Temp sensor SUBARU LEGACY 1995 Service Owner's Manual

5. Specified Data
1. ENGINE CONTROL MODULE (ECM) I/O SIGNAL
OBD0092A
ContentConnector
No.Terminal
No.Signal (V)
Note Ignition SW
Engine ON (Idling)
ON (Engine OFF)
Crankshaft
position
sensorSignal (+) B84 8 0 ±7 Sensor output waveform
Signal () B84 7 0 0—
Shield B84 52 0 0—
Camshaft
position
sensorSignal (+) B84 6 0 ±7 Sensor output waveform
Signal () B84 5 0 0—
Shield B84 52 0 0—
Mass air
flow
sensorSignal B84 26 0—0.3 0.8—1.2—
Shield B84 54 0 0—
GND B84 25 0 0—
Throttle
position
sensorSignal B84 24Fully closed: 0.2—1.0
Fully opened: 4.2—4.7—
Power
supplyB84 22 5 5—
GND B84 25 0 0—
Front
oxygen
sensorSignal B84 28 0 0)0.9—
Shield B84 56 0 0—
Rear
oxygen
sensorSignal B84 27 0 0)0.9—
Shield B84 56 0 0—
Engine coolant
temperature sensorB84 29 1.0—1.4 1.0—1.4 After warm-up
Vehicle speed sensor
2B84 57 0or5 0or5“5”and“0”are repeatedly
displayed when vehicle is
driven.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

ContentConnector
No.Terminal
No.Measuring conditionsVoltage
(V)Resistance to
body
(ohms)
Throttle position
sensorB54 8Throttle fully closed. 0.3—0.7
—
Throttle fully open. 4.3—4.9
Throttle position
sensor power
supplyB56 19Ignition switch ON (with engine
OFF)4.8—5.3—
ATF temperature
sensorB54 10ATF temperature 20°C(68°F) 2.9—4.0 2.1 k—2.9 k
ATF temperature 80°C (176°F) 1.0—1.4 275—375
Vehicle speed
sensor 1B54 12Vehicle stopped. 0
450—720
Vehicle speed at least 20 km/h (12
MPH)More than 1 (AC range)
Vehicle speed
sensor 2B56 11When vehicle is slowly moved at
least 2 meters (7ft).Less than 1)More than 9—
Engine speed
signalB54 5Ignition switch ON (with engine
OFF).More than 10.5
—
Ignition switch ON (with engine ON). 8—11
Cruise set signal B56 3When cruise control is set (SET
lamp ON).Less than 1
—
When cruise control is not set (SET
lamp OFF).More than 6.5
Torque control
signalB55 16 Ignition switch ON 4—6—
Torque control cut
signalB56 16 Ignition switch ON 6—9—
Mass air flow
signalB54 9 Engine idling after warm-up 0.5—1.2—
Shift solenoid 1 B55 141st or 4th gear More than 9
20—32
2nd or 3rd gear Less than 1
Shift solenoid 2 B55 131st or 2nd gear More than 9
20—32
3rd or 4th gear Less than 1
Shift solenoid 3 B55 15Selector lever in“N”range (with
throttle fully closed).Less than 1
20—32
Selector lever in“D”range (with
throttle fully closed).More than 9
Duty solenoid A B55 8Throttle fully closed (with engine
OFF) after warm-up.1.5—4.0
1.5—4.5
Throttle fully open (with engine
OFF) after warm-up.Less than 0.5
Dropping resistor B55 7Throttle fully closed (with engine
OFF) after warm-up.5—14
12—18
Throttle fully open (with engine
OFF) after warm-up.Less than 0.5
Duty solenoid B B55 5When lock up occurs. More than 8.5
9—17
When lock up is released. Less than 0.5
Duty solenoid C
(AWD model only)B55 3Fuse on FWD switch More than 8.5
9—17 Fuse removed from FWD switch
(with throttle fully open and with
select lever in 1st gear).Less than 0.5
Sensor ground
line 1B54 7—0 Less than 1
Sensor ground
line 2B56 20—0 Less than 1
System ground
lineB56 1—0 Less than 1
Power system
ground lineB55 10—0 Less than 1
FWD switch
(AWD model only)B56 2Fuse removed. 6—9.1
—
Fuse installed. Less than 1
Data link signal
(Subaru select
monitor)B5612——
—
13——
AT diagnosis
signalB56 11 Ignition switch ON Less than 1)More than 4—
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
5. Specified Data

