LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2017 >> BRZ Limited, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics - Introduction) >> EFI system (FA20) >> Symptom table
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Symptom table

Symptom Suspected Area See
Engine does not crank (Does not start) Battery On-vehicle inspection
Starter On-vehicle inspection
Park/neutral position switch assembly(1) Adjustment
Clutch start switch assembly(2) On-vehicle inspection
Starter signal circuit Starter system (models with smart entry & start system) , Starter system (models without smart entry & start system)
No initial combustion (Does not start) ECM power source circuit ECM power supply system
Crankshaft position sensor Crankshaft position sensor (FA20)
Ignition system Circuit figure
Fuel pump control circuit Circuit figure
Fuel pump Unit inspection
Fuel injector circuit Fuel injector circuit
Valve timing Timing chain (FA20)
VC output circuit (ECM 5 V output) VC power supply circuit
VVT sensor (for intake side) DTC P0351 Ignition Coil "A" Primary/Secondary Circuit; DTC P0352 Ignition Coil "B" Primary/Secondary Circuit; DTC P0353 Ignition Coil "C" Primary/Secondary Circuit; DTC P0354 Ignition Coil "D" Primary/Secondary Circuit
VVT sensor (for exhaust side) DTC P0420 Catalyst System Efficiency Below Threshold (Bank 1)
Starter signal circuit Starter system (models with smart entry & start system) , Starter system (models without smart entry & start system)
Engine immobiliser system Description of functions
ECM Removal
Engine cranks normally but difficult to start Fuel pump control circuit Circuit figure
Fuel pump (for high pressure) Unit inspection
Fuel injector circuit Fuel injector circuit
Fuel injector assembly (for port injection) Unit inspection
Fuel injector assembly (for direct injection) Unit inspection
ECM power source circuit ECM power supply system
Starter signal circuit Starter system (models with smart entry & start system) , Starter system (models without smart entry & start system)
Engine coolant temperature sensor Installation
Intake system On-vehicle inspection
Ignition system Circuit figure
Spark plug Cam timing oil control valve ASSY (FA20)
Throttle with motor body assembly Installation
Compression Engine (FA20)
Incomplete intermittent combustion occurs (Does not start) Fuel pump control circuit Circuit figure
Fuel line Function inspection
Ignition circuit DTC P0365 Camshaft Position Sensor "B" Circuit (Bank 1); DTC P0366 Camshaft Position Sensor "B" Circuit Range/Performance (Bank 1); DTC P0390 Camshaft Position Sensor "B" Circuit (Bank 2); DTC P0391 Camshaft Position Sensor "B" Circuit Range/Performance (Bank 2)
Ignition system Circuit figure
Fuel injector circuit Fuel injector circuit
Fuel injector assembly (for port injection) Unit inspection
Fuel injector assembly (for direct injection) Unit inspection
ECM power source circuit ECM power supply system
Starter signal circuit Starter system (models with smart entry & start system) , Starter system (models without smart entry & start system)
Crankshaft position sensor Crankshaft position sensor (FA20)
VVT sensor (for intake side) DTC P0351 Ignition Coil "A" Primary/Secondary Circuit; DTC P0352 Ignition Coil "B" Primary/Secondary Circuit; DTC P0353 Ignition Coil "C" Primary/Secondary Circuit; DTC P0354 Ignition Coil "D" Primary/Secondary Circuit
VVT sensor (for exhaust side) DTC P0420 Catalyst System Efficiency Below Threshold (Bank 1)
Valve timing Timing chain (FA20)
High engine idle speed Throttle with motor body assembly Installation
Intake system On-vehicle inspection
A/C signal circuit DTC B1430/21 Room temperature sensor circuit wire break; DTC B1431/-21 Room temperature sensor circuit short-circuit
ECM power source circuit ECM power supply system
Engine coolant temperature sensor Installation
PCV valve and hose On-vehicle inspection
Low engine idle speed (Poor idling) Throttle with motor body assembly Installation
A/C signal circuit DTC B1430/21 Room temperature sensor circuit wire break; DTC B1431/-21 Room temperature sensor circuit short-circuit
Fuel pump control circuit Circuit figure
Fuel pump Unit inspection
Intake system On-vehicle inspection
PCV valve and hose On-vehicle inspection
Rough idling Compression Engine (FA20)
Ignition system Circuit figure
Spark plug Cam timing oil control valve ASSY (FA20)
Fuel injector circuit Fuel injector circuit
ECM power source circuit ECM power supply system
Fuel pump control circuit Circuit figure
Fuel injector assembly (for port injection) Unit inspection
Fuel injector assembly (for direct injection) Unit inspection
Fuel pump (for high pressure) Unit inspection
Fuel line Function inspection
Throttle with motor body assembly Installation
Intake system On-vehicle inspection
Purge valve Installation
PCV valve and hose On-vehicle inspection
Air fuel ratio sensor Installation
Heated oxygen sensor Installation
Mass air flow meter On-vehicle inspection
Knock sensor Unit inspection
Hunting (Poor idling) Throttle with motor body assembly Installation
Intake system On-vehicle inspection
PCV valve and hose On-vehicle inspection
Air fuel ratio sensor Installation
Mass air flow meter On-vehicle inspection
Hesitation/poor acceleration Fuel pump control circuit Circuit figure
Fuel pump (for high pressure) Unit inspection
Fuel line Function inspection
Spark plug Cam timing oil control valve ASSY (FA20)
Ignition system Circuit figure
Fuel injector circuit Fuel injector circuit
Fuel injector assembly (for port injection) Unit inspection
Fuel injector assembly (for direct injection) Unit inspection
ECM power source circuit ECM power supply system
Knock sensor Unit inspection
Mass air flow meter On-vehicle inspection
Throttle with motor body assembly Installation
Intake system On-vehicle inspection
Valve timing Timing chain (FA20)
Compression Engine (FA20)
Brake override system Brake override system
Surging (Poor driveability) Spark plug Cam timing oil control valve ASSY (FA20)
Fuel pump control circuit Circuit figure
Fuel pump (for high pressure) Unit inspection
Ignition system Circuit figure
Fuel injector circuit Fuel injector circuit
Fuel injector assembly (for port injection) Unit inspection
Fuel injector assembly (for direct injection) Unit inspection
ECM power source circuit ECM power supply system
Mass air flow meter On-vehicle inspection
Variable Valve Timing (VVT) system Unit inspection
Compression Engine (FA20)
Engine stalls soon after starting Fuel pump control circuit Circuit figure
Fuel pump (for high pressure) Unit inspection
Spark plug Cam timing oil control valve ASSY (FA20)
Ignition system Circuit figure
Fuel injector circuit Fuel injector circuit
Fuel injector assembly (for port injection) Unit inspection
Fuel injector assembly (for direct injection) Unit inspection
ECM power source circuit ECM power supply system
Mass air flow meter On-vehicle inspection
Variable Valve Timing (VVT) system Unit inspection
Throttle with motor body assembly Installation
Intake system On-vehicle inspection
Engine immobiliser system Description of functions
PCV valve and hose On-vehicle inspection
Compression Engine (FA20)
Engine stalls only during A/C operation A/C signal circuit DTC B1430/21 Room temperature sensor circuit wire break; DTC B1431/-21 Room temperature sensor circuit short-circuit
ECM Removal
Unable/difficult to refuel Fuel system (canister, refueling valve, roll over valve, fuel tank, etc.) -
(1) for Automatic Transmission

(2) for Manual Transmission