Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2007 Lexus RX 400h FWDFACTORY OEM SERVICE PROCEDURE
Typical Enabling Conditions
ECT sensor cold start monitor:
TYPICAL ENABLING CONDITIONS
| Monitor runs whenever following DTCs are not present | P0100 to P0103: Mass Air Flow (MAF) meter |
| Battery voltage | 10.5 V or more |
| Time after engine start | 1 second or more |
| ECT at engine start | Less than 60°C (140°F) |
| IAT sensor circuit | OK |
| Soak time | 0 seconds or more |
| Accumulated MAF | 1397 g or more |
| Fuel cut | OFF |
| Difference between ECT at engine start and IAT | Less than 40°C (72°F) |
ECT Sensor soak monitor:
TYPICAL ENABLING CONDITIONS
| Monitor runs whenever following DTCs not present | P0100 to P0103: MAF meter P0110 to P0113: IAT sensor |
| Battery voltage | 10.5 V or more |
| Engine | Running |
| Soak time | 5 hours or more |
| Either of the following conditions (a) or (b) is met | - |
| (a) ECT | 60°C (140°F) or more |
| (b) Accumulated MAF | 2921 g or more |
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.