Tech Tips
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.
| Symptom | Suspected Area | Link |
|---|---|---|
| Engine does not crank (Does not start) | Flow chart [Engine difficult to start] | |
| Flow chart [Engine difficult to start] (Vehicle Control History Code: X0810, X0811 and/or X0812) |
||
| Battery | ||
| ST relay | ||
| Starter assembly | ||
| Starter signal circuit | ||
| Smart entry and start system (for start function) | ||
| VC output circuit (ECM 5 V output) | ||
| Park/Neutral position switch assembly | ||
| No initial combustion (Does not start) | ECM power source circuit | |
| VC output circuit (ECM 5 V output) | ||
| Flow chart [Engine difficult to start] | ||
| Flow chart [Engine difficult to start] (Vehicle Control History Code: X0810, X0811 and/or X0812) |
||
| Ignition system | ||
| Fuel system | ||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| Crankshaft position sensor | ||
| Intake system | ||
| Valve timing | ||
| EGR valve assembly | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine cranks normally but difficult to start | ECM power source circuit | |
| Flow chart [Engine difficult to start] | ||
| Flow chart [Engine difficult to start] (Vehicle Control History Code: X0810, X0811 and/or X0812) |
||
| Throttle body with motor assembly | ||
| Fuel pump assembly (for high pressure side) | ||
| Fuel pump (for low pressure side) | ||
| Engine coolant temperature sensor | ||
| Fuel system | ||
| Ignition system | ||
| Spark plug | ||
| Compression | ||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| Crankshaft position sensor | ||
| Intake system | ||
| Valve timing | ||
| EGR valve assembly | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Incomplete intermittent combustion occurs (Does not start) | Flow chart [Engine difficult to start] | |
| Flow chart [Engine difficult to start] (Vehicle Control History Code: X0810, X0811 and/or X0812) |
||
| Fuel system | ||
| Ignition system | ||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| Crankshaft position sensor | ||
| Intake system | ||
| Valve timing | ||
| High engine speed | Throttle body with motor assembly | |
| ECM power source circuit | ||
| PCV system | ||
| Low engine speed (Poor idle) | Flow chart [Rough idling] | |
| Flow chart [Rough idling] (Vehicle Control History Code: X0821, X0822, X0823, X0824, X082A, X082D and/or X082E) |
||
| Fuel system | ||
| Throttle body with motor assembly | ||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| Fuel pump assembly (for high pressure side) | ||
| PCV system | ||
| Intake system | ||
| Rough idle | Flow chart [Rough idling] | |
| Flow chart [Rough idling] (Vehicle Control History Code: X0821, X0822, X0823, X0824, X082A, X082D and/or X082E) |
||
| Throttle body with motor assembly | ||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| Fuel pump assembly (for high pressure side) | ||
| Ignition system | ||
| Air fuel ratio sensor (sensor 1) | ||
| Air fuel ratio sensor (sensor 2) | ||
| Mass air flow meter sub-assembly | ||
| Manifold absolute pressure sensor | ||
| Compression | ||
| Fuel system | ||
| Spark plug | ||
| Intake system | ||
| Valve timing | ||
| EGR valve assembly | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Hunting (Poor idle) | Throttle body with motor assembly | |
| ECM power source circuit | ||
| Flow chart [Rough idling] | ||
| Flow chart [Rough idling] (Vehicle Control History Code: X0821, X0822, X0823, X0824, X082A, X082D and/or X082E) |
||
| Fuel system | ||
| Spark plug | ||
| Intake system | ||
| Drive start control system | ||
| Hesitation/Poor acceleration (Poor driveability) | Flow chart [Rough idling] | |
| Flow chart [Rough idling] (Vehicle Control History Code: X0821, X0822, X0823, X0824, X082A, X082D and/or X082E) |
||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| Fuel system | ||
| Fuel pump assembly (for high pressure side) | ||
| Ignition system | ||
| Spark plug | ||
| Intake system | ||
| Valve timing | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Brake override system | ||
| Drive start control | ||
| Lack of power | Flow chart [Lack of power] | |
| Surging (Poor driveability) | Flow chart [Rough idling] | |
| Flow chart [Rough idling] (Vehicle Control History Code: X0821, X0822, X0823, X0824, X082A, X082D and/or X082E) |
||
| Fuel system | ||
| Spark plug | ||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| No. 1 valve rocker arm sub-assembly* | ||
| Engine stalls soon after starting | Flow chart [Engine stalls] | |
| Flow chart [Engine stalls] (Vehicle Control History Code: X0800 and/or X0803) |
||
| Fuel system | ||
| Throttle body with motor assembly | ||
| Crankshaft position sensor | ||
| Ignition system | ||
| Fuel pump assembly (for high pressure side) | ||
| Intake system | ||
| Valve timing | ||
| EGR valve assembly | ||
| Engine stalls soon after slow down | Flow chart [Engine stalls] | |
| Flow chart [Engine stalls] (Vehicle Control History Code: X0800 and/or X0803) |
||
| Port fuel injector assembly | ||
| Direct fuel injector assembly | ||
| Throttle body with motor assembly | ||
| ECM | ||
| Crankshaft position sensor | ||
| Ignition system | ||
| MIL (Malfunction Indicator Lamp) malfunction | MIL Circuit | |
| Meter/Gauge system | ||
| Unable/difficult to refuel | Fuel system (canister, refueling valve, roll over valve, fuel tank, etc.) | - |
| Engine vibrates frequently when idling (Active control engine mount system) | Active control engine mount circuit |
Tech Tips
*: Check "Fuel Cut Elapsed 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.