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Home >> Toyota >> 2021 >> 4Runner TRD Pro >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostics - Introduction (1 Of 2) >> SFI System >> Problem Symptoms Table [08/2015 - 08/2019] >> Problem Symptoms Table [08/2015 - 08/2019]
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Problem Symptoms Table [08/2015 - 08/2019]

HINT: 

SFI SYSTEM

Symptom Suspected Area See
Engine does not crank (Does not start) Battery Refer to PROCEDURE - Step 1
Starter relay (ST) Refer to PROCEDURE - Step 1
Starter assembly Refer to INSPECTION [08/2015 - ]
Start signal circuit Refer to Starter Signal Circuit [08/2015 - 12/2016] , or refer to Starter Signal Circuit [12/2016 - 08/2019]
VC output circuit Refer to VC Output Circuit [08/2015 - 08/2019]
Park/neutral position switch (for 2WD) Refer to INSPECTION [08/2015 - ]
Park/neutral position switch (for 4WD) Refer to INSPECTION [08/2015 - ]
No initial combustion (Does not start) Immobilizer system (w/ Smart Key System) Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - 08/2019]
Immobilizer system (w/o Smart Key System) Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - 08/2019]
ECM power source circuit Refer to ECM Power Source Circuit [08/2015 - 08/2019]
VC output circuit Refer to VC Output Circuit [08/2015 - 08/2019]
Ignition system Refer to PROCEDURE - Step 1
Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Fuel injector assembly Refer to INSPECTION [08/2015 - ]
Crankshaft position sensor Refer to INSPECTION [08/2015 - ]
Intake system Refer to PROCEDURE - Step 1
Valve timing Refer to PROCEDURE - Step 4
No. 1 valve rocker arm sub-assembly* Refer to REMOVAL [08/2015 - ]
Engine cranks normally but difficult to start ECM power source circuit Refer to ECM Power Source Circuit [08/2015 - 08/2019]
Engine difficult to start Refer to Engine Difficult to Start [08/2015 - 08/2019]
Throttle body with motor assembly Refer to INSPECTION [08/2015 - ]
Fuel pump Refer to INSPECTION [08/2015 - ]
Engine coolant temperature sensor Refer to INSPECTION [08/2015 - ]
Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Ignition system Refer to PROCEDURE - Step 1
Spark plug Refer to PROCEDURE - Step 2
Compression Refer to PROCEDURE - Step 3
Fuel injector assembly Refer to INSPECTION [08/2015 - ]
Crankshaft position sensor Refer to INSPECTION [08/2015 - ]
Intake system Refer to PROCEDURE - Step 1
Valve timing Refer to PROCEDURE - Step 4
No. 1 valve rocker arm sub-assembly* Refer to REMOVAL [08/2015 - ]
Incomplete intermittent combustion occurs (Does not start) Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Ignition system Refer to PROCEDURE - Step 1
Fuel injector assembly Refer to INSPECTION [08/2015 - ]
Crankshaft position sensor Refer to INSPECTION [08/2015 - ]
Intake system Refer to PROCEDURE - Step 1
Valve timing Refer to PROCEDURE - Step 4
High engine speed Throttle body with motor assembly Refer to INSPECTION [08/2015 - ]
ECM power source circuit Refer to ECM Power Source Circuit [08/2015 - 08/2019]
PCV hose Refer to COMPONENTS [08/2015 - ]
PCV valve Refer to INSPECTION [08/2015 - ]
Low engine speed (Poor idle) Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Throttle body with motor assembly Refer to INSPECTION [08/2015 - ]
Fuel injector assembly Refer to INSPECTION [08/2015 - ]
Fuel pump Refer to INSPECTION [08/2015 - ]
PCV hose Refer to COMPONENTS [08/2015 - ]
PCV valve Refer to INSPECTION [08/2015 - ]
Intake system Refer to PROCEDURE - Step 1
Rough idle Rough idling Refer to Rough Idling [08/2015 - 08/2019]
Throttle body with motor assembly Refer to INSPECTION [08/2015 - ]
Fuel injector assembly Refer to INSPECTION [08/2015 - ]
Fuel pump Refer to INSPECTION [08/2015 - ]
Ignition system Refer to PROCEDURE - Step 1
Compression Refer to PROCEDURE - Step 3
Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Spark plug Refer to PROCEDURE - Step 2
Intake system Refer to PROCEDURE - Step 1
Valve timing Refer to PROCEDURE - Step 4
No. 1 valve rocker arm sub-assembly* Refer to REMOVAL [08/2015 - ]
Hunting (Poor idle) Throttle body with motor assembly Refer to INSPECTION [08/2015 - ]
ECM power source circuit Refer to ECM Power Source Circuit [08/2015 - 08/2019]
Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Spark plug Refer to PROCEDURE - Step 2
Intake system Refer to PROCEDURE - Step 1
Hesitation/Poor acceleration (Poor driveability) Fuel injector assembly Refer to INSPECTION [08/2015 - ]
Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Fuel pump Refer to INSPECTION [08/2015 - ]
Ignition system Refer to PROCEDURE - Step 1
Spark plug Refer to PROCEDURE - Step 2
Intake system Refer to PROCEDURE - Step 1
Valve timing Refer to PROCEDURE - Step 4
No. 1 valve rocker arm sub-assembly* Refer to REMOVAL [08/2015 - ]
Brake override system Refer to Brake Override System [08/2015 - 08/2019]
Lack of power Lack of power Refer to Lack of Power [08/2015 - 08/2019]
Surging (Poor driveability) Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Spark plug Refer to PROCEDURE - Step 2
Fuel injector assembly Refer to INSPECTION [08/2015 - ]
No. 1 valve rocker arm sub-assembly* Refer to REMOVAL [08/2015 - ]
Engine stalls soon after starting Engine stalls Refer to Engine Stalls [08/2015 - 08/2019]
Fuel pump control circuit Refer to Fuel Pump Control Circuit [08/2015 - 08/2019]
Throttle body with motor assembly Refer to INSPECTION [08/2015 - ]
Crankshaft position sensor Refer to INSPECTION [08/2015 - ]
Ignition system Refer to PROCEDURE - Step 1
Fuel pump Refer to INSPECTION [08/2015 - ]
Intake system Refer to PROCEDURE - Step 1
Valve timing Refer to PROCEDURE - Step 4
Engine stalls soon after slow down Engine stalls Refer to Engine Stalls [08/2015 - 08/2019]
Fuel injector assembly Refer to INSPECTION [08/2015 - ]
Throttle body with motor assembly Refer to INSPECTION [08/2015 - ]
ECM Refer to TERMINALS OF ECM [08/2015 - 08/2019] 
Crankshaft position sensor Refer to INSPECTION [08/2015 - ]
Ignition system Refer to PROCEDURE - Step 1
Unable/difficult to refuel Fuel system (canister, roll-over valve, fuel tank, etc.) -

HINT: 

*: Check "Fuel Cut Elps Time" in the Data List. If the elapsed time is over 0 sec, then the engine speed is high (the engine speed at which fuel cut occurs + 500 rpm or more). In this situation, there is a possibility that a No. 1 valve rocker arm sub-assembly will become loose and malfunction, check that the No. 1 valve rocker arm sub-assemblies are properly installed.