1997 SUBARU LEGACY fuel

Symptom Problem parts
7. Spark knock1) Mass air flow sensor
2) Engine coolant temperature sensor
3) Knock sensor
4) Fuel injection parts (*4)
5) Fuel pump and fuel pump relay
8. After burning in exhaust system1) Mass air flow sensor
2) Engine coolant temperature sensor (*2)
3) Fuel injection parts (*4)
4) Fuel pump and fuel pump relay
*1: Check ignitor, ignition coil and spark plug.
*2: Indicate the symptom occurring only in cold temperatures.
*3: Ensure the secure installation.
*4: Check fuel injector, fuel pressure regulator and fuel filter.
*5: Inspect air leak in air intake system.
*6: Adjust accelerator cable.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
9. General Diagnostic Table

10. Diagnostic Chart with Trouble Code
for LHD Vehicles
A: DIAGNOSTIC TROUBLE CODE (DTC) LIST
DTC
No.Abbreviation
(Subaru Select Monitor)Item Page
P0101 QA
—RLOW Mass air flow sensor circuit range/performance problem (low input) 132
P0102 QA
—LOW Mass air flow sensor circuit low input 134
P0103 QA
—HI Mass air flow sensor circuit high input 138
P0106 PS
—R2 Pressure sensor circuit range/performance problem 141
P0107 P
—SLOW Pressure sensor circuit low input 145
P0108 P
—SHI Pressure sensor circuit high input 149
P0116 TW
—LOW Engine coolant temperature sensor circuit low input 154
P0117 TW
—HI Engine coolant temperature sensor circuit high input 157
P0121 TH
—RHI Throttle position sensor circuit range/performance problem (high input) 160
P0122 THV
—LOW Throttle position sensor circuit low input 162
P0123 THV
—HI Throttle position sensor circuit high input 167
P0125 TW
—CL Insufficient coolant temperature for closed loop fuel control 170
P0130 FO2
—V Front oxygen sensor circuit malfunction 172
P0133 FO2
—R Front oxygen sensor circuit slow response 175
P0135 FO2H Front oxygen sensor heater circuit malfunction 177
P0136 RO2
—V Rear oxygen sensor circuit malfunction 181
P0139 RO2
—R Rear oxygen sensor circuit slow response 184
P0141 RO2H Rear oxygen sensor heater circuit malfunction 186
P0170 FUEL Fuel trim malfunction 190
P0181 TNKT
—F Fuel temperature sensor A circuit range/performance problem 195
P0182 TNKT
—LOW Fuel temperature sensor A circuit low input 197
P0183 TNKT
—HI Fuel temperature sensor A circuit high input 200
P0261 INJ1 Fuel injector circuit low input - #1 203
P0262 INJ1
—HI Fuel injector circuit high input - #1 207
P0264 INJ2 Fuel injector circuit low input - #2 203
P0265 INJ2
—HI Fuel injector circuit high input - #2 207
P0267 INJ3 Fuel injector circuit low input - #3 203
P0268 INJ3
—HI Fuel injector circuit high input - #3 207
P0270 INJ4 Fuel injector circuit low input - #4 203
P0271 INJ4
—HI Fuel injector circuit high input - #4 207
P0301 MIS
—1 Cylinder 1 misfire detected 211
P0302 MIS
—2 Cylinder 2 misfire detected 211
P0303 MIS
—3 Cylinder 3 misfire detected 211
P0304 MIS
—4 Cylinder 4 misfire detected 211
P0325 KNOCK Knock sensor circuit malfunction 219
P0335 CRANK Crankshaft position sensor circuit malfunction 222
P0336 CRANK
—R Crankshaft position sensor circuit range/performance problem 225
P0340 CAM Camshaft position sensor circuit malfunction 227
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