10. General Diagnostics Table
1. FOR ENGINE
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Problem parts
Mass air flow sensor
Engine coolant temperature sensor (*1)
Throttle position sensor
Crankshaft position sensor & Camshaft position sensor (*2)
Idle air control solenoid valve
Knock sensor
Purge control solenoid valve
EGR valve
Fuel injection parts (*3)
Ignition parts (*4)
Fuel pump and relay
A/C switch and A/C cut relay
Engine torque control signal circuitSymptom
1 Engine stalls during idling.   
2 Rough idling    
3 Engine does not return to idle.
4 Poor acceleration   
5Engine stalls or engine sags or hesi-
tates at acceleration.    
6 Surge   
7 Spark knock
8 After burning in exhaust system  
*1: The mark,, indicates the symptom occurring only in cold temperatures.
*2: For items with the mark,, ensure the secure installation of crankshaft position sensor and camshaft position sensor. Replacement is
not necessary.
*3: Check fuel injector, fuel pressure regulator and fuel filter.
*4: Check igniter, ignition coil and spark plug.
NOTE:
Malfunction of parts other than the above is also possible. Refer to 1. Engine Trouble in General [K100] in Repair Section 2-3 of the Ser-
vice Manual.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. General Diagnostics Table

2. FOR AT
Problem parts
Inhibitor switch
Control module
Vehicle speed sensor 1
Vehicle speed sensor 2
Select cable
Select lever
FWD switch
Starter motor and harness
Throttle position sensor
Hold switch
Accumulator (“N”—“D”)
Accumulator (2A)
Accumulator (4A)
Accumulator (3R)
ATF temperature sensor
Strainer
Duty solenoid A
Duty solenoid B
Shift solenoid 1
Shift solenoid 2
Shift solenoid 3
Control valve
Detent spring
Manual plate
Transfer clutch
Transfer valve
Transfer pipe
Duty solenoid C
Forward clutch
Symptom1234567891011121314151617181920212223242526272829
Starter does not rotate when select lever is
in“P”or“N.”; starter rotates when select
lever is“R”,“D”,“3”or“2.”
Abnormal noise when select lever is in“P”or
“N.”
Hissing noise occurs during standing starts.
Noise occurs while driving in“D
1”range.
Noise occurs while driving in“D
2”range.
Noise occurs while driving in“D
3”range.
Noise occurs while driving in“D
4”range.
Engine stalls while shifting from one range to
another.
Vehicle moves when select lever is in“N.”
Shock occurs when select lever is moved
from“N”to“D.” 
Excessive time lag occurs when select lever
is moved from“N”to“D.”
Shock occurs when select lever is moved
from“N”to“R.”
Excessive time lag occurs when select lever
is moved from“N”to“R.”
Vehicle does not start in any shift range
(engine revving up).
Vehicle does not start in any shift range
(engine stall).
Vehicle does not start in“R”range only
(engine revving up). 
Vehicle does not start in“R”range only
(engine stall).
Vehicle does not start in“D”or“3”range
(engine revving up).
Vehicle does not start in“D”,“3”or“2”range
(engine revving up).
Vehicle does not start in“D”,“3”or“2”range
(engine stall).
Vehicle starts in“R”range only (engine rev-
ving up).
Acceleration during standing starts is poor
(high stall rpm).
Acceleration during standing starts is poor
(low stall rpm).
Acceleration is poor when select lever is in
“D”,“3”or“2”range (normal stall rpm).
Acceleration is poor when select lever is in
“R”(normal stall rpm).
No shift occurs from 1st to 2nd gear.   
No shift occurs from 2nd to 3rd gear.
No shift occurs from 3rd to 4th gear.
No“kick-down”shifts occur.
Engine brake is not effected when select
lever is in“3”range.  
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129
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. General Diagnostics Table

