Brand:

Toyota

Model Name:

Yaris NCP90 91 92 93

Manual:

Repair Manual

Section:

1Nz-Fe Engine Control System

Title:

Sfi System

  1. Description

  2. Wiring diagram

  3. Confirmation driving pattern

  4. Inspection procedure

  5. Check any other dtcs output (in addition to dtc p0136)

  6. Read value using intelligent tester (output voltage of heated oxygen sensor (sensor 2))

  7. Inspect heated oxygen sensor (heater resistance)

  8. Inspect integration no.1 relay (efi relay)

  9. Check harness and connector (heated oxygen sensor (sensor 2) - ecm)

  10. Perform confirmation driving pattern

  11. Check whether dtc output recurs (dtc p0136)

DTC P0136 Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 2)

HINT:
Sensor 2 refers to the sensor mounted behind the Three-Way Catalytic Converter (TWC) and located far from the engine assembly.

DESCRIPTION

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel level. For the purpose of helping the ECM to deliver accurate air-fuel ratio control, a Heated Oxygen (HO2) sensor is used. The HO2 sensor is located behind the TWC, and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).
When the air-fuel ratio becomes lean, the oxygen concentration in the exhaust gas is rich. The HO2 sensor indicates to the ECM that the post-TWC air-fuel ratio is lean (low voltage, i.e. less than 0.45 V).
Conversely, when the air-fuel ratio is richer than the stoichiometric air-fuel level, the oxygen concentration in the exhaust gas becomes lean. The HO2 sensor indicates to the ECM that the post-TWC air-fuel ratio is rich (high voltage, i.e. more than 0.45 V). The HO2 sensor has the property of changing its output voltage drastically when the air-fuel ratio is close to the stoichiometric level. The ECM uses the supplementary information from the HO2 sensor to determine whether the air-fuel ratio after the TWC is rich or lean, and adjusts the fuel injection time accordingly. Thus, if the HO2 sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air-fuel ratio control.

(a) Vehicle driven in 10 STOP-and-GO* cycles Yaris


DTC No.
DTC Detection Conditions
Trouble Areas
P0136
Following conditions (a) and (b) met for 4 minutes or more after engine warmed up (2 trip detection logic):
  1. (a) Vehicle driven in 10 STOP-and-GO* cycles
  2. (b) Heated Oxygen (HO2) sensor (sensor 2) voltage remains at 0.4 V or more or 0.5 V or less.
  1. Open or short in HO2 sensor (sensor 2) circuit
  2. HO2 sensor (sensor 2)
  3. HO2 sensor (sensor 2) heater
  4. Integration relay (EFI relay)
All of following conditions (a), (b), (c), (d) and (e) set (2 trip detection logic):
  1. (a) Cumulative sensor monitoring time 110 seconds or more
  2. (b) Cumulative time while rear HO2 sensor voltage less than 0.05 V 99 seconds or more
  3. (c) Cumulative time while rear HO2 sensor voltage 0.7 V or more less than 22 seconds
  4. (d) Cumulative time while rear HO2 sensor voltage 0.45 V or more less than 44 seconds
  5. (e) Maximum continuous time while rear HO2 sensor voltage 0.45 V or more less than 20 seconds
HINT:
*: STOP refers to a vehicle speed of less than 5 km/h (3.1 mph) and GO refers to a vehicle speed of more than 28 km/h (17.4 mph)

WIRING DIAGRAM


(a) Connect an intelligent tester to the DLC3. Yaris


CONFIRMATION DRIVING PATTERN


(a) Connect an intelligent tester to the DLC3. Yaris

HINT:
This confirmation driving pattern is used in the "PERFORM CONFIRMATION DRIVING PATTERN" procedure of the following diagnostic troubleshooting procedure.
  1. (a) Connect an intelligent tester to the DLC3.
  2. (b) Turn the ignition switch to ON and turn the tester on.
  3. (c) Clear DTCs (Click here).
  4. (d) Switch the ECM from normal mode to check mode (Click here).
  5. (e) Start the engine.
  6. (f) Allow the engine to idle for 60 seconds.
  7. (g) Drive the vehicle at a vehicle speed of more than 30 km/h (19 mph) for 40 seconds or more.
  8. (h) Allow the engine to idle for 10 seconds or more.
  9. (i) Repeat steps (g) and (h) described above at least 9 times.
NOTICE:
If the conditions in this test are not strictly followed, malfunctions may not be detected.

INSPECTION PROCEDURE

HINT:
It is possible that the malfunctioning area can be found using the Active Test 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 voltage outputs of the heated oxygen sensors.
  1. Procedure:
    1. Connect an intelligent tester to the DLC3.
    2. Turn the ignition switch to ON.
    3. Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
    4. Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
    5. Perform the Active Test while the engine is idling.
Standard:
The heated oxygen sensor reacts in accordance with the increases and decreases in injection volume:
+25% → RICH output: More than 0.5 V
-12.5% → LEAN output: Less than 0.4 V
NOTICE:
The heated oxygen sensor (sensor 1) has an output delay of a few seconds and the heated oxygen sensor (sensor 2) has a maximum output delay of 20 seconds.
If the vehicle is short of fuel, the air-fuel ratio becomes LEAN and the DTCs are recorded.