DTC
No.Abbreviation
(Subaru Select Monitor)Item Page
P0341 CAM
—R Camshaft position sensor circuit range/performance problem 230
P0400 EGR Exhaust gas recirculation flow malfunction 232
P0403 EGRSOL Exhaust gas recirculation circuit low input 237
P0420 CAT Catalyst system efficiency below threshold 240
P0440 EVAP Evaporative emission control system malfunction 242
P0441 CPC
—F Evaporative emission control system incorrect purge flow 246
P0443 CPC Evaporative emission control system purge control valve circuit low input 248
P0446 VCMSOL
—LO Evaporative emission control system vent control low input 251
P0451 TNKP
—F Evaporative emission control system pressure sensor range/performance problem 254
P0452 TNKP
—LOW Evaporative emission control system pressure sensor low input 256
P0453 TNKP
—HI Evaporative emission control system pressure sensor high input 261
P0461 FLVL
—R Fuel level sensor circuit range/performance problem 267
P0462 FLVL
—LOW Fuel level sensor circuit low input 269
P0463 FLVL
—HI Fuel level sensor circuit high input 275
P0500 VSP Vehicle speed sensor malfunction 281
P0505 ISC Idle control system malfunction 283
P0506 ISC
—RLOW Idle control system RPM lower than expected 289
P0507 ISC
—RHI Idle control system RPM higher than expected 291
P0600—Serial communication link malfunction 293
P0601 RAM Internal control module memory check sum error 295
P0703 ATBRK Brake switch input malfunction 296
P0705 ATRNG Transmission range sensor circuit malfunction 299
P0710 ATF Transmission fluid temperature sensor circuit malfunction 311
P0720 ATVSP Output speed sensor (vehicle speed sensor 1) circuit malfunction 312
P0725 ATNE Engine speed input circuit malfunction 313
P0731 ATGR1 Gear 1 incorrect ratio 314
P0732 ATGR2 Gear 2 incorrect ratio 314
P0733 ATGR3 Gear 3 incorrect ratio 314
P0734 ATGR4 Gear 4 incorrect ratio 314
P0740 ATLU
—F Torque converter clutch system malfunction 317
P0743 ATLU Torque converter clutch system electrical 321
P0748 ATPL Pressure control solenoid electrical 322
P0753 ATSFT1 Shift solenoid A electrical 323
P0758 ATSFT2 Shift solenoid B electrical 324
P0760 ATOVR
—F Shift solenoid C malfunction 325
P0763 ATOVR Shift solenoid C electrical 328
P1100 ST
—SWOFF Starter switch circuit low input 329
P1101 N
—SW Neutral position switch circuit malfunction [MT vehicles] 331
P1101 N
—SWOFF Neutral position switch circuit high input [AT vehicles] 335
P1102 BR Pressure sources switching solenoid valve circuit low input 340
P1103 TRQ Engine torque control signal circuit malfunction 343
P1104 TCS
—LOW TCS signal circuit low input 346
130
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

DTC
No.Abbreviation
(Subaru Select Monitor)Item Page
P1120 ST
—SWON Starter switch circuit high input 348
P1121 N
—SWON Neutral position switch circuit low input [AT vehicles] 350
P1122 BR
—HI Pressure sources switching solenoid valve circuit high input 354
P1124 TCS
—HI TCS signal circuit high input 357
P1141 QA
—RHI Mass air flow sensor circuit range/performance problem (high input) 360
P1142 TH
—RLOW Throttle position sensor circuit range/performance problem (low input) 362
P1143 PS
—RLOW Pressure sensor circuit range/performance problem (low input) 364
P1144 PS
—RHI Pressure sensor circuit range/performance problem (high input) 368
P1400 PCVSOL
—LO Fuel tank pressure control solenoid valve circuit low input 370
P1420 PCVSOL
—HI Fuel tank pressure control solenoid valve circuit high input 374
P1421 EGRSOL
—HI Exhaust gas recirculation circuit high input 377
P1422 CPC
—HI Evaporative emission control system purge control valve circuit high input 380
P1423 VCMSOL
—HI Evaporative emission control system vent control high input 383
P1440 PCV
—FLOW Fuel tank pressure control system function problem (low input) 386
P1441 PCV
—FHI Fuel tank pressure control system function problem (high input) 390
P1442 FLVL
—R2 Fuel level sensor circuit range/performance problem 2 393
P1500 FAN
—1 Radiator fan relay 1 circuit low input 395
P1502 FAN
—F Radiator fan function problem 401
P1507 ISC
—SHI Idle control system malfunction (fail-safe) 403
P1520 FAN
—1HI Radiator fan relay 1 circuit high input 405
P1540 VSP
—S Vehicle speed sensor malfunction 2 407
P1700 ATTH Throttle position sensor circuit malfunction for automatic transmission 409
P1701 ATCRS Cruise control set signal circuit malfunction for automatic transmission 411
P1702 ATDIAG
—LO Automatic transmission diagnosis input signal circuit low input 413
P1722 ATDIAG
—HI Automatic transmission diagnosis input signal circuit high input 416
P1742 ATDIAG
—2 Automatic transmission diagnosis input signal circuit malfunction 419
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0191
M: DTC P0125
—INSUFFICIENT COOLANT TEMPERATURE
FOR CLOSED LOOP FUEL CONTROL—
DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
TROUBLE SYMPTOM:

