VDC(diag)-88
General Diagnostic Table
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Vibration or
noise
•When braking
suddenly
•When acceler-
ating suddenly
•While driving
on a slippery
road
Excessive
brake pedal
vibration
•Road surface (uneven)
•Incorrect wiring or piping connections
•VDCCM&H/U
•Brake booster
•Suspension play or fatigue (poor damp-
ing)
Noise from
VDCH/U
•VDCCM&H/U (mount bushing)
•Defective ABS wheel speed sensor or sensor
gap
•Brake pipe
•VDCCM&H/U
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
Noise from
the front side
of vehicle
•VDCCM&H/U (mount bushing)
•Defective ABS wheel speed sensor or sensor
gap
•Master cylinder
•Brake caliper
•Brake pad
•Disc rotor
•Brake pipe
•Brake booster
•Suspension play or fatigue (poor damping)
•Axle and wheels
•Tire specifications, tire wear and air
pressures
Noise inside
passenger
seat
•VDCCM&H/U
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
Noise from
the rear side
of vehicle
•Defective ABS wheel speed sensor or sensor
gap
•Brake caliper
•Brake pad
•Disc rotor
•Parking brake
•Brake pipe
•Suspension play or fatigue (poor damping)
•Axle and wheels
•Tire specifications, tire wear and air
pressures
Engine does not accelerate or
goes into a stall when accelerat-
ing suddenly or driving on a slip-
pery surface.
•VDCCM&H/U
•Defective ABS wheel speed sensor or sensor
gap
•Master cylinder
•Brake caliper
•Parking brake
•Incorrect wiring or piping
•Defective steering angle sensor or
improper neutral position
•Defective yaw rate & G sensor or
improper installation
•Brake pad
•Brake pipe
Symptom Main probable cause Other probable cause
CO(H6DO)-30
Engine Cooling System Trouble in General
COOLING
12.Engine Cooling System Trouble in General
A: INSPECTION
Tr o u b l e P o s s i b l e c a u s e C o r r e c t i v e a c t i o n
Overheating
a. Insufficient engine coolantReplenish engine coolant, inspect for leakage, and
repair it if necessary.
b. De fe c ti ve t he r mo st a t Rep la c e.
c. Malfunction of water pump Replace.
d. Clogged engine coolant passage Clean.
e. Improper ignition timing
Inspect and repair ignition control system.
Procedure.>
f. Clogged or leaking radiator Clean, repair or replace.
g. Improper engine oil in engine coolant Replace engine coolant.
h. Air/fuel mixture ratio too lean
Inspect and repair the fuel injection system.
Procedure.>
i. Excessive back pressure in exhaust system Clean or replace.
j. Insufficient clearance between piston and cylinder Adjust or replace.
k. Slipping clutch Correct or replace.
l. Dragging brake Adjust.
m. Faulty transmission gear oil Replace.
n. Malfunction of radiator fanInspect the radiator fan relay, engine coolant tempera-
ture sensor or fan motor and replace them.
Over-coolinga. Ambient temperature extremely low Partly cover radiator front area.
b. De fe c ti ve t he r mo st a t Rep la c e.
Engine coolant
leaks
a. Loosened or damaged connecting units on hoses Correct or replace.
b. L ea k ag e f r o m wat e r pu mp Rep la c e.
c. Leakage from water pipe Correct or replace.
d. Leakage around cylinder head gasket Retighten cylinder head bolts or replace gasket.
e. Damaged or cracked cylinder head and crankcase Correct or replace.
f. Damaged or cracked ther mostat case Correct or replace.
g. Leakage from radiator Correct or replace.
Strange noise
a. Defective drive belt Replace.
b. De fe c ti ve ra di a t or fan Rep la c e.
c. Defective water pump bearing Replace water pump.
d. Defective water pump mechanical seal Replace water pump.
EN(H6DO)(diag)-6
General Description
ENGINE (DIAGNOSTICS)
C: NOTE
1. GENERAL DESCRIPTION
•The on-board diagnostics (OBD) system detects
and indicates a fault in various inputs and outputs
of the complex electronic control. Malfunction indi-
cator light in the combination meter indicates oc-
currence of a fault or trouble.
