit of measure
01 Number of emission-related powertrain DTC and malfunction indicator light status ON/OFF
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim (Bank 1)%
07 Long term fuel trim (Bank 1)%
08 Short term fuel trim (Bank 2)%
09 Long term fuel trim (Bank 2)%
0B Intake manifold absolute pressure kPa
0C Engine revolutionrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
0F Intake air temperature°C
10 Air flow rate of manifold absolute pressure sensor g/sec
11 Throttle valve opening angle%
13 Check whether oxygen sensor is installed. —
15 Oxygen sensor output voltage (Bank 1 Sensor 2) V
15 Oxygen sensor compensation (Bank 1 Sensor 2) %
19 Oxygen sensor output voltage (Bank 2 Sensor 2) V
1C On-board diagnostic system—
24 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor (bank 1) V and %
28 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor (bank 2) V and %
34 A/F sensor lambda value (Bank 1 Sensor 1) —
34 A/F sensor current value (Bank 1 Sensor 1) mA
38 A/F sensor lambda value (Bank 2 Sensor 1) —
38 A/F sensor current value (Bank 2 Sensor 1) mA
EN(H6DO)(diag)-24
General Scan Tool
ENGINE (DIAGNOSTICS)
3. MODE $02 (POWERTRAIN FREEZE FRAME DATA)
Refer to data denoting the operating condition when trouble is detected by on-board diagnosis system.
A list of the support data and PID (Parameter Identification) codes are shown in the following table.
NOTE:
Refer to general scan tool manufacturer’s operation manual to access freeze frame data (MODE $02).
4. MODE $03 (EMISSION-RELATED POWERTRAIN DTC)
Refer to “List of Diagnostic Trouble Code (DTC)” for information about data denoting emission-related pow-
ertrain DTC.
5. MODE $04 (CLEAR/RESET EMISSION-RELATED DIAGNOSTIC INFORMATION)
Refer to the mode used to clear or reset emission-related diagnostic information (OBD-II trouble diagnostic
information).
NOTE:
Refer to general scan tool manufacturer's operation manual to clear or reset emission-related diagnostic in-
formation (MODE $04).
PID Data Unit of measure
02 DTC that caused CARB required freeze frame data storage —
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim (Bank 1)%
07 Long term fuel trim (Bank 1)%
08 Short term fuel trim (Bank 2)%
09 Long term fuel trim (Bank 2)%
0B Intake manifold absolute pressure kPa
0C Engine speedrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
0F Intake air temperature°C
10 Air flow rate of manifold absolute pressure sensor g/sec
11 Throttle valve opening angle%
15 Oxygen sensor output voltage (Bank 1 Sensor 2) V
15 Oxygen sensor compensation (Bank 1 Sensor 2) %
16 Oxygen sensor output voltage (Bank 2 Sensor 2) V
16 Oxygen sensor compensation (Bank 2 Sensor 2) %
1C On-board diagnostic system—
EN(H6DO)(diag)-27
Subaru Select Monitor
ENGINE (DIAGNOSTICS)
4. READ CURRENT DATA FOR ENGINE (NORMAL MODE)
1) On the «Main Menu» display screen, select the {Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen, select the {Engine} and press the [YES] key.
3) Press the [YES] key after the information of engine type has been displayed.
4) On the «Engine Diagnosis» display screen, select the {Current Data Display/Save}, and then press the
[YES] key.
5) On the «Data Display Menu» screen, select the {Data Display} and press the [YES] key.
6) Using the scroll key, scroll the display screen up or down until the desired data is shown.
•A list of the support data is shown in the following table.
Description Display Unit of measure Note (at idling)
Engine load Engine load % 3.5%
Engine coolant temperature signal Coolant Temp. °C or °F≥ 75°C or 167°F (After
engine is warmed-up.)
A/F compensation 1 A/F Compensation 1 % 3.1%
A/F learning 1 A/F learning 1 % 0.0%
A/F compensation 2 A/F Compensation 2 % 4.7%
A/F learning 2 A/F learning 2 % 0.0%
Intake manifold absolute pressure Mani. Absolute PressuremmHg, kPa,
inHg or psig
200 — 300 mmHg, 26.7 —
40 kPa, 7.8 — 11.8 inHg or
3.8 — 5.8 psig
Engine speed signal Engine speed rpm 600 — 800 rpm
Meter vehicle speed signal Meter vehicle speed km/h or MPH 0 km/h or 0 MPH
Ignition timing signal Ignition timing deg 13 — 15 deg
Intake air temperature signal Intake air temperature °C or °F (Ambient air temperature)
Amount of intake air Mass Air Flow g/s or lb/m 3.8 g/s or 0.5 lb/m
Throttle opening angle signal Throttle valve angle % 1.2 — 1.6%
Fr o nt ox yg e n se n so r vo lt a g e val ue 1Fr o n t oxy ge n s en s or vol t ag e
value 1V0.035 V
Fr o nt ox yg e n se n so r vo lt a g e val ue 2Fr o n t oxy ge n s en s or vol t ag e
value 2V0.020 V
Battery voltage Battery Voltage V 12 — 14 V
Mass air flow voltage Mass air flow voltage V 1.1 — 1.2 V
Injection 1 pulse width Injection 1 pulse width ms 2.82 ms
