Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus GS 430. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

It is possible the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL operation.

The ACTIVE TEST can determine if the heated oxygen sensor or other potential trouble areas are malfunctioning or not.

The injection volume can be switched to -12.5% (decrease) or +25% (increase) by the ACTIVE TEST.

The ACTIVE TEST procedure enables a technician to check and graph the output voltage of the heated oxygen sensors.

Procedure:

Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
Turn the engine switch on (IG).
Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
Perform the ACTIVE TEST while the engine is idling.

Standard:

The heated oxygen sensor reacts in accordance with the increase and decrease of injection volume:

+25% → RICH output: More than 0.55 V

-12.5% → LEAN output: Less than 0.4 V

NOTE: The heated oxygen sensor (sensor 1) output has a few seconds of delay and the heated oxygen sensor (sensor 2) output has a maximum of 20 seconds of delay.
If the vehicle is short on fuel, the air-fuel ratio becomes LEAN and the DTCs will be recorded.

Fig 1: Heated Oxygen Sensor Voltage Reference Chart

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was LEAN or RICH, and other data from the time the malfunction occurred.
Bank 1 refers to the bank that includes No. 1 cylinder.
Bank 2 refers to the bank that does not include No. 1 cylinder.
No. 1 cylinder is located in the front part of the engine, opposite the transmission.
Sensor 1 refers to the sensor closest to the engine body.

CHECK OTHER DTC OUTPUT

Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
Read the DTCs.

Result

RESULT CHART

Display (DTC output)	Proceed to
P0134 or P0154	A
P0134 or P0154 and other DTCs	B

B: GO TO RELEVANT DTC CHART

A: Go to next step

READ DATA LIST (HEATED OXYGEN SENSOR (SENSOR 1) VOLTAGE)
1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / O2S B1S1 (O2S B2S1).
3. Allow the engine to idle until the ECT reaches 40°C (104°F).
4. Quickly depress the accelerator pedal 3 times until the engine RPM reaches 4,000 rpm. Then, read the heated oxygen sensor (sensor 1) voltage.
  Standard voltage:
  
  The heated oxygen sensor (sensor 1) voltage is 0.45 V or more at least once.
OK: Go to step 11

NG: Go to next step
CHECK CONNECTION PCV HOSE
OK:

PCV hose is connected correctly and is not damaged.

NG: REPAIR OR REPLACE PCV HOSE

OK: Go to next step

INSPECT HEATED OXYGEN SENSOR

Disconnect the E23 and E44 sensor connectors.

Measure the resistance of the sensor.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
1 (HT1A) - 2 (+B)	11 to 16 Ω
1 (HT2A) - 2 (+B)	11 to 16 Ω
1 (HT1A) - 4 (E2)	10 kΩ or higher
1 (HT2A) - 4 (E2)	10 kΩ or higher

Fig 2: Identifying E23 And E44 Sensor Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE HEATED OXYGEN SENSOR

OK: Go to next step

INSPECT INTEGRATION RELAY (EFI MAIN)

Remove the integration relay from the engine room No. 2 junction block.

Measure the resistance of the EFI MAIN relay.

Standard resistance

TERMINAL CONNECTIONS SPECIFIED CONDITION CHART

Terminal Connections	Specified Condition
2A-8 - 2C-1	10 kΩ or higher
2A-8 - 2C-1	Below 1 Ω (when battery voltage is applied to terminals 2A-6 and 2A-7)

Fig 3: Identifying Integration Relay Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE INTEGRATION RELAY

OK: Go to next step

CHECK WIRE HARNESS (HEATED OXYGEN SENSOR (SENSOR 1) - ECM)

Disconnect the E23 and E44 sensor connectors.
Disconnect the E6 and E8 ECM connectors.

Measure the resistance of the wire harness side connectors.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION

Tester Connection	Specified Condition
E23-1 (HT1A) - E8-24 (HT1A)	Below 1 Ω
E23-3 (OX1A) - E8-30 (OX1A)	Below 1 Ω
E44-1 (HT2A) - E6-5 (HT2A)	Below 1 Ω
E44-3 (OX2A) - E6-28 (OX2A)	Below 1 Ω
E23-1 (HT1A) or E8-24 (HT1A) - Body ground	10 kΩ or higher
E23-3 (OX1A) or E8-30 (OX1A) - Body ground	10 kΩ or higher
E44-1 (HT2A) or E6-5 (HT2A) - Body ground	10 kΩ or higher
E44-3 (OX2A) or E6-28 (OX2A) - Body ground	10 kΩ or higher

Fig 4: Identifying E6 And E8 ECM Connectors

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step

CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leaks.
  OK:
  
  There are no vacuum leaks in air induction system.
NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK: Go to next step
CHECK FUEL PRESSURE
1. Check the fuel pressure (see REMOVAL ).
NG: REPAIR OR REPLACE FUEL SYSTEM

OK: Go to next step
INSPECT FUEL INJECTOR
1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).
NG: REPLACE FUEL INJECTOR

OK: Go to next step
CHECK FOR EXHAUST GAS LEAKAGE
NG: REPAIR OR REPLACE EXHAUST SYSTEM

OK: REPLACE HEATED OXYGEN SENSOR
PERFORM CONFIRMATION DRIVING PATTERN
HINT:

Clear all DTCs before performing the confirmation driving pattern.

READ OUTPUT DTC (DTC P0134 OR P0154 IS OUTPUT AGAIN)

Clear the DTC (see DTC CHECK / CLEAR ).
Start the engine and allow the engine to idle for 15 seconds or more.
Read the DTC.

Result

RESULT CHART

Display (DTC output)	Proceed to
None	A
P0134 or P0154	B

B: REPLACE ECM

A: Go to next step

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL
1. If the vehicle has run out of fuel, proceed to A.
2. If the vehicle has not run out of fuel, proceed to B.
B: CHECK FOR INTERMITTENT PROBLEMS

A: DTC IS CAUSED BY RUNNING OUT OF FUEL