•Further, against such a failure or sensors as may
disable the drive, the fail-safe function is provided
to ensure the minimal drivability.
•The OBD system incorporated with the vehicles
within this engine family complies with OBD-II Reg-
ulations. The OBD system monitors the compo-
nents and the system malfunction listed in Engine
Section which affects on emissions.
•When the system decides that a malfunction oc-
curs, malfunction indicator light illuminates. At the
same time of the malfunction indicator light illumi-
nation or blinking, a DTC and a freeze frame en-
gine conditions are stored into on-board computer.
•The OBD system stores freeze frame engine
condition data (engine load, engine coolant tem-
perature, fuel trim, engine speed and vehicle
speed, etc.) into on-board computer when it detects
a malfunction first.
•If the OBD system detects the various malfunc-
tions including the fault of fuel trim or misfire, the
OBD system first stores freeze frame engine condi-
tions about fuel trim or misfire.
•When the malfunction does not occur again for
three consecutive driving cycles, malfunction indi-
cator light is turned off, but DTC remains at on-
board computer.
•When troubleshooting the vehicle which com-
plies with OBD-II Regulations, connect the Subaru
Select Monitor or general scan tool to the vehicle.
2. ENGINE AND EMISSION CONTROL SYS-
TEM
•The Multipoint Fuel Injection (MFI) system is a
system that supplies the optimum air-fuel mixture
to the engine for all the various operating condi-
tions through the use of the latest electronic tech-
nology.
With this system fuel, which is pressurized at a con-
stant pressure, is injected into the intake air pas-
sage of the cylinder head. The injection quantity of
fuel is controlled by an intermittent injection system
where the electro-magnetic injection valve (fuel in-
jector) opens only for a short period of time, de-
pending on the quantity of air required for one cycle
of operation. In actual operation, the injection quan-
tity is determined by the duration of an electric
pulse applied to the fuel injector and this permits
simple, yet highly precise metering of the fuel.
•Further, all the operating conditions of the engine
are converted into electric signals, and this results
in additional features of the system, such as large
improved adaptability, easier addition of compen-
sating element etc.
The MFI system also has the following features:
•Reduced emission of harmful exhaust gases.
•Reduced in fuel consumption.
•Increased engine output.
•Superior acceleration and deceleration.
•Superior startability and warm-up perfor-
mance in cold weather since compensation is
made for coolant and intake air temperature.
EN(H6DO)(diag)-28
Subaru Select Monitor
ENGINE (DIAGNOSTICS)
Fr o nt ox yg e n ( A / F) s en so r r es is t an ce val ue 2 A / F s en s or r e si st a nc e val u e 2Ω31 Ω
Fr o nt ox yg e n ( A / F) s en so r ou t p ut la m bd a 1 A / F s en s or o ut p ut l am bd a 1 — 1 . 00
Fr o nt ox yg e n ( A / F) s en so r ou t p ut la m bd a 2 A / F s en s or o ut p ut l am bd a 2 — 1 . 00
Fuel tank pressure signal Fuel Tank PressuremmHg, kPa,
inHg or psig
+8.8 mmHg, +1.2 kPa,
+0.4 inHg or +0.17 psig
Fuel temperature signal Fuel Temp. °C or °F +28°C or +82°F
A/F compensation 3 A/F Compensation 3 % –0.16%
A/F learning 3 A/F learning 3 % 0.0%
Throttle motor duty Throttle motor duty % –27%
Throttle power supply voltage Throttle power supply voltage V (Battery voltage)
Sub throttle sensor voltage Sub throttle sensor voltage V 1.50 V
Main throttle sensor voltage Main throttle sensor voltage V 0.64 V
Sub acceleration sensor voltage Sub acceleration sensor voltage V 0.7 V
Main acceleration sensor voltage Main acceleration sensor voltage V 0.7 V
Memory vehicle speed Memory vehicle speed km/h or MPH 0 km/h or 0 MPH
A/F compensation 4 A/F Compensation 4 % 0.31%
A/F learning 4 A/F learning 4 % 0.0%
Fuel level sensor resistance Fuel level resistanceΩ4 — 96 Ω
Oil temperature Oil Temperature °C≥ 85°C (After engine is
warmed-up.)