Injection 2 pulse width Injection 2 pulse width ms 2.82 ms
Knock sensor compensation Knock correction deg 0 deg
Atmospheric pressure signal Atmospheric pressuremmHg, kPa,
inHg or psig(Atmospheric pressure)
Intake manifold relative pressureIntake manifold relative pres-
sure
mmHg, kPa,
inHg or psig
(Intake manifold absolute
pressure — atmospheric
pressure)
Acceleration opening angle signal Acceleration opening angle % 0%
Radiator fan output Radiator fan output % 0%
Purge control solenoid valve duty ratio CPC Duty % 0 — 3%
Generator duty ALT duty % 0%
Fuel pump duty Fuel pump duty % 33%
Va r i a b l e va l v e t i m i n g a d v a n c e a n g l e a m o u n t R V V T a d va n c e a n g l e a m o u n t R d e g 0 d e g
Va r i a b l e va l v e t i m i n g a d v a n c e a n g l e a m o u n t L V V T a d va n c e a n g l e a m o u n t L d e g 0 d e g
Oil flow control solenoid valve duty R OCV duty R % 9.4%
Oil flow control solenoid valve duty L OCV duty L % 9.4%
Oil flow control solenoid valve current R OCV current R mA 64 mA
Oil flow control solenoid valve current L OCV current L mA 64 mA
Fr o nt ox yg e n ( A / F) s en so r cu r r en t va l ue 1 A / F s en s or cu r r e nt va l ue 1 mA 0 . 0 m A
Fr o nt ox yg e n ( A / F) s en so r cu r r en t va l ue 2 A / F s en s or cu r r e nt va l ue 2 mA 0 . 0 m A
Fr o nt ox yg e n ( A / F) s en so r r es is t an ce val ue 1 A / F s en s or r e si st a nc e val u e 1Ω31 Ω
EN(H6DO)(diag)-30
Subaru Select Monitor
ENGINE (DIAGNOSTICS)
NOTE:
For detailed operation procedure, refer to the “SUBARU SELECT MONITOR OPERATION MANUAL”.
Intake manifold absolute pressure Mani. Absolute Pressure mmHg, kPa, inHg or psig
Engine speed Engine speed rpm
Ve h i c l e s p e e d Ve h i c l e s p e e d k m / h o r M P H
Ignition timing #1 Ignition timing adv.#1 °
Intake air temperature Intake Air Temp. °C or °F
Amount of intake air Mass Air Flow g/s or lb/m
Throttle valve angle Throttle Opening Angle %
Oxygen sensor #12 Oxygen sensor #12 V
A/F compensation #12 Short term fuel trim #12 %
Oxygen sensor #22 Oxygen sensor #22 %
A/F compensation #22 Short term fuel trim #22 %
OBD system OBD System —
Oxygen sensor #11 Oxygen sensor #11 support
Oxygen sensor #12 Oxygen sensor #12 support
Oxygen sensor #21 Oxygen sensor #21 support
Oxygen sensor #22 Oxygen sensor #22 support
A/F sensor #11 A/F sensor #11 —
A/F sensor #11 A/F sensor #11 V
A/F sensor #21 A/F sensor #21 —
A/F sensor #21 A/F sensor #21 V
A/F sensor #11 A/F sensor #11 —
A/F sensor #11 A/F sensor #11 mA
A/F sensor #21 A/F sensor #21 —
A/F sensor #21 A/F sensor #21 mA
Description Display Unit of measure
EN(H6DO)(diag)-31
Subaru Select Monitor
ENGINE (DIAGNOSTICS)
6. READ FREEZE FRAME DATA FOR ENGINE (OBD MODE)
1) On the «Main Menu» display screen, select the {Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen, select the {Engine} and press the [YES] key.
3) Press the [YES] key after the information of engine type has been displayed.
4) On the «Engine Diagnosis» display screen, select the {OBD System} and press the [YES] key.
5) On the «OBD Menu» display screen, select the {Freeze Frame Data} and press the [YES] key.
•A list of the support data is shown in the following table.
NOTE:
For detailed operation procedure, refer to the “SUBARU SELECT MONITOR OPERATION MANUAL”.
Description Display Unit of measure
DTC of freeze frame data Freeze frame data DTC
Air fuel ratio control system for bank 1 Fuel system for Bank1 —
Air fuel ratio control system for bank 2 Fuel system for Bank2 —
Engine load data Engine Load %
Engine coolant temperature signal Coolant Temp. °C or °F
Short term fuel trim by front oxygen (A/F) sensor (Bank 1) Short term fuel trim B1 %
Long term fuel trim by front oxygen (A/F) sensor (Bank 1) Long term fuel trim B1 %
Short term fuel trim by front oxygen (A/F) sensor (Bank 2) Short term fuel trim B2 %
Long term fuel trim by front oxygen (A/F) sensor (Bank 2) Long term fuel trim B2 %
Intake manifold absolute pressure signal Mani. Absolute Pressure mmHg, kPa, inHg or psig
Engine speed signal Engine Speed rpm
Ve h i c l e s p e e d s i g n a l Ve h i c l e S p e e d k m / h o r M P H
Ignition timing #1 Ignition timing adv. #1 °
Intake air temperature Intake Air Temp. °C
Amount of intake air Mass Air Flow g/s
Throttle valve angle Throttle Opening Angle %
Oxygen sensor #12 Oxygen sensor #12 V
A/F compensation #12 Short term fuel trim #12 %
Oxygen sensor #22 Oxygen sensor #22 V
A/F compensation #12 Short term fuel trim #22 %
Oxygen sensor #11 Oxygen sensor #11 support
Oxygen sensor #12 Oxygen sensor #12 support
Oxygen sensor #21 Oxygen sensor #21 support
Oxygen sensor #22 Oxygen sensor #22 support