Contents Wiring diagrams Section: Testing & Diagnostics All sections

DTC U0422 CAN (BCU) DATA ABNORMAL Subaru Outback BR

Note. For the diagnostic procedure, refer to LAN article. Ref. to BASIC DIAGNOSTIC PROCEDURE .

Note. Malfunction of parts other than those listed is also possible. Ref. to ENGINE TROUBLE IN GENERAL .

SymptomsProblem parts
1. Engine stalls during idling.Manifold absolute pressure sensor Mass air flow and intake air temperature sensor Ignition parts ( (1) ) Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Fuel injection parts ( (4) ) Electronic throttle control
2. Rough idlingManifold absolute pressure sensor Mass air flow and intake air temperature sensor Engine coolant temperature sensor ( (2) ) Ignition parts ( (1) ) Air intake system ( (5) ) Fuel injection parts ( (4) ) Electronic throttle control Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Oxygen sensor Fuel pump and fuel pump relay EGR valve Oil switching solenoid valve
3. Engine does not return to idle.Engine coolant temperature sensor Electronic throttle control Manifold absolute pressure sensor Mass air flow and intake air temperature sensor EGR valve Accelerator pedal position sensor Oil temperature sensor
4. Poor accelerationManifold absolute pressure sensor Mass air flow and intake air temperature sensor Electronic throttle control Fuel injection parts ( (4) ) Fuel pump and fuel pump relay Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Engine torque control signal circuit Ignition parts ( (1) ) EGR valve Accelerator pedal position sensor Oil temperature sensor Oil switching solenoid valve
5. Engine stalls, hesitates, or sputters at acceleration.Manifold absolute pressure sensor Mass air flow and intake air temperature sensor Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Purge control solenoid valve Fuel injection parts ( (4) ) Electronic throttle control Fuel pump and fuel pump relay EGR valve
6. SurgingMass air flow and intake air temperature sensor Manifold absolute pressure sensor Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Fuel injection parts ( (4) ) Electronic throttle control Fuel pump and fuel pump relay EGR valve
7. Spark knockMass air flow and intake air temperature sensor Manifold absolute pressure sensor Engine coolant temperature sensor Knock sensor Fuel injection parts ( (4) ) Fuel pump and fuel pump relay EGR valve Oil switching solenoid valve
8. After-burning in exhaust systemMass air flow and intake air temperature sensor Manifold absolute pressure sensor Engine coolant temperature sensor ( (2) ) Fuel injection parts ( (4) ) Fuel pump and fuel pump relay
(1) Check ignition coil and spark plug. (2) Indicate the symptom occurring only in cold temperatures. (3) Ensure the secure installation. (4) Check fuel injector, fuel pressure regulator and fuel filter. (5) Inspect air leak in air intake system.
(1)Check ignition coil and spark plug.
(2)Indicate the symptom occurring only in cold temperatures.
(3)Ensure the secure installation.
(4)Check fuel injector, fuel pressure regulator and fuel filter.
(5)Inspect air leak in air intake system.

PROBLEM SYMPTOMS REFERENCE CHART