1996 SUBARU LEGACY sensor

8. Diagnostics for Engine Starting
Failure
A: BASIC DIAGNOSTICS CHART
Inspection of starter motor circuit.
Inspection of ECM power supply and ground line.
Inspection of ignition control system.
Inspection of fuel pump circuit.
Inspection of fuel injector circuit.
Inspection of crankshaft position sensor circuit.
Inspection of camshaft position sensor circuit.
Inspection using Subaru select monitor or OBD-II general
scan tool or inspection using“9. General Diagnostics Table
2-7 [T900]”.







88
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

G: CRANKSHAFT POSITION SENSOR
CIRCUIT
8G1Check harness between ECM and crankshaft
position sensor connector.
8G2Check crankshaft position sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:
B2M0529
NOTE:
For the diagnostic procedure on crankshaft position sensor
circuit, refer to 2-7 [T10AB0].

111
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

H: CAMSHAFT POSITION SENSOR CIRCUIT
8H1Check harness between ECM and camshaft
position sensor connector.
8H2Check camshaft position sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:
B2M0530
NOTE:
For the diagnostic procedure on camshaft position sensor
circuit, refer to 2-7 [T10AC0].

11 2
2-7ON-BOARD DIAGNOSTICS II SYSTEM
8. Diagnostics for Engine Starting Failure

9. General Diagnostics Table
1. FOR ENGINE
12345678910111213
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 ignitor, 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 or 2-3b of
the Service Manual.
11 8
2-7ON-BOARD DIAGNOSTICS II SYSTEM
9. 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.  
1234567891011121314151617181920212223242526272829
11 9
2-7ON-BOARD DIAGNOSTICS II SYSTEM
9. 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. 
1234567891011121314151617181920212223242526272829
121
2-7ON-BOARD DIAGNOSTICS II SYSTEM
9. General Diagnostics Table

10. 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 125
P0101 QA
—R Mass air flow sensor circuit range/performance problem 132
P0105 P
—S Pressure sensor circuit malfunction 134
P0106 PS
—R Pressure sensor circuit range/performance problem 142
P0115 TW Engine coolant temperature sensor circuit malfunction 147
P0120 THV Throttle position sensor circuit malfunction 151
P0121 TH
—R Throttle position sensor circuit range/performance problem 157
P0125 TW
—CL Insufficient coolant temperature for closed loop fuel control 159
P0130 FO2
—V Front oxygen sensor circuit malfunction 161
P0133 FO2
—R Front oxygen sensor circuit slow response 164
P0135 FO2H Front oxygen sensor heater circuit malfunction 166
P0136 RO2
—V Rear oxygen sensor circuit malfunction 172
P0139 RO2
—R Rear oxygen sensor circuit slow response 177
P0141 RO2H Rear oxygen sensor heater circuit malfunction 179
P0170 FUEL Fuel trim malfunction 185
P0180 TNKT Fuel temperature sensor A circuit malfunction 190
P0181 TNKT
—F Fuel temperature sensor A circuit range/performance problem 195
P0201 INJ1 Fuel injector circuit malfunction - #1
197 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
203 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 211
P0335 CRANK Crankshaft position sensor circuit malfunction 215
P0340 CAM Camshaft position sensor circuit malfunction 218
P0400 EGR Exhaust gas recirculation flow malfunction 221
P0403 EGRSOL Exhaust gas recirculation circuit malfunction 227
P0420 CAT Catalyst system efficiency below threshold 233
P0440 EVAP Evaporative emission control system malfunction 236
P0441 CPC
—F Evaporative emission control system incorrect purge flow 241
P0443 CPC Evaporative emission control system purge control valve circuit malfunction 244
P0446 VCMSOL Evaporative emission control system vent control malfunction 249
P0450 TNKP Evaporative emission control system pressure sensor malfunction 255
P0451 TNKP
—F Evaporative emission control system pressure sensor range/performance problem 264
123
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

DTC
No.Abbreviation
(Subaru select monitor)Item Page
P0500 VSP Vehicle speed sensor malfunction 266
P0505 ISC Idle control system malfunction 269
P0506 ISC
—L Idle control system RPM lower than expected 276
P0507 ISC
—H Idle control system RPM higher than expected 277
P0600—Serial communication link malfunction 278
P0601 RAM Internal control module memory check sum error 281
P0703 ATBRK Brake switch input malfunction 283
P0705 ATRNG Transmission range sensor circuit malfunction 286
P0710 ATF Transmission fluid temperature sensor circuit malfunction 293
P0720 ATVSP Output speed sensor (vehicle speed sensor 1) circuit malfunction 294
P0725 ATNE Engine speed input circuit malfunction 295
P0731 ATGR1 Gear 1 incorrect ratio
296 P0732 ATGR2 Gear 2 incorrect ratio
P0733 ATGR3 Gear 3 incorrect ratio
P0734 ATGR4 Gear 4 incorrect ratio
P0740 ATLU
—F Torque converter clutch system malfunction 300
P0743 ATLU Torque converter clutch system electrical 304
P0748 ATPL Pressure control solenoid electrical 305
P0753 ATSFT1 Shift solenoid A electrical 306
P0758 ATSFT2 Shift solenoid B electrical 307
P0760 ATOVR
—F Shift solenoid C malfunction 308
P0763 ATOVR Shift solenoid C electrical 312
P1100 ST
—SW Starter switch circuit malfunction 313
P1101 N/P
—SW Neutral position switch circuit malfunction [MT vehicles] 315
P1101 N/P
—SW Neutral position switch circuit malfunction [AT vehicles] 318
P1102 BR Pressure sources switching solenoid valve circuit malfunction 322
P1103 TRQ Engine torque control signal circuit malfunction 328
P1400 PCVSOL Fuel tank pressure control solenoid valve circuit malfunction 331
P1401 PCV
—F Fuel tank pressure control system function problem 337
P1402 FLVL Fuel level sensor circuit malfunction 339
P1500 FAN
—1 Radiator fan relay 1 circuit malfunction 351
P1502 FAN
—F Radiator fan function problem 358
P1700 ATTH Throttle position sensor circuit malfunction for automatic transmission 361
P1701 ATCRS Cruise control set signal circuit malfunction for automatic transmission 362
P1702 ATDIAG Automatic transmission diagnosis input signal circuit malfunction 365
P0461*1 EXERR22 Fuel level sensor circuit range/performance problem 368
*1: Only OBD-II general scan tool displays DTC.
124
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code