Problem Symptoms Table [08/2013 - ]

WARNING: This page is about a different car, the 2015 Lexus IS 350C and 2014 Lexus IS 350C. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.

SFI SYSTEM

Symptom	Suspected Area	Refer To
Engine does not crank (Does not start)	Immobilizer system	Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2013 - ]
	Battery	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	VC output circuit (ECM 5 V output)	Refer to VC Output Circuit [08/2013 - ]
	Cranking holding function circuit	Refer to Cranking Holding Function Circuit [08/2013 - ]
	Smart access system with push button	Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2013 - ]
	Starter assembly	Refer to INSPECTION [08/2013 - ]
No initial combustion (Does not start)	ECM power source circuit	Refer to ECM Power Source Circuit [08/2013 - ]
	VC output circuit (ECM 5 V output)	Refer to VC Output Circuit [08/2013 - ]
	Crankshaft position sensor	Refer to INSPECTION [08/2013 - ]
	Fuel pump control circuit	Refer to Fuel Pump Control Circuit [08/2013 - ]
	Ignition system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Valve timing	Refer to PROCEDURE - Step 4
Engine cranks normally but difficult to start	Fuel pump control circuit	Refer to Fuel Pump Control Circuit [08/2013 - ]
	Fuel pump for high pressure	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Engine coolant temperature sensor	Refer to INSPECTION [08/2013 - ]
	Ignition system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Fuel injector assembly (for port injection)	Refer to INSPECTION [08/2013 - ]
	Fuel injector assembly (for direct injection)	Refer to INSPECTION [08/2013 - ]
	Compression	Refer to ON-VEHICLE INSPECTION [08/2013 - ] - Step 10
	Intake system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Throttle body assembly	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	ECM power source circuit	Refer to ECM Power Source Circuit [08/2013 - ]
Incomplete intermittent combustion occurs (Does not start)	Fuel pump control circuit	Refer to Fuel Pump Control Circuit [08/2013 - ]
	Ignition system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Fuel line	Refer to SYSTEM DIAGRAM [08/2013 - ]
	Fuel injector assembly (for port injection)	Refer to INSPECTION [08/2013 - ]
	Fuel injector assembly (for direct injection)	Refer to INSPECTION [08/2013 - ]
	Crankshaft position sensor	Refer to INSPECTION [08/2013 - ]
High engine speed (Poor idle)	Air conditioning signal circuit	-
	Throttle body assembly	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Engine coolant temperature sensor	Refer to INSPECTION [08/2013 - ]
	PCV hose	Refer to ON-VEHICLE INSPECTION [08/2013 - ] - Step 2
	PCV system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
Low engine speed (Poor idle)	Fuel pump control circuit	Refer to Fuel Pump Control Circuit [08/2013 - ]
	Fuel pump for high pressure	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Throttle body assembly control	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Intake system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	PCV hose	Refer to ON-VEHICLE INSPECTION [08/2013 - ] - Step 2
Rough idle	Compression (engine mechanical)	Refer to ON-VEHICLE INSPECTION [08/2013 - ] - Step 10
	Air fuel ratio sensor	Refer to INSPECTION [08/2013 - ]
	Heated oxygen sensor	Refer to INSPECTION [08/2013 - ]
	Mass air flow meter	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Ignition system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Air conditioning signal circuit	-
	Fuel line	Refer to SYSTEM DIAGRAM [08/2013 - ]
	Fuel pump for low pressure	Refer to INSPECTION [08/2013 - ]
	Fuel pump for high pressure	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Intake system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Throttle control system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	PCV hose	Refer to ON-VEHICLE INSPECTION [08/2013 - ] - Step 2
Hunting (Poor idle)	PCV hose	Refer to ON-VEHICLE INSPECTION [08/2013 - ] - Step 2
	Mass air flow meter	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Air fuel ratio sensor	Refer to INSPECTION [08/2013 - ]
Hesitation/Poor acceleration (Poor driveability)	Fuel line	Refer to SYSTEM DIAGRAM [08/2013 - ]
	Fuel pump for low pressure	Refer to INSPECTION [08/2013 - ]
	Fuel pump for high pressure	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Mass air flow meter	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Throttle body assembly	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Knock control sensor	Refer to INSPECTION [08/2013 - ]
	Air intake control circuit	-
	Brake override system	Refer to Brake Override System [08/2013 - ]
Surging (Poor driveability)	Fuel line	Refer to SYSTEM DIAGRAM [08/2013 - ]
	Fuel pump control circuit	Refer to Fuel Pump Control Circuit [08/2013 - ]
	Fuel pump for high pressure	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Ignition system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Fuel injector for port injection	Refer to INSPECTION [08/2013 - ]
	Fuel injector for direct injection	Refer to INSPECTION [08/2013 - ]
Engine stalls soon after starting	Mass air flow meter	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Intake system	Refer to ON-VEHICLE INSPECTION [08/2013 - ]
	Fuel line	Refer to SYSTEM DIAGRAM [08/2013 - ]
Unable/difficult to refuel	Fuel system (canister, refueling valve, roll over valve, fuel tank, etc.)	-