Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

hand-held tester only:

The narrowing down the trouble area is possible by performing ACTIVE TEST of the following "A/F CONTROL" (Heated oxygen sensor or another can be distinguished).

Perform ACTIVE TEST by hand-held tester (A/F CONTROL).

HINT:

"A/F CONTROL" is the ACTIVE TEST which changes the injection volume to- 12.5% or +25%.

Connect the hand-held tester to the DLC3 on the vehicle.
Turn the ignition switch ON.
Warm up the engine with the engine with the engine speed at 2,500 RPM for approximately 90 seconds.
Select the item "DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL".
Perform "A/F CONTROL" with the engine in an idle condition (press the right or left button).

RESULT:

Heated oxygen sensor reacts in accordance with increase and decrease of injection volume

+25% -> rich output: More than 0.5 V

-12.5% -> lean output: Less than 0.4 V

NOTE: However, there is a few seconds delay in the sensor 1 (front sensor) output. And there is about 20 seconds delay in the sensor 2 (rear sensor).

Fig 1: Heater Oxygen Sensors Voltage Output Chart

The following A/F CONTROL procedure enables the technician to check and graph the voltage output of the heated oxygen sensors (sensor 1 and 2).

For displaying the graph indication, enter "ACTIVE TEST / A/F CONTROL / USER DATA" then select "07 B1S1 and O2S B1S2" by pressing "YES" button and push "ENTER" button before pressing "F4" button.

HINT:

If different DTCs related to different systems terminal E2 as the ground terminal are output simultaneously, terminal E2 may be open.
Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
A high heated oxygen sensor (sensor 1) voltage (0.5 V or more) could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.
A low heated oxygen sensor (sensor 1) voltage (0.4 V or less) could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.

Are there any other codes (besides DTC P0134 and P0154) being output?
PREPARATION:
1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
2. Turn the ignition switch ON and push the hand-held tester or the OBD II scan tool main switch ON.
3. When using hand-held tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
CHECK:

Read the DTC using the hand-held tester of the OBD II scan tool.

RESULT:

Fig 2: Display (DTC Output) Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

If any other codes besides P0134 and/or P0154 are output, perform the troubleshooting for those codes first.
1. A: Go to relevant DTC chart (See DIAGNOSTIC TROUBLE CODE CHART ).
2. B: Go to next step.
Connect the OBD II scan tool or hand-held tester, and read value for voltage out-put of heated oxygen sensors (bank 1, 2 sensor 1).
PREPARATION:
1. Connect the OBD II scan tool or hand-held tester to the DLC3.
2. Warm up the engine to normal operating temperature (above 75°C (169°F).
3. When using hand-held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / O2S B1 S1 or B2 S1.
CHECK:

Read the voltage output of the heated oxygen sensors when the engine is suddenly raced.

HINT:

Perform quick racing to 4,000 RPM 3 times using the accelerator pedal.

OK:

Heated oxygen sensor output a RICH signal (0.45 V or more) at least once.
1. OK: Go to step 12 .
2. NG: Go to next step.
Check connection of PCV piping.
1. NG: Repair or replace PCV piping.
2. OK: Go to next step.
Check resistance of heated oxygen sensor heater (See INSPECTION ).
1. NG: Replace heated oxygen sensor.
2. OK: Go to next step.
Check EFI relay (See EFI MAIN RELAY ).
1. NG: Replace EFI relay.
2. OK: Go to next step.
Check for open and short in harness and connector between ECM and heated oxygen sensors (bank 1,2 sensor 1) (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).

Fig 3: Bank 1 Sensor 1 System Drawing Circuit Diagram
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Repair or replace harness or connector.
2. OK: Go to next step.
Check whether misfire is occurred or not by monitoring DTC and data list.
1. NG: Perform troubleshooting for misfire (See DTC P0300 Random/Multiple Cylinder Misfire Detected, DTC P0301 Cylinder 1 Misfire Detected, DTC P0302 Cylinder 2 Misfire Detected, DTC P0303 Cylinder 3 Misfire Detected, DTC P0304 Cylinder 4 Misfire Detected, DTC P0305 Cylinder 5 Misfire Detected, DTC P0306 Cylinder 6 Misfire Detected ).
2. OK: Go to next step.
Check air induction system (See SFI SYSTEM ).
CHECK:

Check the air induction system for vacuum leaks.
1. NG: Repair or replace air induction system.
2. OK: Go to next step.
Check fuel pressure (See FUEL PUMP ).
CHECK:

Check the fuel pressure (high or low pressure).
1. NG: Check and repair fuel pump, pressure regulator, fuel pipe line and filter (See SFI SYSTEM ).
2. OK: Go to next step.
Check injector injection (See INSPECTION )
1. NG: Replace injector
2. OK: Go to next step.
Check gas leakage on exhaust system.
1. NG: Repair or replace exhaust gas leakage point.
2. OK: Replace heated oxygen sensor (bank 1,2 sensor 1).
Perform confirmation driving pattern (See DTC P0130: Oxygen Sensor Circuit (Bank 1 Sensor 1), DTC P0150: Oxygen Sensor Circuit (Bank 2 Sensor 1), DTC P2195: Oxygen Sensor Signal Stack Lean (Bank 1 Sensor 1), DTC P2196: Oxygen Sensor Signal Stack Rich (Bank 1 Sensor 1), DTC P2197: Oxygen Sensor Signal Stack Lean (Bank 2 Sensor 1), DTC P2198: Oxygen Sensor Signal Stack Rich (Bank 2 Sensor 1) .
HINT:

Clear all DTCs prior to performing the confirmation driving pattern.
1. GO: Go to next step.
Is there DTC P0134 and P0154 being output again?
1. YES: Replace ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
2. NO: Go to next step.
Did vehicle runs out of fuel in past?
1. NO: Check for Intermittent problems (See PRE-CHECK ).
2. YES: DTCs P0134 and P0154 are caused by running out of fuel.