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.
2001 Lexus ES 300FACTORY OEM SERVICE PROCEDURE
Engine Controls - Self-Diagnostics
- Introduction
- Self-Diagnostic System
- Scan Tool Problems
- Summary
- Diagnostic Tests
- Notes
- DTC P0100: Mass Airflow (MAF) Sensor Circuit Fault
- DTC P0101: Mass Airflow (MAF) Sensor Circuit Range/Performance Fault
- DTC P0110: Intake Air Temperature (IAT) Sensor Circuit
- DTC P0115: Engine Coolant Temperature (ECT) Sensor Circuit
- DTC P0116: Engine Coolant Temperature (ECT) Sensor Circuit Range/Performance Fault
- DTC P0120: Throttle Position (TP) Sensor Circuit Malfunction
- DTC P0121: Throttle Position (TP) Sensor Circuit Range/Performance Fault
- DTC P0125: Insufficient Coolant Temperature For Closed Loop Fuel Control
- DTC P0128: Thermostat Fault
- DTC P0136: Heated Oxygen Sensor Circuit
- DTC P0141: Heated Oxygen Sensor Heater Circuit
- DTC P0171 Or P0172: System Too Lean/Rich (Bank No. 1) Or DTC P0174 Or P0175: System Too Lean/Rich (Bank No. 2)
- DTC P0300: Random Cylinder Misfire Detected
- DTC P0301-P0306: Cylinders No. 1-6 Misfire Detected
- DTC P0325: Knock Sensor Circuit No. 1 Malfunction Or DTC P0330: Knock Sensor Circuit No. 2 Malfunction
- DTC P0335 Or P1335: Crankshaft Position (CKP) Sensor Circuit
- DTC P0340: Variable Valve Timing (VVT) Sensor Circuit
- DTC P0420: Catalyst System Efficiency Below Threshold
- DTC P0440: EVAP System Malfunction Or DTC P0442: EVAP System Leak Detected (Small Leak)
- DTC P0441: Incorrect EVAP Purge Flow Or DTC P0446: EVAP Vent Control Fault
- DTC P0450: EVAP Pressure Sensor Malfunction Or DTC P0451: EVAP Pressure Sensor Range/Performance Fault
- DTC P0500: Vehicle Speed Sensor (VSS) Malfunction
- DTC P0505: Idle Control System Malfunction
- DTC P1130 Or P1150: Air/Fuel Sensor Circuit Range/Performance Fault
- DTC P1133 Or P1153: Air/Fuel Sensor Circuit Response Malfunction
- DTC P1135 Or P1155: Air/Fuel Sensor Heater Circuit Malfunction
- DTC P1300, P1305, P1310, P1315, P1320 Or P1325: IGNITOR Circuit Malfunction
- DTC P1335: Crankshaft Position Sensor Circuit Malfunction (During Engine Running)
- DTC P1346 Or P1351: Variable Valve Timing (VVT) Sensor/Crankshaft Position Sensor Circuit Range/Performance Fault (Bank No. 1 & 2)
- DTC P1349 Or P1354: Variable Valve Timing (VVT) System Malfunction
- DTC P1350: Variable Valve Timing (VVT) Circuit Malfunction
- DTC P1520: Stoplight Switch Signal Malfunction
- DTC P1600: ECM Batt Malfunction
- DTC P1656 Or P1663: Oil Control Valve (OCV) Malfunction
- DTC P1780: Park/Neutral Position Switch Malfunction
Factory Service Tools
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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.
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