Problem Symptoms Table [08/2023 - ]
WARNING: This page is about a different car, the 2025 Lexus RX 450h+, 2025 Lexus RX 350h, 2024 Lexus RX 450h+, 2024 Lexus RX 350h, and 2023 Lexus RX 350h. 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 | Link |
|---|---|---|
| Engine does not crank (Does not start) | Hybrid control system (for THS-HEV Model) | Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ] |
| Hybrid control system (for PHEV Model) | Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2023 - ] | |
| VC output circuit (ECM 5 V output) | Refer to VC Output Circuit [08/2023 - 10/2024] , or refer to VC Output Circuit [10/2024 - ] | |
| No initial combustion (Does not start) | ECM power source circuit | Refer to ECM Power Source Circuit [10/2022 - ] |
| VC output circuit (ECM 5 V output) | Refer to VC Output Circuit [08/2023 - 10/2024] , or refer to VC Output Circuit [10/2024 - ] | |
| Ignition system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Fuel system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Port fuel injector assembly | Refer to INSPECTION [08/2023 - ] | |
| Direct fuel injector assembly | Refer to INSPECTION [10/2022 - ] | |
| Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] | |
| Fuel pump (for low pressure side) | Refer to INSPECTION [10/2022 - ] | |
| Crankshaft position sensor | Refer to DTC P0335-11: Crankshaft Position Sensor "A" Circuit Short to Ground; DTC P0335-15: Crankshaft Position Sensor "A" Circuit Short to Battery or Open [08/2023 - ] | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Valve timing | Refer to PROCEDURE - Step 7 | |
| EGR valve assembly | Refer to INSPECTION [10/2022 - ] | |
| Engine cranks normally but difficult to start | ECM power source circuit | Refer to ECM Power Source Circuit [10/2022 - ] |
| Throttle body with motor assembly | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Fuel (engine room side) pump assembly (for high pressure side) | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Fuel pump (for low pressure side) | Refer to INSPECTION [10/2022 - ] | |
| Engine coolant temperature sensor | Refer to INSPECTION [10/2022 - ] | |
| Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] | |
| Fuel system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Ignition system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Compression | Refer to PROCEDURE - Step 9 | |
| Spark plug | Refer to PROCEDURE - Step 3 | |
| Port fuel injector assembly | Refer to INSPECTION [08/2023 - ] | |
| Direct fuel injector assembly | Refer to INSPECTION [10/2022 - ] | |
| Crankshaft position sensor | Refer to DTC P0335-11: Crankshaft Position Sensor "A" Circuit Short to Ground; DTC P0335-15: Crankshaft Position Sensor "A" Circuit Short to Battery or Open [08/2023 - ] | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Valve timing | Refer to PROCEDURE - Step 7 | |
| EGR valve assembly | Refer to INSPECTION [10/2022 - ] | |
| Incomplete intermittent combustion occurs (Does not start) | Fuel system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] |
| Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] | |
| Fuel pump (for low pressure side) | Refer to INSPECTION [10/2022 - ] | |
| Ignition system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Port fuel injector assembly | Refer to INSPECTION [08/2023 - ] | |
| Direct fuel injector assembly | Refer to INSPECTION [10/2022 - ] | |
| Crankshaft position sensor | Refer to DTC P0335-11: Crankshaft Position Sensor "A" Circuit Short to Ground; DTC P0335-15: Crankshaft Position Sensor "A" Circuit Short to Battery or Open [08/2023 - ] | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Valve timing | Refer to PROCEDURE - Step 7 | |
| High engine speed | Throttle body with motor assembly | Refer to ON-VEHICLE INSPECTION [10/2022 - ] |
| ECM power source circuit | Refer to ECM Power Source Circuit [10/2022 - ] | |
| PCV system | Refer to PROCEDURE - Step 12 | |
| Low engine speed (Poor idle) | Fuel system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] |
| Throttle body with motor assembly | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Port fuel injector assembly | Refer to INSPECTION [08/2023 - ] | |
| Direct fuel injector assembly | Refer to INSPECTION [10/2022 - ] | |
| Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] | |
| Fuel (engine room side) pump assembly (for high pressure side) | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| PCV system | Refer to PROCEDURE - Step 12 | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Rough idle | Rough idling | Refer to Rough Idling [10/2022 - ] |
| Throttle body with motor assembly | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Port fuel injector assembly | Refer to INSPECTION [08/2023 - ] | |
| Direct fuel injector assembly | Refer to INSPECTION [10/2022 - ] | |
| Fuel (engine room side) pump assembly (for high pressure side) | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Ignition system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Air fuel ratio sensor (sensor 1) | Refer to INSPECTION [10/2022 - ] | |
| Air fuel ratio sensor (sensor 2) | Refer to INSPECTION [10/2022 - ] | |
| Mass air flow meter sub-assembly | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Manifold absolute pressure sensor | Refer to DTC P0105-11: Manifold Absolute Pressure / Barometric Pressure Sensor Circuit Short to Ground [08/2023 - ] | |
| Compression | Refer to PROCEDURE - Step 9 | |
| Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] | |
| Fuel system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Valve timing | Refer to PROCEDURE - Step 7 | |
| EGR valve assembly | Refer to INSPECTION [10/2022 - ] | |
| Hunting (Poor idle) | Throttle body with motor assembly | Refer to ON-VEHICLE INSPECTION [10/2022 - ] |
| ECM power source circuit | Refer to ECM Power Source Circuit [10/2022 - ] | |
| Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] | |
| Spark plug | Refer to PROCEDURE - Step 3 | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Drive start control (for THS-HEV Model) | Refer to Drive Start Control [10/2022 - ] | |
| Drive start control (for PHEV Model) | Refer to Drive Start Control [08/2023 - ] | |
| Hesitation/Poor acceleration (Poor driveability) | Port fuel injector assembly | Refer to INSPECTION [08/2023 - ] |
| Direct fuel injector assembly | Refer to INSPECTION [10/2022 - ] | |
| Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] | |
| Fuel (engine room side) pump assembly (for high pressure side) | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Ignition system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Spark plug | Refer to PROCEDURE - Step 3 | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Valve timing | Refer to PROCEDURE - Step 7 | |
| Brake override system (for THS-HEV Model) | Refer to Brake Override System [10/2022 - ] | |
| Brake override system (for PHEV Model) | Refer to Brake Override System [08/2023 - ] | |
| Drive start control (for THS-HEV Model) | Refer to Drive Start Control [10/2022 - ] | |
| Drive start control (for PHEV Model) | Refer to Drive Start Control [08/2023 - ] | |
| Surging (Poor driveability) | Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] |
| Fuel pump (for low pressure side) | Refer to INSPECTION [10/2022 - ] | |
| Spark plug | Refer to PROCEDURE - Step 3 | |
| Port fuel injector assembly | Refer to INSPECTION [08/2023 - ] | |
| Direct fuel injector assembly | Refer to INSPECTION [10/2022 - ] | |
| Engine stalls soon after starting | Fuel pump control circuit | Refer to Fuel Pump Control Circuit [08/2023 - ] |
| Throttle body with motor assembly | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Crankshaft position sensor | Refer to DTC P0335-11: Crankshaft Position Sensor "A" Circuit Short to Ground; DTC P0335-15: Crankshaft Position Sensor "A" Circuit Short to Battery or Open [08/2023 - ] | |
| Ignition system | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Fuel (engine room side) pump assembly (for high pressure side) | Refer to ON-VEHICLE INSPECTION [08/2023 - ] | |
| Intake system | Refer to ON-VEHICLE INSPECTION [10/2022 - ] | |
| Valve timing | Refer to PROCEDURE - Step 7 | |
| EGR valve assembly | Refer to INSPECTION [10/2022 - ] | |
| MIL (Malfunction Indicator Lamp) malfunction | MIL Circuit | Refer to MIL Circuit [10/2022 - ] |
| Meter/gauge system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ] | |
| Unable/difficult to refuel | Fuel system (canister, refueling valve, roll over valve, fuel tank, etc.) | - |