Engine would not return to idling.
WIRING DIAGRAM:
B2M0539
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10N1CHECK FOR OTHER CAUSES AFFECT-
ING EXHAUST GAS.
: Is CO % more than 2 % after engine warm-
up?
: Check fuel system.
NOTE:

Check for use of improper fuel.

Check if engine oil or coolant level is extremely low.
: Go to step10N2.
OBD0145A
10N2
CHECK FRONT OXYGEN SENSOR DATA.
1) Turn ignition switch to OFF.
2) Connect the Subaru Select Monitor or the OBD-II gen-
eral scan tool to data link connector.
3) Start engine and Turn the Subaru Select Monitor and
the OBD-II general scan tool switch to ON.
4) Warm-up the engine until coolant temperature is above
70°C (160°F) and keep the engine speed at 2,000 rpm to
3,000 rpm for one minute.
B2M0487
5) Read data on Subaru Select Monitor or the OBD-II gen-
eral scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F12

F12: Front oxygen sensor max. and min. output signals
are indicated at the same time.
: Is the difference of voltage less than 0.1 V
between the value of max. output and min.
output with function mode F12?
: Go to step10N3.
: Replace front oxygen sensor.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10Q1
CHECK DTC P0130 ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0130?
: Go to step10Q2.
: Go to step10Q3.
10Q2
CHECK FAILURE CAUSE OF P0130.
Perform the step 1 of DTC P0130.
: Is the failure cause of P0130 in the fuel sys-
tem?
: Check fuel system.
NOTE:
In this case, it is not necessary to inspect DTC P0136.
: Go to step10Q3.
OBD0145A
10Q3
CHECK REAR OXYGEN SENSOR DATA.
1) Turn ignition switch to OFF.
2) Connect Subaru Select Monitor or OBD-II general scan
tool to data link connector.
3) Start the engine, and turn Subaru Select Monitor or
OBD-II general scan tool switch to ON.
4) Warm-up the engine until engine coolant temperature is
above 70°C (160°F), and keep the engine speed at 2,000
rpm to 3,000 rpm for two minutes.
B2M0488
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F13

F13: Rear oxygen sensor output signal is indicated.
: Does the value fluctuate in function mode
F13?
: Go to step10Q5.
: Go to next.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0240
T: DTC P0170
—FUEL TRIM MALFUNCTION—
DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
TROUBLE SYMPTOM:

Erroneous idling

Engine stalls.

Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODE.

10T1
CHECK EXHAUST SYSTEM.
: Are there holes or loose bolts on exhaust
system?
: Repair exhaust system.
: Go to step10T2.
10T2
CHECK AIR INTAKE SYSTEM.
: Are there holes, loose bolts or disconnec-
tion of hose on air intake system?
: Repair air intake system.
: Go to step10T3.
G2M0340
10T3
CHECK FUEL PRESSURE.
1) Release fuel pressure.
(1) Remove fuel pump access hole lid located on the
right rear of trunk compartment floor (Sedan) or lug-
gage compartment floor (Wagon).
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles