Inspection Procedure

NOTE: Hand-held tester only:

Narrowing down the trouble area is possible by performing the "SENSOR 1 (FRONT SENSOR)" ACTIVE TEST (heated oxygen sensor or other trouble areas can be distinguished).

Perform ACTIVE TEST using the hand-held tester (A/F CONTROL).
NOTE:
"A/F CONTROL" is ACTIVE TEST which changes the injection volume -12.5 % or +25 %.
1. Connect the hand-held tester to the DLC3 on the vehicle.
2. Turn the ignition switch ON.
3. Warm up the engine by running the engine at 2,500 rpm for approximately 3 minutes.
4. Select the item "DIAGNOSIS/ENHANCED OBD II/ACTIVE TEST/ A/F CONTROL".
5. 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: There is a delay of few seconds in the sensor 1 (front sensor) output, and there is about 20 seconds delay at maximum in the sensor 2 (rear sensor).

Fig 1: Heated Oxygen Sensor Injection Volume Position
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The following A/F CONTROL procedure enables the technician to check and graph the voltage outputs of both the heated oxygen sensors.

For displaying the graph indication, enter "ACTIVE TEST / A/F CONTROL / USER DATA", then select "O2S B1S1 and O2S B1S2" by pressing "YES" button and push "ENTER" button before pressing "F4" button.
NOTE:
- If different DTCs related to different systems that have 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.

CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0136)

Connect the hand-held tester or the OBD II scan tool to the DLC3.
Turn the ignition switch ON and push the hand-held tester or the OBD II scan tool main switch ON.
Select the item "DIAGNOSIS / OBD/MOBD / DTC INFO / CURRENT CODES".

Read the DTCs using the hand-held tester or the OBD II scan tool.

Result:

DTCS OUTPUT

Display (DTC Output)	Proceed To
Only "P0136" Is Output	A
"P0136" And Other DTCs Are Output	B

NOTE: If any other codes besides "P0136" is output, perform the troubleshooting for those DTCs first.

B : GO TO RELEVANT DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )
A : Go to next step.

READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR)
1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
2. Start the engine and push the hand-held tester or the OBD II scan tool main switch ON.
3. Select the item "DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / O2S B1S1".
4. After warming up the engine, run the engine at 2,500 rpm for 3 minutes.
5. Read the output voltage of the heated oxygen sensor when the engine speed is suddenly increased.
  NOTE: Quickly accelerate the engine to 4,000 rpm 3 times by using the accelerator pedal.
  
  Standard:
  
  Heated oxygen sensor output voltage: Alternates from 0.4 V or less to 0.5 V or more.
1. OK : Go to step 6 .
2. NG : Go to next step.

INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)

Disconnect the H6 heated oxygen sensor connector.

Fig 2: Identifying H6 Heated Oxygen Sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance between the terminals of the heated oxygen sensor connector.

Standard:

STANDARD

Tester Connection	Specified Condition
HT (H6-1) - +B (H6-2)	11 to 16 Ω at 20 °C (68 °F)
HT (H6-1) - E1 (H6-4)	10 kΩ Or Higher

Reconnect the heated oxygen sensor connector.

NG : REPLACE HEATED OXYGEN SENSOR
OK : Go to next step.

INSPECT EFI RELAY

Remove the EFI relay from the engine room R/B.

Inspect the EFI relay.

Standard:

STANDARD SPECIFICATION

Tester Connection	Specified Condition
1 - 2	Continuity
3 - 5	No Continuity
3 - 5	Continuity (Apply Battery Voltage To Terminals 1 & 2)

Reinstall the EFI relay.

Fig 3: EFI Relay Connecting Diagram
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : REPLACE EFI RELAY
OK : Go to next step.

CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)

Disconnect the H6 heated oxygen sensor connector.

Fig 4: Identifying H6 Heated Oxygen Sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the E4 and E5 ECM connectors.

Fig 5: Identifying E4 & E5 ECM Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance between the wire harness side connectors.

Standard (Check for open):

STANDARD (CHECK FOR OPEN)

Tester Connection	Specified Condition
HT (H6-1) - HTL2 (E5-4)	Below 1 Ω
OX (H6-3) - OXL2 (E4-21)	Below 1 Ω

Standard (Check for short):

STANDARD (CHECK FOR SHORT)

Tester Connection	Specified Condition
HT (H6-1) or HTL2 (E5-4) - Body Ground	10 kΩ or higher
OX (H6-3) or OXL2 (E4-21) - Body Ground	10 kΩ or higher

Reconnect the heated oxygen sensor connector.

Fig 6: Heated Oxygen Sensor To ECM Connecting Diagram

Reconnect the ECM connector.

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR
OK : REPLACE HEATED OXYGEN SENSOR

PERFORM CONFIRMATION DRIVING PATTERN (See DTC CHECK/CLEAR 6)
NOTE: Clear all DTCs prior to performing the confirmation driving pattern.
1. GO: Go to next step.

READ OUTPUT DTC (DTC P0136 IS OUTPUT AGAIN)

Connect the hand-held tester or the OBD II scan tool to the DLC3.
Turn the ignition switch ON and push the hand-held tester or the OBD II scan tool main switch ON.
Select the item "DIAGNOSIS / OBD/MOBD / DTC INFO / CURRENT CODES".

Read the DTCs using the hand-held tester or the OBD II scan tool.

Result:

RESULT

Display (DTC Output)	Proceed To
"P0136" Is Output Again	A
"P0136" Is Not Output Again	B

B : CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )
A : REPLACE HEATED OXYGEN SENSOR