Case
Heated Oxygen Sensor (Sensor 1) Output Voltage
Heated Oxygen Sensor (Sensor 2) Output Voltage
Main Suspected Trouble Area
1
Heated oxygen sensor (Sensor 1) Yaris
Heated oxygen sensor (Sensor 1) Yaris
Heated oxygen sensor (Sensor 1) Yaris
Heated oxygen sensor (Sensor 1) Yaris
-
2
Heated oxygen sensor (Sensor 1) Yaris
Heated oxygen sensor (Sensor 1) Yaris
Heated oxygen sensor (Sensor 1) Yaris
Heated oxygen sensor (Sensor 1) Yaris
  1. Heated oxygen sensor (Sensor 1)
  2. Heated oxygen sensor heater (Sensor 1)
  3. Heated oxygen sensor circuit (Sensor 1)
3
Heated oxygen sensor (Sensor 2) Yaris
Heated oxygen sensor (Sensor 2) Yaris
Heated oxygen sensor (Sensor 2) Yaris
Heated oxygen sensor (Sensor 2) Yaris
  1. Heated oxygen sensor (Sensor 2)
  2. Heated oxygen sensor heater (Sensor 2)
  3. Heated oxygen sensor circuit (Sensor 2)
4
Injector Yaris
Injector Yaris
Injector Yaris
Injector Yaris
  1. Injector
  2. Fuel pressure
  3. Gas leak from exhaust system (Air-fuel ratio extremely RICH or LEAN)
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.
1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0136)

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Select the following menu items: Powertrain / Engine and ECT / DTC.

  1. Read DTCs.

    Result:
    Display (DTC Output)
    		Proceed To
    P0136
    		A
    P0136 and other DTCs
    		B
    HINT:
    If any DTCs other than P0136 are output, troubleshoot those DTCs first.


Bnext
GO TO DTC CHART (Click here)
A
next down

2.READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR (SENSOR 2))

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Select the following menu items: Powertrain / Engine and ECT / Data List / O2S B1 S2.

  1. Allow the engine to run at 2,500 rpm for 3 minutes.

  1. Depress the accelerator pedal quickly until the engine rpm reaches 4,000 rpm 3 times.

    Standard voltage:
    Heated Oxygen (HO2) sensor voltage alternates between below 0.4 V and 0.5 V or more.

Disconnect the D28 HO2 sensor (sensor 2) connector. Yaris



OKnext
Go to step 6
NG
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3.INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)
Disconnect the D28 HO2 sensor (sensor 2) connector. Yaris

  1. Disconnect the D28 HO2 sensor (sensor 2) connector.

  1. Measure the resistance.

    Standard resistance:
    Tester Connections
    		Specified Conditions
    HT1B (1) - +B (2)
    		11 to 16 Ω at 20°C (68°F)
    HT1B (1) - E2 (4)
    		10 kΩ or higher

  1. Reconnect the HO2 sensor connector.



NGnext
REPLACE HEATED OXYGEN SENSOR (Click here)
OK
next down

4.INSPECT INTEGRATION NO.1 RELAY (EFI RELAY)
Remove the integration relay from the engine room relay block. Yaris

  1. Remove the integration relay from the engine room relay block.

  1. Inspect the EFI fuse.

    1. Remove the EFI fuse from the integration relay.

    2. Check the EFI fuse resistance.

      Standard resistance:
      Below 1 Ω

    3. Reinstall the EFI fuse.

  1. Inspect the EFI relay.

    1. Check the EFI relay resistance.

      Standard resistance:
      Tester Connections
      		Specified Conditions
      1C-1 - 1A-4
      		10 kΩ or higher
      Below 1 Ω
      (Apply battery voltage between terminals 1A-2 and 1A-3)

  1. Reinstall the integration relay.



NGnext
REPLACE INTEGRATION NO.1 RELAY
OK
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5.CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR (SENSOR 2) - ECM)
Disconnect the D28 HO2 sensor (sensor 2) connector. Yaris

Disconnect the D28 HO2 sensor (sensor 2) connector. Yaris

  1. Disconnect the D28 HO2 sensor (sensor 2) connector.

  1. Disconnect the C20 ECM connector.

  1. Check the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    OX1B (D28-3) - OX1B (C20-64)
    		Below 1 Ω
    HT1B (D28-1) - HT1B (C20-47)
    Standard resistance (Check for short):
    Tester Connections
    		Specified Conditions
    OX1B (D28-3) or OX1B (C20-64) - Body ground
    		10 kΩ or higher
    HT1B (D28-1) or HT1B (C20-47) - Body ground

  1. Reconnect the ECM connector.

  1. Reconnect the HO2 sensor connector.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
next down
REPLACE HEATED OXYGEN SENSOR (Click here)

6.PERFORM CONFIRMATION DRIVING PATTERN
HINT:
Clear all DTCs before performing the confirmation driving pattern.

NEXT
next down

7.CHECK WHETHER DTC OUTPUT RECURS (DTC P0136)

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch to ON and turn the tester on.

  1. Select the following menu items: Powertrain / Engine and ECT / DTC.

  1. Read DTCs.

    Result:
    Display (DTC Output)
    		Proceed To
    P0136
    		A
    No output
    		B


Bnext
CHECK FOR INTERMITTENT PROBLEMS (Click here)
A
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REPLACE HEATED OXYGEN SENSOR (Click here)