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Home >> Lexus >> 2004 >> IS 300 Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 52 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0134: Oxygen (A/F) Sensor Circuit No Activity Detected (Bank 1, Sensor 1) & DTC P0154: Oxygen (A/F) Sensor Circuit No Activity Detected (Bank 2, Sensor 1) >> Diagnosis & Repair
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Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. If any other DTCs are set, diagnose them first. If no other DTCs are set, check PCV hose connection and repair as necessary. If PCV hose is okay, go to next step.
  2. Connect the OBD-II scan tool or hand-held tester to the DLC3. Warm up the A/F sensors (bank 1, 2 sensor 1) with the engine at 2500 RPM for approximately 90 seconds. On hand-held tester, select the ENHANCED OBD2/SNAPSHOT/MANUAL SNAP SHOT/ ALL mode. With either tester, read the voltage of A/F sensors (bank 1, 2 sensor 1) on the screen of the OBD-II scan tool or hand-held tester when performing conditions outlined in next step.
    NOTE: The voltage of AFR(+) - E1 (-) or AFL(+) - E1 (-) terminals of ECM is fixed at 3.3 volts and the voltage of terminals AFR (-) - E1 or AFL (-) - E1 (-) is fixed at 3.0 volts.
  3. Under normal conditions, with engine idling or racing at approximately 2500 RPM, (when engine revolution is not suddenly changed) voltage value changes a little in the vicinity of 3.3 volts (0.660 volts on OBD-II scan tool) between approximately 3.1-3.5 volts. With engine RPM increased to approximately 4000 RPM temporarily, then decreased to idle speed with accelerator completely released, voltage value changes into 3.8 volts (0.76 volts with OBD-II scan tool) or more temporarily. See Fig 1. Under a malfunction condition, voltage value does not change at all. See Fig 2. If system does not operate correctly, go to next step. If system operates correctly, go to step  7.
    Fig 1: Vehicle Normal Condition
    G00165052Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Vehicle Abnormal Condition
    G00165053Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    NOTE: Whenever the output voltage of the A/F sensors remains at approximately 3.3 volts (0.660 volts with OBD-II scan tool under any conditions as well as the above conditions, the A/F sensors may have an open circuit. This will happen also when the A/F sensor heater has an open circuit. Whenever the output voltage of the A/F sensors remains at a certain value of approximately 3.8 volts (0.76 volts on OBD-II scan tool) or more, or 2.8 volts (0.56 volts on OBD-II scan tool) or less under any conditions as well as the above conditions, the A/F sensor may have a short circuit.
  4. Check for open and short in harness and connector between ECM and A/F sensors (bank 1 and/or 2 sensor 1). Repair or replace harness or connector as necessary. If harness and connector are okay, go to next step.
  5. Check resistance of A/F sensor heater. See SENSOR OPERATING RANGE CHARTS article. Replace A/F sensor as necessary. If sensor is okay, check air induction system. See AIR INDUCTION SYSTEMS in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. Repair or replace as necessary. If air induction system is okay, check fuel pressure. See FUEL SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. Check and repair fuel pump, fuel pipe line and filter. Repair as necessary. If pump, line and filter are okay, check injector injection. See FUEL SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. Replace injector as necessary. If injector is okay, go to next step.
  6. Check gas leakage on exhaust system. Repair or replace as necessary. If no gas leakage is present, replace A/F sensor (bank 1 and/or 2 sensor 1), then perform confirmation driving pattern. See CONFIRMATION DRIVING PATTERN  under DTC P0134 & P0154. If DTC P0134 and/or P0154 are output again, check and replace ECM. If DTC P0134 and/or P0154 are not output again, check if vehicle ran out of fuel in the past. If not, check for intermittent problems. If yes, DTC P0134 and/or P0154 is caused by shortage of fuel.
  7. Perform confirmation driving pattern. See CONFIRMATION DRIVING PATTERN  under DTC P0134 & P0154. If DTC P0134 and/or P0154 are not output again, go to next step. If DTCs are output again, replace A/F sensors (bank 1 and/or 2 sensor). Perform confirmation driving pattern. See CONFIRMATION DRIVING PATTERN  under DTC P0134 & P0154. If P0134 and/or P0154 are output again, check and replace ECM.
  8. Check if vehicle ran out of fuel in the past. If not, check for intermittent problems. If yes, DTC P0134 and/or P0154 is caused by shortage of fuel.
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