Subaru Legacy III (2000-2003 year). Manual - part 173
EN(H4SO)-304
ENGINE (DIAGNOSTICS)
GENERAL DIAGNOSTIC TABLE
20.General Diagnostic Table
A: INSPECTION
1. ENGINE
NOTE:
Malfunction of parts other than those listed is also possible. <Ref. to ME(H4SO)-89, Engine Trouble in Gen-
eral.>
Symptom
Problem parts
1. Engine stalls during idling.
1) Idle air control solenoid valve
2) Intake manifold pressure sensor
3) Intake air temperature sensor
4) Intake air temperature and pressure sensor
5) Ignition parts (*1)
6) Engine coolant temperature sensor (*2)
7) Crankshaft position sensor (*3)
8) Camshaft position sensor (*3)
9) Fuel injection parts (*4)
2. Rough idling
1) Idle air control solenoid valve
2) Intake manifold pressure sensor
3) Intake air temperature sensor
4) Intake air temperature and pressure sensor
5) Engine coolant temperature sensor (*2)
6) Ignition parts (*1)
7) Air intake system (*5)
8) Fuel injection parts (*4)
9) Throttle position sensor
10) Crankshaft position sensor (*3)
11) Camshaft position sensor (*3)
12) Oxygen sensor
13) Fuel pump and fuel pump relay
3. Engine does not return to idle.
1) Idle air control solenoid valve
2) Engine coolant temperature sensor
3) Accelerator cable (*6)
4) Throttle position sensor
5) Intake manifold pressure sensor
6) Intake air temperature sensor
7) Intake air temperature and pressure sensor
4. Poor acceleration
1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Intake air temperature and pressure sensor
4) Throttle position sensor
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay
7) Engine coolant temperature sensor (*2)
8) Crankshaft position sensor (*3)
9) Camshaft position sensor (*3)
10) A/C switch and A/C cut relay
11) Engine torque control signal circuit
12) Ignition parts (*1)
5. Engine stalls or engine sags or hesitates at
acceleration.
1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Intake air temperature and pressure sensor
4) Engine coolant temperature sensor (*2)
5) Crankshaft position sensor (*3)
6) Camshaft position sensor (*3)
7) Purge control solenoid valve
8) Fuel injection parts (*4)
9) Throttle position sensor
10) Fuel pump and fuel pump relay