1997 SUBARU LEGACY sensor

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
131
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M1056
B: DTC P0101
—MASS AIR FLOW SENSOR CIRCUIT
RANGE/PERFORMANCE PROBLEM
(LOW INPUT)—
DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
TROUBLE SYMPTOM:

Erroneous idling

Engine stalls.

Poor driving performance
WIRING DIAGRAM:
B2M1057
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

132
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10B1CHECK DTC P0102 OR P0103 ON DIS-
PLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0102 or
P0103?
: Inspect DTC P0102 or P0103 using“10. Diagnos-
tics Chart with Trouble Code”. [T10A0].>
NOTE:
In this case, it is not necessary to inspect DTC P0101.
: Replace mass air flow sensor.
133
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M1058
C: DTC P0102
—MASS AIR FLOW SENSOR CIRCUIT LOW
INPUT—
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Erroneous idling

Engine stalls.

Poor driving performance
WIRING DIAGRAM:
B2M1057
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

134
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0145A
10C1CONNECT SUBARU SELECT MONITOR
OR THE OBD-II GENERAL SCAN TOOL,
AND READ DATA.
1) Turn ignition switch to OFF.
2) Connect Subaru Select Monitor or the OBD-II general
scan tool to data link connector.
3) Turn ignition switch to ON and Subaru Select Monitor or
the OBD-II general scan tool switch to ON.
4) Start engine.
B2M0481
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F06

F06: Mass air flow and voltage input from mass air flow
sensor are shown on display at the same time.
: Is the value equal to or more than 1.3 g/sec
or 0.3 V and equal to or less than 250 g/sec
or 5.0 V in function mode F06?
Probable cause: Poor connect of connectors, circuit and
grounding line.
: Even if MIL lights up, the circuit has returned to a
normal condition at this time. A temporary poor
contact of the connector or harness may be the
cause. Repair harness or connector in the mass
air flow sensor.
NOTE:
In this case, repair the following:

Open or ground short circuit in harness between mass
air flow sensor and ECM connector

Poor contact in mass air flow sensor or ECM connector
: Go to step10C2.
135
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M0532A
10C2CHECK INPUT SIGNAL FOR ECM.
(USING VOLTAGE METER AND SUBARU
SELECT MONITOR.)
Measure voltage between ECM connector and chassis
ground while engine is idling.
: Connector & terminal
(B84) No. 5 (+)—Chassis ground ():
Is the voltage less than 0.3 V?
: Go to step10C3.
: Go to next.
B2M0481
: Does the voltage change more than 0.3 V by
shaking harness and connector of ECM
while monitoring the value with Subaru
select monitor?
: Repair poor contact in ECM connector.
: Contact with SOA service.
NOTE:
Inspection by DTM is required, because probable cause is
deterioration of multiple parts.
B2M0645A
10C3CHECK POWER SUPPLY TO MASS AIR
FLOW SENSOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from mass air flow sensor.
3) Turn ignition switch to ON.
4) Measure voltage between mass air flow sensor connec-
tor and engine ground.
: Connector & terminal
(B3) No. 1 (+)—Engine ground ():
Is the voltage more than 10 V?
: Go to step10C4.
: Repair open circuit in harness between main relay
and mass air flow sensor connector.
136
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M1059A
10C4CHECK HARNESS BETWEEN ECM AND
MASS AIR FLOW SENSOR CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between ECM and
mass air flow sensor connector.
: Connector & terminal
(B84) No. 5—(B3) No. 4:
Is the resistance less than 1Ω?
: Go to next.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and mass air flow
sensor connector

Poor contact in mass air flow sensor connector

Poor contact in ECM connector
: Connector & terminal
(B84) No. 53—(B3) No. 3:
Is the resistance less than 1Ω?
: Go to step10C5.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and mass air flow
sensor connector

Poor contact in mass air flow sensor connector

Poor contact in ECM connector
B2M1060A
10C5CHECK HARNESS BETWEEN ECM AND
MASS AIR FLOW SENSOR CONNECTOR.
Measure resistance of harness between ECM connector
and chassis ground.
: Connector & terminal
(B84) No. 5—Chassis ground:
Is the resistance more than 1 MΩ?
: Replace mass air flow sensor.
: Repair ground short circuit in harness between
ECM and mass air flow sensor connector.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles