1996 SUBARU LEGACY check oil

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

WIRING DIAGRAM:

RHD Model
B2M0787
10J1CHECK 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 step10J2.
OBD0145A
10J2
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.
162
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

: Has the vehicle been run empty of fuel?
: Finish diagnostics operation, if the engine has no
abnormality.
: Go to next.
: Was the cause of misfire diagnosed when
the engine is running?
NOTE:
Ex. Remove spark plug cord, etc.
: Finish diagnostics operation, if the engine has no
abnormality.
: Repair connector.
NOTE:
In this case, repair the following:

Poor contact in ignitor connector

Poor contact in ignition coil connector

Poor contact in fuel injector connector on faulty cylinders

Poor contact in ECM connector

Poor contact in coupling connector (B22)
10Z3
CHECK AIR INTAKE SYSTEM.
: Is there a fault in air intake system?
NOTE:
Check the following items:

Are there air leaks or air suction caused by loose or dis-
located nuts and bolts?

Are there cracks or any disconnection of hoses?
: Repair air intake system.
: Go to step10Z4.
OBD0145A
10Z4
CHECK MISFIRE SYMPTOM.
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) Turn ignition switch to ON, and turn Subaru Select
Monitor or OBD-II general scan tool switch to ON.
207
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

G3M0152
4) Read diagnostic trouble code (DTC).

Subaru Select Monitor
Designate mode use function key.
Function mode: FB1

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Operation Manual.
NOTE:
Perform diagnosis according to the items listed below.
DTC Next action
Only one cylinder Go to step
1.
P0301 and P0302 Go to step
2.
P0303 and P0304 Go to step
3.
P0301 and P0303 Go to step
4.
P0302 and P0304 Go to step
5.
Others Go to step
6.
1ONLY ONE CYLINDER
: Is there a fault in that cylinder?
NOTE:
Check the following items.

Spark plug

Spark plug cord

Fuel injector

Compression ratio
: Go to next.
: Go to DTC P0170, 2-7 [T10P3], [T10P4] and
[T10P5].

2GROUP OF #1 AND #2 CYLINDERS
: Are there faults in #1 and #2 cylinders?
NOTE:
Check the following items.

Spark plugs

Fuel injectors

Ignition coil
: Go to next.
: Go to DTC P0170, 2-7 [T10P3], [T10P4] and
[T10P5].
NOTE:
If no abnormal is discovered, check for“8. F: IGNITION
SYSTEM”of #1 and #2 cylinders side.
208
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

3GROUP OF #3 AND #4 CYLINDERS
: Are there faults in #3 and #4 cylinders?
NOTE:
Check the following items.

Spark plugs

Fuel injectors

Ignition coil
: Go to next.
: Go to DTC P0170, 2-7 [T10P3], [T10P4] and
[T10P5].
NOTE:
If no abnormal is discovered, check for“8. F: IGNITION
SYSTEM”of #3 and #4 cylinders side.

4GROUP OF #1 AND #3 CYLINDERS
: Are there faults in #1 and #3 cylinders?
NOTE:
Check the following items.

Spark plugs

Fuel injectors

Skipping timing belt teeth
: Go to next.
: Go to DTC P0170, 2-7 [T10P3], [T10P4] and
[T10P5].

5GROUP OF #2 AND #4 CYLINDERS
: Are there faults in #2 and #4 cylinders?
NOTE:
Check the following items.

Spark plugs

Fuel injectors

Skipping timing belt teeth
: Go to next.
: Go to DTC P0170, 2-7 [T10P3], [T10P4] and
[T10P5].

6THE CYLINDER AT RANDOM
: Is the engine idle rough?
: Go to next.
: Go to DTC P0170, 2-7 [T10P3], [T10P4] and
[T10P5].
209
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

OBD0404
AW: DTC P0725
—ENGINE SPEED INPUT CIRCUIT
MALFUNCTION (ATNE)—
DTC DETECTING CONDITION:

Two consecutive trips with fault
TROUBLE SYMPTOM:

No lock-up (after engine warm-up)

AT diagnostic indicator light (AT OIL TEMP indicator
light) remains on when vehicle speed is“0”.
10AW1Check DTC P0725 on display.
Check engine speed input signal circuit.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:
B2M0585
10AW1
CHECK DTC P0725 ON DISPLAY.
: Does the Subaru select monitor or OBD-II
general scan tool indicate DTC P0725?
: Check engine speed input signal circuit.
NOTE:
For the diagnostic procedure on engine speed input circuit,
refer to 3-2 [T7H0].

295
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

G3M0717
3. OPERATION OF SHIFT SELECTOR LEVER
WARNING:
Stop the engine while checking operation of selector
lever.
1) Check that selector lever does not move from“N”to“R”
without pushing the button.
2) Check that selector lever does not move from“R”to“P”
without pushing the button.
3) Check that selector lever does not move from“P”to“R”
without pushing the button.
4) Check that selector lever does not move from“3”to“2”
without pushing the button.
3. Electrical Components Location
1. SENSOR AND CONTROL MODULE
B3M0178B
1Throttle position sensor

2Dropping resistor

3Vehicle speed sensor 2

4Inhibitor switch

5ECM

6Vehicle speed sensor 1 (AWD)

7Vehicle speed sensor 1 (FWD)

8TCM
9Data link connector (for Subaru select monitor only)

10Data link connector (for Subaru select monitor and OBD-II
general scan tool)

11Diagnosis connector

12Diagnosis terminal

13AT OIL TEMP indicator light
(AT diagnostic indicator light)
3
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
2. Pre-inspection - 3. Electrical Components Location

G3M0717
3. OPERATION OF SHIFT SELECTOR LEVER
WARNING:
Stop the engine while checking operation of selector
lever.
1) Check that selector lever does not move from“N”to“R”
without pushing the button.
2) Check that selector lever does not move from“R”to“P”
without pushing the button.
3) Check that selector lever does not move from“P”to“R”
without pushing the button.
4) Check that selector lever does not move from“3”to“2”
without pushing the button.
3. Electrical Components Location
1. SENSOR AND CONTROL MODULE
B3M0178B
1Throttle position sensor

2Dropping resistor

3Vehicle speed sensor 2

4Inhibitor switch

5ECM

6Vehicle speed sensor 1 (AWD)

7Vehicle speed sensor 1 (FWD)

8TCM
9Data link connector (for Subaru select monitor only)

10Data link connector (for Subaru select monitor and OBD-II
general scan tool)

11Diagnosis connector

12Diagnosis terminal

13AT OIL TEMP indicator light
(AT diagnostic indicator light)
3
3-2AUTOMATIC TRANSMISSION AND DIFFERENTIAL
2. Pre-inspection - 3. Electrical Components Location