LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2018 >> BRZ tS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics - Introduction) >> DTC Table >> Symptom Table
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Symptom Table

Symptom Suspected Area
Engine does not crank (Does not start) Battery
Starter
Park/neutral position switch assembly(1)
Clutch start switch assembly(2)
Starter signal circuit
No initial combustion (Does not start) ECM power source circuit
Crankshaft position sensor
Ignition system
Fuel pump control circuit
Fuel pump
Fuel injector circuit
Valve timing
VC output circuit (ECM 5 V output)
VVT sensor (for intake side)
VVT sensor (for exhaust side)
Starter signal circuit
Engine immobiliser system
ECM
Engine cranks normally but difficult to start Fuel pump control circuit
Fuel pump (for high pressure)
Fuel injector circuit
Fuel injector assembly (for port injection)
Fuel injector assembly (for direct injection)
ECM power source circuit
Starter signal circuit
Engine coolant temperature sensor
Intake system
Ignition system
Spark plug
Throttle with motor body assembly
Compression
Incomplete intermittent combustion occurs (Does not start) Fuel pump control circuit
Fuel line
Ignition circuit
Ignition system
Fuel injector circuit
Fuel injector assembly (for port injection)
Fuel injector assembly (for direct injection)
ECM power source circuit
Starter signal circuit
Crankshaft position sensor
VVT sensor (for intake side)
VVT sensor (for exhaust side)
Valve timing
High engine idle speed Throttle with motor body assembly
Intake system
A/C signal circuit
ECM power source circuit
Engine coolant temperature sensor
PCV valve and hose
Low engine idle speed (Poor idling) Throttle with motor body assembly
A/C signal circuit
Fuel pump control circuit
Fuel pump
Intake system
PCV valve and hose
Rough idling Compression
Ignition system
Spark plug
Fuel injector circuit
ECM power source circuit
Fuel pump control circuit
Fuel injector assembly (for port injection)
Fuel injector assembly (for direct injection)
Fuel pump (for high pressure)
Fuel line
Throttle with motor body assembly
Intake system
Purge valve
PCV valve and hose
Air fuel ratio sensor
Heated oxygen sensor
Mass air flow meter
Knock sensor
Hunting (Poor idling) Throttle with motor body assembly
Intake system
PCV valve and hose
Air fuel ratio sensor
Mass air flow meter
Hesitation/poor acceleration Fuel pump control circuit
Fuel pump (for high pressure)
Fuel line
Spark plug
Ignition system
Fuel injector circuit
Fuel injector assembly (for port injection)
Fuel injector assembly (for direct injection)
ECM power source circuit
Knock sensor
Mass air flow meter
Throttle with motor body assembly
Intake system
Valve timing
Compression
Brake override system
Surging (Poor driveability) Spark plug
Fuel pump control circuit
Fuel pump (for high pressure)
Ignition system
Fuel injector circuit
Fuel injector assembly (for port injection)
Fuel injector assembly (for direct injection)
ECM power source circuit
Mass air flow meter
Variable Valve Timing (VVT) system
Compression
Engine stalls soon after starting Fuel pump control circuit
Fuel pump (for high pressure)
Spark plug
Ignition system
Fuel injector circuit
Fuel injector assembly (for port injection)
Fuel injector assembly (for direct injection)
ECM power source circuit
Mass air flow meter
Variable Valve Timing (VVT) system
Throttle with motor body assembly
Intake system
Engine immobiliser system
PCV valve and hose
Compression
Engine stalls only during A/C operation A/C signal circuit
ECM
Unable/difficult to refuel Fuel system (canister, refueling valve, roll over valve, fuel tank, etc.)
(1) for Automatic Transmission

(2) for Manual Transmission