Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VIAI
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 - 08/2016]
Title: 2GR-FE (ENGINE CONTROL): SFI SYSTEM: P0031,P0032,P0051,P0052,P101D,P103D; Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1); 2016 MY Sienna [12/2015 - 08/2016]

DTC

P0031

Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)

DTC

P0032

Oxygen (A/F) Sensor Heater Control Circuit High (Bank 1 Sensor 1)

DTC

P0051

Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 2 Sensor 1)

DTC

P0052

Oxygen (A/F) Sensor Heater Control Circuit High (Bank 2 Sensor 1)

DTC

P101D

A/F Sensor Heater Circuit Performance Bank 1 Sensor 1 Stuck ON

DTC

P103D

A/F Sensor Heater Circuit Performance Bank 2 Sensor 1 Stuck ON

DESCRIPTION

HINT:

  • Although the DTC titles include oxygen sensor, these DTCs relate to the air fuel ratio sensor.
  • Sensor 1 refers to the sensor mounted in front of the three way catalytic converter and located near the engine assembly.

The air fuel ratio sensor generates voltage* that corresponds to the actual air fuel ratio. This sensor voltage is used to provide the ECM with feedback so that it can control the air fuel ratio. The ECM determines the deviation from the stoichiometric air fuel ratio level, and regulates the fuel injection time. If the air fuel ratio sensor malfunctions, the ECM is unable to control the air fuel ratio accurately.

The air fuel ratio sensor is the planar type and is integrated with a heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), a current flows into the heater to heat the sensor, in order to facilitate accurate oxygen concentration detection. In addition, the sensor and heater portions are narrower than the conventional type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, and therefore the sensor activation is accelerated.

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 three way catalytic converter is used. For the most efficient use of the three way catalytic converter, the air fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

*: Value changes inside the ECM. Since the air fuel ratio sensor is the current output element, the current is converted to a voltage inside the ECM. Any measurements taken at the air fuel ratio sensor or ECM connectors will show a constant voltage.

HINT:

  • When any of these DTCs are stored, the ECM enters fail-safe mode. The ECM turns off the air fuel ratio sensor heater in fail-safe mode. Fail-safe mode continues until the ignition switch is turned off.
  • The ECM provides a pulse width modulated control circuit to adjust the current through the heater. The air fuel ratio sensor heater circuit uses a relay on the +B side of the circuit.

DTC No.

DTC Detection Condition

Trouble Area

P0031

P0051

Air fuel ratio sensor heater (bank 1, 2 sensor 1) current less than 0.8 A

(1 trip detection logic)
  • Open in air fuel ratio sensor heater (bank 1, 2 sensor 1) circuit
  • Air fuel ratio sensor heater (bank 1, 2 sensor 1)
  • A/F fuse
  • A/F HTR relay
  • ECM

P0032

P0052

Air fuel ratio sensor heater (bank 1, 2 sensor 1) current fail

(1 trip detection logic)
  • Short in air fuel ratio sensor heater (bank 1, 2 sensor 1) circuit
  • Air fuel ratio sensor heater (bank 1, 2 sensor 1)
  • A/F fuse
  • A/F HTR relay
  • ECM

P101D

P103D

The heater current is higher than the specified value while the heater is not operating

(1 trip detection logic)

ECM

MONITOR DESCRIPTION

  • The ECM uses information from the air fuel ratio sensor to regulate the air fuel ratio and keep it close to the stoichiometric level. This maximizes the ability of the three way catalytic converter to purify the exhaust gases.
  • The air fuel ratio sensor detects oxygen levels in the exhaust gas and transmits the information to the ECM. The inner surface of the sensor element is exposed to the outside air. The outer surface of the sensor element is exposed to the exhaust gas. The sensor element is made of platinum coated zirconia and includes an integrated heating element.
  • The zirconia element generates a small voltage when there is a large difference in the oxygen concentrations between the exhaust gas and outside air. The platinum coating amplifies this voltage generation.
  • The air fuel ratio sensor is more efficient when heated. When the exhaust gas temperature is low, the sensor cannot generate useful voltage signals without supplementary heating. The ECM regulates the supplementary heating using a duty-cycle approach to adjust the average current in the sensor heater element. If the heater current is outside the normal range, the signal transmitted by the air fuel ratio sensor will be inaccurate, as a result, the ECM will be unable to regulate air fuel ratio properly.
  • When the current in the air fuel ratio sensor heater is outside the normal operating range, the ECM interprets this as a malfunction in the sensor heater and stores a DTC.

MONITOR STRATEGY

Related DTCs

P0031: Air fuel ratio sensor heater (bank 1 sensor 1) heater range check (Low current)

P0032: Air fuel ratio sensor heater (bank 1 sensor 1) heater range check (High current)

P0051: Air fuel ratio sensor heater (bank 2 sensor 1) heater range check (Low current)

P0052: Air fuel ratio sensor heater (bank 2 sensor 1) heater range check (High current)

P101D: Air fuel ratio sensor (bank 1 sensor 1) heater performance

P103D: Air fuel ratio sensor (bank 2 sensor 1) heater performance

Required sensors/Components (Main)

Air fuel ratio sensor heater

Required sensors/Components (Related)

-

Frequency of operation

Continuous

Duration

1 second: P101D and P103D

10 seconds: P0031 and P0051

10.24 seconds: P0032 and P0052

MIL operation

Immediately

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

Monitor runs whenever following DTCs are not present

None

P0031 and P0051

All of the following conditions are met

-

Battery voltage

10.5 V or higher

Active heater off control

Not operating

Active heater on control

Not operating

Air fuel ratio sensor heater performance fail (P101D, P103D)

