Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual - part 312
EN(H4DOTC)(diag)-472
General Diagnostic Table
ENGINE (DIAGNOSTICS)
*1: Check ignition coil and spark plug.
*2: Indicate the symptom occurring only in cold temperatures.
*3: Ensure secure installation.
*4: Check fuel injector, fuel pressure regulator and fuel filter.
*5: Inspect for air leak in air intake system.
6. Surging
1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Crankshaft position sensor (*3)
5) Camshaft position sensor (*3)
6) Fuel injection parts (*4)
7) Electronic throttle control
8) Fuel pump and fuel pump relay
7. Spark knock
1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor
4) Knock sensor
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay
8. After burning in exhaust system
1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Fuel injection parts (*4)
5) Fuel pump and fuel pump relay
Symptoms
Faulty parts