Oil switching solenoid valve duty R OSV duty R % 17.3%
Oil switching solenoid valve duty L OSV duty L % 17.3%
Oil switching solenoid valve current R OSV current R mA 192 mA
Oil switching solenoid valve current L OSV current L mA 192 mA
Va r i a b l e va l v e l i f t m o d e V V L L i f t M o d e — 1
#1 cylinder roughness monitor #1 cylinder roughness monitor — 0
#2 cylinder roughness monitor #2 cylinder roughness monitor — 0
#3 cylinder roughness monitor #3 cylinder roughness monitor — 0
#4 cylinder roughness monitor #4 cylinder roughness monitor — 0
#5 cylinder roughness monitor #5 cylinder roughness monitor — 0
#6 cylinder roughness monitor #6 cylinder roughness monitor — 0
Te s t m o d e t e r m i n a l Te s t m o d e t e r m i n a l — U c h e c k
Neutral position switch signal Neutral SW — Neutral
Idle switch signal Soft idle SW — In idle
Ignition switch signal Ignition SW — ON input
Pow er s te e r in g sw it c h s ig n al Powe r st ee r i ng S W i n pu t si gn a l — O FF i np u t ( w h e n OF F )
Air conditioning switch signal A/C SW — OFF input (when OFF)
Starter switch signal Starter SW — OFF input
Fr o nt ox yg e n mo n it o r 1 Fr o n t oxy ge n m on i to r 1 — Ri ch
Fr o nt ox yg e n mo n it o r 2 Fr o n t oxy ge n m on i to r 2 — Ri ch
Knocking signal Knock signal — OFF
Crankshaft position sensor signal Crankshaft angle signal — Yes
Camshaft position sensor signal Camshaft angle signal — Yes
Drain valve signal Vent. Solenoid Valve — OFF output (when OFF)
Rear defogger switch signal Rear defogger SW — OFF input (when OFF)
Blower fan switch signal Blower fan SW — OFF input (when OFF)
Light switch signal Light SW — OFF input (when OFF)
Wiper switch signal Wiper SW — OFF input (when OFF)
A/C middle pressure switch signal A/C middle pressure SW — OFF input
A/C compressor relay signal A/C compressor relay output — OFF output
AT c o o r d i n a t e r e t a r d a n g l e d e m a n d s i g n a lAT c o o r d i n a t e r e t a r d a n g l e
demand—Yes
Description Display Unit of measure Note (at idling)
EN(H6DO)(diag)-41
Drive Cycle
ENGINE (DIAGNOSTICS)
2. DRIVE CYCLE A — DRIVE THE VEHICLE WITH 80 KM/H (50 MPH) FOR 20 MINUTES, AND
THEN IDLE THE ENGINE FOR A MINUTE.
DTC Item On condition
*P0125 Insufficient Coolant Temperature For Closed Loop Fuel Control
Engine coolant temperature at
engine start is 20°C (68°F) or
less.
*P0128Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Tem-
perature)—
*P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1) —
*P0153 O2 Sensor Circuit Slow Response (Bank 2 Sensor 1) —
*P0171 System Too Lean (Bank 1)Complete diagnosis for drive
cycle B or C
*P0172 System Too Rich (Bank 1)Complete diagnosis for drive
cycle B or C
*P0174 System Too Lean (Bank 2)Complete diagnosis for drive
cycle B or C
*P0175 System Too Rich (Bank 2)Complete diagnosis for drive
cycle B or C
*P0196 Engine Oil Temperature Sensor Circuit Range/performance —
*P0301 Cylinder 1 Misfire DetectedComplete diagnosis for drive
cycle B or C
*P0302 Cylinder 2 Misfire DetectedComplete diagnosis for drive
cycle B or C
*P0303 Cylinder 3 Misfire DetectedComplete diagnosis for drive
cycle B or C
*P0304 Cylinder 4 Misfire DetectedComplete diagnosis for drive
cycle B or C
*P0305 Cylinder 5 Misfire DetectedComplete diagnosis for drive
cycle B or C
*P0306 Cylinder 6 Misfire DetectedComplete diagnosis for drive
cycle B or C
*P0420 Catalyst System Efficiency Below Threshold (Bank 1) —
*P0442 Evaporative Emission Control System Leak Detected (Small Leak)
Engine coolant temperature at
engine start is 25°C (77°F) or
less.