Problem parts
Inhibitor switch
Control module
Vehicle speed sensor 1
Vehicle speed sensor 2
Select cable
Select lever
FWD switch
Starter motor and harness
Throttle position sensor
Hold switch
Accumulator (“N”—“D”)
Accumulator (2A)
Accumulator (4A)
Accumulator (3R)
ATF temperature sensor
Strainer
Duty solenoid A
Duty solenoid B
Shift solenoid 1
Shift solenoid 2
Shift solenoid 3
Control valve
Detent spring
Manual plate
Transfer clutch
Transfer valve
Transfer pipe
Duty solenoid C
Forward clutch
Symptom1234567891011121314151617181920212223242526272829
Engine brake is not effected when select
lever is in“3”or“2”range.
Engine brake is not effected when select
lever is in“1”range.
Shift characteristics are erroneous.  
No lock-up occurs.
Vehicle cannot be set in“D”range power
mode.
“D”range power mode cannot be released.
Parking brake is not effected.
Shift lever cannot be moved or is hard to
move from“P”range.
Select lever is hard to move. 
Select lever is too light to move (unreason-
able resistance).
ATF spurts out.
Differential oil spurts out.
Differential oil level changes excessively.
Odor is produced from oil supply pipe.
Shock occurs when select lever is moved
from“1”to“2”range.  
Slippage occurs when select lever is moved
from“1”to“2”range.  
Shock occurs when select lever is moved
from“2”to“3”range.
Slippage occurs when select lever is moved
from“2”to“3”range.
Shock occurs when select lever is moved
from“3”to“4”range.   
Slippage occurs when select lever is moved
from“3”to“4”range.   
Shock occurs when select lever is moved
from“3”to“2”range.
Shock occurs when select lever is moved
from“D”to“1”range.
Shock occurs when select lever is moved
from“2”to“1”range.
Shock occurs when accelerator pedal is
released at medium speeds.
Vibration occurs during straight-forward
operation.
Select lever slips out of position during
acceleration or while driving on rough terrain. 
Vibration occurs during turns (tight corner
“braking”phenomenon).    
Front wheel slippage occurs during standing
starts.      
Vehicle is not set in FWD mode. 
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. General Diagnostics Table

11. Diagnostics Chart with Trouble
Code
A: DIAGNOSTIC TROUBLE CODE (DTC) LIST
DTC
No.Abbreviation
(Subaru select monitor)Item Page
P0100 QA Mass air flow sensor circuit malfunction 135
P0101 QA
—R Mass air flow sensor circuit range/performance problem 141
P0105 P
—S Pressure sensor circuit malfunction 144
P0106 P
—R Pressure sensor circuit range/performance problem 151
P0115 TW Engine coolant temperature sensor circuit malfunction 156
P0120 THV Throttle position sensor circuit malfunction 161
P0121 TH
—R Throttle position sensor circuit range/performance problem 167
P0125 TW
—CL Insufficient coolant temperature for closed loop fuel control 169
P0130 FO2
—V Front oxygen sensor circuit malfunction 171
P0133 FO2
—R Front oxygen sensor circuit slow response 177
P0135 FO2H Front oxygen sensor heater circuit malfunction 180
P0136 RO2
—V Rear oxygen sensor circuit malfunction 185
P0139 RO2
—R Rear oxygen sensor circuit slow response 190
P0141 RO2H Rear oxygen sensor heater circuit malfunction 193
P0170 FUEL Fuel trim malfunction 198
P0201 INJ1 Fuel injector circuit malfunction - #1
203 P0202 INJ2 Fuel injector circuit malfunction - #2
P0203 INJ3 Fuel injector circuit malfunction - #3
P0204 INJ4 Fuel injector circuit malfunction - #4
P0301 MIS
—1 Cylinder 1 misfire detected
210 P0302 MIS
—2 Cylinder 2 misfire detected
P0303 MIS
—3 Cylinder 3 misfire detected
P0304 MIS
—4 Cylinder 4 misfire detected
P0325 KNOCK Knock sensor circuit malfunction 217
P0335 CRANK Crankshaft position sensor circuit malfunction 221
P0340 CAM Camshaft position sensor circuit malfunction 225
P0400 EGR Exhaust gas recirculation flow malfunction 229
P0403 EGRSOL Exhaust gas recirculation circuit malfunction 235
P0420 CAT Catalyst system efficiency below threshold 240
P0441 CPC
—F Evaporative emission control system incorrect purge flow 244
P0443 CPC Evaporative emission control system purge control valve circuit malfunction 248
P0500 VSP Vehicle speed sensor malfunction 253
P0505 ISC Idle control system malfunction 256
P0506 ISC
—L Idle control system RPM lower than expected 262
P0507 ISC
—H Idle control system RPM higher than expected 264
P0600—Serial communication link malfunction 266
P0601 RAM Internal control module memory check sum error 268
P0703 BRK Brake switch input malfunction 271
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

DTC
No.Abbreviation
(Subaru select monitor)Item Page
P0705 RNG Transmission range sensor circuit malfunction 274
P0710 ATF Transmission fluid temperature sensor circuit malfunction 279
P0720 ATVSP Output speed sensor (vehicle speed sensor 1) circuit malfunction 281
P0725 ATNE Engine speed input circuit malfunction 283
P0731 GR
—1 Gear 1 incorrect ratio
285 P0732 GR
—2 Gear 2 incorrect ratio
P0733 GR
—3 Gear 3 incorrect ratio
P0734 GR
—4 Gear 4 incorrect ratio
P0740 LU
—F Torque converter clutch system malfunction 289
P0743 LU Torque converter clutch system electrical 294
P0748 PL Pressure control solenoid electrical 296
P0753 SFT1 Shift solenoid A electrical 298
P0758 SFT2 Shift solenoid B electrical 300
P0760 OVR
—F Shift solenoid C malfunction 302
P0763 OVR Shift solenoid C electrical 307
P1100 ST
—SW Starter switch circuit malfunction 309
P1101 N
—SW Neutral position switch circuit malfunction [MT vehicles] 311
P1101 N
—SW Neutral position switch circuit malfunction [AT vehicles] 315
P1102 BR Pressure sources switching solenoid valve circuit malfunction 319
P1103 TRQ Engine torque control signal circuit malfunction 325
P1104 TCS TCS signal circuit malfunction 328
P1500 FAN
—1 Radiator fan relay 1 circuit malfunction 331
P1502 FAN
—F Radiator fan function problem 338
P1700 ATTH Throttle position sensor circuit malfunction for automatic transmission 341
P1701 CRS Cruise control set signal circuit malfunction for automatic transmission 343
P1702 ATDIAG Automatic transmission diagnosis input signal circuit malfunction 346
134
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0145A
B2M0271
OBD0616
1CONNECT 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.
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F08 or F47

F08: Voltage input from mass air flow sensor is shown
on display.

F47: Mass air flow is shown on display.

F08: Is sensor output equal to or more
than 0.3 V and equal to or less than
5.0 V?

F47: Is sensor output equal to or more
than 1.3 g/sec and equal to or less
than 250 g/sec?
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 of the mass
air flow sensor.
HINT:
1Open or short circuit between mass air flow sen-
sor and ECM.

2Poor contact of connectors for mass air flow sen-
sor or ECM.
: Go to next.
: Is the value less than 0.3 V (1.3 g/sec)?
: Go to step 2.
: Go to step 5.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
138
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0172
F: DTC P0115
—ENGINE COOLANT TEMPERATURE
SENSOR CIRCUIT MALFUNCTION (TW)—
OBD0173A
DESCRIPTION:
The engine coolant temperature sensor is located on the
engine coolant pipe which is made of aluminum alloy. Its
thermistor changes resistance with respect to temperature.
A engine coolant temperature signal converted into resis-
tance is transmitted to the ECM to control the amount of
fuel injection, ignition timing, purge control solenoid valve,
etc.
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Hard to start

Erroneous idling

Poor driving performance
156
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0145A
1CONNECT 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
OBD-II general scan tool switch to ON.
4) Start engine.
OBD0176
OBD0177
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F05 or F06

F05: Water temperature is indicated in“°F”.

F06: Water temperature is indicated in“°C”.
:
Is the value greater than 300°F with func-
tion mode F05?

Is the value greater than 150°C with func-
tion mode F06?
: Go to step 2.
: Go to next.
:
Is the value less than 40°F with function
mode F05?

Is the value less than 40°C with function
mode F06?
: Go to step 3.
: Repair poor contact in connectors or harness.

Engine coolant temperature sensor connector

ECM connector

Coupling connector (B21)

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
OBD0618A
2
CHECK HARNESS.
1) Turn ignition switch to OFF.
2) Remove idle air control solenoid valve by-pass air hose.
3) Disconnect connector from engine coolant temperature
sensor.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code