SUBARU LEGACY 1997 Service Repair Manual

B2M0610A
3) Measure resistance of harness between ECM and sub
fan relay 1 (with A/C models) or main fan relay (without A/C
models) connector.
: Connector & terminal
(B84) No. 74—(F40) 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 sub fan relay
1 (with A/C models) or main fan relay (without A/C models)
connector

Poor contact in coupling connector (F45)

Replace diode (A/C)
: Is there poor contact in ECM or sub fan
relay 1 (with A/C models) or main fan relay
(without A/C models) connector?
: Repair poor contact in ECM or sub fan relay 1 (with
A/C models) or main fan relay (without A/C mod-
els) connector.
: Contact with SOA service.
NOTE:
Inspection by DTM is required, because probable cause is
deterioration of multiple parts.
400
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0538
CU: DTC P1502
—RADIATOR FAN FUNCTION PROBLEM—
DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
TROUBLE SYMPTOM:

Occurrence of noise

Overheating
WIRING DIAGRAM:
B2M1290
401
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

NOTE:
If the vehicle, with the engine idling, is placed very close to
a wall or another vehicle, preventing normal cooling
function, the OBD system may detect malfunction.
10CU1CHECK ANY OTHER DTC (BESIDE DTC
P1502) ON DISPLAY.
: Is there any other DTC on display?
: Inspect the relevant DTC using“10. Diagnostics
Chart with Trouble Code”.
: Check engine cooling system. [K100].>
402
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M1140
CV: DTC P1507
—IDLE CONTROL SYSTEM MALFUNCTION
(FAIL-SAFE)—
DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
TROUBLE SYMPTOM:

Engine keeps running at higher revolution than specified
idling revolution.
WIRING DIAGRAM:
B2M1311
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

403
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10CV1
CHECK DTC P0505 ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0505?
: Inspect DTC P0505 using“10. Diagnostics Chart
with Trouble Code”.
NOTE:
In this case, it is not necessary to inspect DTC P1507.
: Go to step10CV2.
10CV2
CHECK AIR INTAKE SYSTEM.
1) Turn ignition switch to ON.
2) Start engine, and idle it.
: Is there a fault in air intake system?
NOTE:
Check the following items.

Loose installation of intake manifold, idle air control sole-
noid valve and throttle body

Cracks of intake manifold gasket, idle air control sole-
noid valve gasket and throttle body gasket

Loose connections and cracks of idle air control solenoid
valve by-pass hoses

Disconnections of vacuum hoses
: Repair air suction and leaks.
: Replace idle air control solenoid valve.
404
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M1141
CW: DTC P1520
—RADIATOR FAN RELAY 1 CIRCUIT HIGH
INPUT—
DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
TROUBLE SYMPTOM:

Radiator fan does not operate properly.

Overheating
WIRING DIAGRAM:
B2M1289
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODE.

405
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0736A
10CW1
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to OFF.
2) Connect test mode connector at the lower portion of
instrument panel (on the driver’s side), to the side of the
center console box.
3) Turn ignition switch to ON.
B2M0608A
4) Measure voltage between ECM and chassis ground.
: Connector & terminal
(B84) No. 74 (+)—Chassis ground:
Does voltage change between 0 and 10
volts?
NOTE:
Radiator fan relay operation check can be executed using
Subaru Select Monitor (Function mode: FD03). For
procedure, refer to“COMPULSORY VALVE OPERATION
CHECK MODE”.
: Go to step10CW2.
: Even if MIL lights up, the circuit has returned to a
normal condition at this time. In this case, repair
poor contact in ECM connector.
B2M0611A
10CW2CHECK SHORT CIRCUIT IN RADIATOR
FAN RELAY 1 CONTROL CIRCUIT.
1) Turn ignition switch to OFF.
2) Remove main fan relay 1 and sub fan relay 1. (with A/C
models)
Remove main fan relay. (without A/C models)
3) Disconnect test mode connector.
4) Turn ignition switch to ON.
5) Measure voltage between ECM and chassis ground.
: Connector & terminal
(B84) No. 74 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Repair battery short circuit in radiator fan relay 1
control circuit. After repair, replace ECM.
: Go to next.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Replace ECM.
406
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

B2M1142
CX: DTC P1540
—VEHICLE SPEED SENSOR MALFUNCTION
2—
DTC DETECTING CONDITION:

Immediately at fault recognition
WIRING DIAGRAM:
B2M1285
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

407
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

10CX1CHECK SPEEDOMETER OPERATION IN
COMBINATION METER.
: Does speedometer operate normally?
: Go to step10CX2.
: Check speedometer and vehicle speed sensor
.
B2M0573A
10CX2CHECK HARNESS BETWEEN ECM AND
COMBINATION METER CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from TCM.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and chassis ground.
: Connector & terminal
(B84) No. 83 (+)—Chassis ground ():
Is the voltage more than 2 V?
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and combination
meter connector

Poor contact in ECM connector

Poor contact in combination meter connector

Poor contact in coupling connector (B37)
: Go to step10CX3.
B2M0574A
10CX3CHECK HARNESS BETWEEN ECM AND
COMBINATION METER CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between ECM connec-
tor and chassis ground.
: Connector & terminal
(B84) No. 83—Chassis ground:
Is the resistance less than 10Ω?
: Repair ground short circuit in harness between
ECM and combination meter connector.
: Repair poor contact in ECM connector.
408
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles

OBD0501
CY: DTC P1700
—THROTTLE POSITION SENSOR CIRCUIT
MALFUNCTION FOR AUTOMATIC
TRANSMISSION—
DTC DETECTING CONDITION:

Two consecutive driving cycles with fault
TROUBLE SYMPTOM:

Shift point too high or too low; engine brake not effected
in“3”range; excessive shift shock; excessive tight corner
“braking”
WIRING DIAGRAM:
B2M0613
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

409
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostic Chart with Trouble Code for LHD Vehicles