*P0451 Evaporative Emission Control System Pressure Sensor —
*P0456 Evaporative Emission Control System Leak Detected (Very Small Leak)
Engine coolant temperature at
engine start is 25°C (77°F) or
less.
*P0457 Evaporative Emission Control System Leak Detected (Fuel Cap Loose/ Off)
Engine coolant temperature at
engine start is 25°C (77°F) or
less.
*P0464 Fuel Level Sensor Circuit Intermittent —
P1443 Vent Control Solenoid Valve Function Problem —
*P2096 Post Catalyst Fuel Trim System Too Lean (Bank 1)Complete diagnosis for drive
cycle B or C
*P2097 Post Catalyst Fuel Trim System Too Rich (Bank 1)Complete diagnosis for drive
cycle B or C
*P2098 Post Catalyst Fuel Trim System Too Lean (Bank 2)Complete diagnosis for drive
cycle B or C
*P2099 Post Catalyst Fuel Trim System Too Rich (Bank 2)Complete diagnosis for drive
cycle B or C
P2103 Throttle Actuator Control Motor Circuit HighComplete diagnosis for drive
cycle B or C
EN(H6DO)(diag)-42
Drive Cycle
ENGINE (DIAGNOSTICS)
3. DRIVE CYCLE B — 10 MINUTES IDLING
NOTE:
Drive the vehicle in more than 10 km/h (6 MPH) before diagnosis.
DTC Item On condition
*P0126 Insufficient Coolant Temperature for Stable Operation —
*P0171 System Too Lean (Bank 1)Complete diagnosis for drive
cycle A or C
*P0172 System Too Rich (Bank 1)Complete diagnosis for drive
cycle A or C
*P0174 System Too Lean (Bank 2)Complete diagnosis for drive
cycle A or C
*P0175 System Too Rich (Bank 2)Complete diagnosis for drive
cycle A or C
*P0301 Cylinder 1 Misfire DetectedComplete diagnosis for drive
cycle A or C
*P0302 Cylinder 2 Misfire DetectedComplete diagnosis for drive
cycle A or C
*P0303 Cylinder 3 Misfire DetectedComplete diagnosis for drive
cycle A or C
*P0304 Cylinder 4 Misfire DetectedComplete diagnosis for drive
cycle A or C
*P0305 Cylinder 5 Misfire DetectedComplete diagnosis for drive
cycle A or C
*P0306 Cylinder 6 Misfire DetectedComplete diagnosis for drive
cycle A or C
*P0459 Evaporative Emission Control System Purge Control Valve Circuit High —
*P0483 Cooling Fan Rationality Check —
*P0506 Idle Control System RPM Lower Than Expected —
*P0507 Idle Control System RPM Higher Than Expected —
*P2096 Post Catalyst Fuel Trim System Too Lean (Bank 1)Complete diagnosis for drive
cycle A or C
*P2097 Post Catalyst Fuel Trim System Too Rich (Bank 1)Complete diagnosis for drive
cycle A or C
*P2098 Post Catalyst Fuel Trim System Too Lean (Bank 2)Complete diagnosis for drive
cycle A or C
*P2099 Post Catalyst Fuel Trim System Too Rich (Bank 2)Complete diagnosis for drive
cycle A or C
P2103 Throttle Actuator Control Motor Circuit HighComplete diagnosis for drive
cycle A or C
EN(H6DO)(diag)-43
Drive Cycle
ENGINE (DIAGNOSTICS)
4. DRIVE CYCLE C — DRIVE THE VEHICLE WITH FOLLOWING DRIVE PATTERNS
(A) Idle the engine for more than 10
seconds.
(D) Decelerate the vehicle to 64 km/h
(40 MPH) with throttle fully closed.
(G) Stop the vehicle with throttle fully
closed.
(B) Accelerate the vehicle to 97 km/h
(60 MPH) within 20 seconds.
(E) Drive the vehicle at 64 km/h (40
MPH) for 20 seconds.
(H) Vehicle speed km/h (MPH)
(I) Sec.
(C) Drive the vehicle at 97 km/h (60
MPH) for 20 seconds.
(F) Accelerate the vehicle to 97 km/h
(60 MPH) within 10 seconds.
DTC Item On condition
P0026 Intake Valve Control Solenoid Circuit Range/Performance (Bank 1) —
P0028 Intake Valve Control Solenoid Circuit Range/Performance (Bank 2) —
*P0030 HO2S Heater Control Circuit (Bank 1 Sensor 1) —
*P0050 HO2S Heater Control Circuit (Bank 2 Sensor 1) —
*P0068 MAP/MAF - Throttle Position Correlation —
P0076 Intake Valve Control Circuit Low (Bank 1) —
P0082 Intake Valve Control Circuit Low (Bank 2) —
*P0101 Mass or Volume Air Flow Circuit Range/Performance —
P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1) —
*P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2) —
P0154 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 1) —
*P0159 O2 Sensor Circuit Slow Response (Bank 2 Sensor 2) —
*P0171 System Too Lean (Bank 1) Complete diagnosis for drive cycle A or B
*P0172 System Too Rich (Bank 1) Complete diagnosis for drive cycle A or B
*P0174 System Too Lean (Bank 2) Complete diagnosis for drive cycle A or B
*P0175 System Too Rich (Bank 2) Complete diagnosis for drive cycle A or B
*P0301 Cylinder 1 Misfire Detected Complete diagnosis for drive cycle A or B
*P0302 Cylinder 2 Misfire Detected Complete diagnosis for drive cycle A or B
*P0303 Cylinder 3 Misfire Detected Complete diagnosis for drive cycle A or B
*P0304 Cylinder 4 Misfire Detected Complete diagnosis for drive cycle A or B
*P0305 Cylinder 5 Misfire Detected Complete diagnosis for drive cycle A or B
*P0306 Cylinder 6 Misfire Detected Complete diagnosis for drive cycle A or B
P2103 Throttle Actuator Control Motor Circuit High Complete diagnosis for drive cycle A or B
EN-00842
(C)
(H)
(I)
(60)97
64(40)(B)
(A)
(F)(D)
(E)
150100500
(G)
EN(H6DO)(diag)-72
List of Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
P0182 Fuel Temperature Sensor “A” Circuit
Low Input
ble Code (DTC).>
P0183 Fuel Temperature Sensor “A” Circuit
High Input
ble Code (DTC).>
P0196 Engine Oil Temperature Sensor Cir-
cuit Range/Performance
Diagnostic Trouble Code (DTC).>
P0197 Engine Oil Temperature Sensor Cir-
cuit Low
Code (DTC).>
P0198 Engine Oil Temperature Sensor Cir-
cuit High
Code (DTC).>
P0222 Throttle/Pedal Position Sensor/
Switch “B” Circuit Low Input
Diagnostic Trouble Code (DTC).>
P0223 Throttle/Pedal Position Sensor/
Switch “B” Circuit High Input
Diagnostic Trouble Code (DTC).>
P0230 Fuel Pump Primary Circuit
P0301 Cylinder 1 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P0303 Cylinder 3 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P0305 Cylinder 5 Misfire Detected
P0306 Cylinder 6 Misfire Detected
P0327 Knock Sensor 1 Circuit Low Input
(Bank 1 or Single Sensor)
Diagnostic Trouble Code (DTC).>
P0328 Knock Sensor 1 Circuit High Input
(Bank 1 or Single Sensor)
Diagnostic Trouble Code (DTC).>
P0332 Knock Sensor 2 Circuit Low Input
(Bank 2)
(DTC).>
P0333 Knock Sensor 2 Circuit High Input
(Bank 2)
(DTC).>
P0335 Crankshaft Position Sensor “A” Cir-
cuit
(DTC).>
P0336 Crankshaft Position Sensor “A” Cir-
cuit Range/Performance
Diagnostic Trouble Code (DTC).>
P0340 Camshaft Position Sensor “A” Circuit
(Bank 1 or Single Sensor)
with Diagnostic Trouble Code (DTC).>
DTC Item Reference