Not detected

Heater output duty cycle

30% or higher

P0032 and P0052

All of the following conditions are met

-

Battery voltage

10.5 V or higher

Time after heater on

5 seconds or more

Heater output duty cycle

Higher than 0%

Active heater off control

Not operating

Active heater on control

Not operating

P101D and P103D

All of the following conditions are met

-

Battery voltage

10.5 V or higher

Time after heater on

5 seconds or more

Air fuel ratio sensor heater low current fail (P0031, P0051)

Not detected

Heater output duty cycle

Less than 60%

Heater current detected by heater monitor IC

14 A or more

Active heater off control

Not operating

Active heater on control

Not operating

TYPICAL MALFUNCTION THRESHOLDS

P0031 and P0051

Heater on current

Less than 0.8 A

P0032 and P0052

All of the following conditions are met:

-

Command to heater output

ON

Heater current detected by heater monitor IC

14 A or more

P101D and P103D

All of the following conditions are met

-

Heater current detected by heater monitor IC

14 A or more

Heater off current

More than 11 A

COMPONENT OPERATING RANGE

P0031 and P0051

Heater on current

0.8 A or more

P0032 and P0052

All of the following conditions are met

-

Command to heater output

ON

Heater current detected by heater monitor IC

Less than 14 A

P101D and P103D

Heater off current

11 A or less

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR ).
  4. Turn the ignition switch off and wait for at least 30 seconds.
  5. Turn the ignition switch to ON and turn the Techstream on [A].
  6. Start the engine and idle it for 5 minutes or more [B].
  7. With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of 3000 rpm for 1 minute [C].
  8. Idle the engine for 5 minutes or more [D].
  9. Enter the following menus: Powertrain / Engine / Trouble Codes [E].
  10. Read pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  11. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
  12. Input the DTC: P0031, P0032, P0051, P0052, P101D or P103D.
  13. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL
    • DTC judgment completed
    • System normal

    ABNORMAL
    • DTC judgment completed
    • System abnormal

    INCOMPLETE
    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    N/A
    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
  14. If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [E] again.
  15. If no pending DTC is output, perform a universal trip and check for permanent DTCs (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR ).

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P2195 (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: P2195-P2198; Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)+ ).

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

  • Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, 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 the No. 1 cylinder*.

    *: The No. 1 cylinder is the cylinder which is farthest from the transaxle.

  • Bank 2 refers to the bank that does not include the No. 1 cylinder.
  • Sensor 1 refers to the sensor closest to the engine assembly.
  • Sensor 2 refers to the sensor farthest away from the engine assembly.
  • Change the fuel injection volume using the Control the Injection Volume function provided in the Active Test and monitor the air fuel ratio sensor output voltage (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: P0136-P0139,P013A,P013C,P0156-P0159; Oxygen Sensor Circuit (Bank 1 Sensor 2)+ ). If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

PROCEDURE

1.

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

(a) Inspect the air fuel ratio sensor (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): AIR FUEL RATIO SENSOR: INSPECTION ).

HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION ).

NG

REPLACE AIR FUEL RATIO SENSOR

OK

2.

CHECK TERMINAL VOLTAGE (+B OF AIR FUEL RATIO SENSOR)

(a) Disconnect the air fuel ratio sensor connectors.

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

B14-2 (+B) - Body ground

Ignition switch ON

11 to 14 V

B13-2 (+B) - Body ground

Ignition switch ON

11 to 14 V

Text in Illustration

*a

Front view of wire harness connector

(to Air Fuel Ratio Sensor)

*b

Bank 1

*c

Bank 2
NG

GO TO STEP 5

OK

3.

CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)

(a) Disconnect the B13 and B14 air fuel ratio sensor connectors.

(b) Disconnect the B1 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

B14-1 (HA1A) - B1-22 (HA1A)

Always

Below 1 Ω

B13-1 (HA2A) - B1-20 (HA2A)

Always

Below 1 Ω

B14-1 (HA1A) or B1-22 (HA1A) - Body ground

Always

10 kΩ or higher

B13-1 (HA2A) or B1-20 (HA2A) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK WHETHER DTC OUTPUT RECURS

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream on.

(c) Clear DTCs (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR ).

(d) Start the engine.

(e) Refer to the confirmation driving pattern.

(f) Read Pending DTCs.

Result

Result

Proceed to

No pending DTC is output

A

Pending DTC P0031, P0032, P0051, P0052, P101D, P103D is output

B
A

CHECK FOR INTERMITTENT PROBLEMS

B

REPLACE ECM

5.

INSPECT A/F HTR RELAY

(a) Inspect the A/F HTR relay (See page 2016 MY Sienna [12/2015 - 08/2016]; 2GR-FE (ENGINE CONTROL): RELAY: ON-VEHICLE INSPECTION+ ).

NG

REPLACE A/F HTR RELAY
OK

6.

CHECK HARNESS AND CONNECTOR (A/F HTR RELAY - AIR FUEL RATIO SENSOR)

(a) Remove the A/F HTR relay.

(b) Disconnect the B13 and B14 air fuel ratio sensor connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Condition

Condition

Specified Condition

3 (A/F HTR relay holder) - B14-2 (+B)

Always

Below 1 Ω

3 (A/F HTR relay holder) - B13-2 (+B)

Always

Below 1 Ω

3 (A/F HTR relay holder) or B14-2 (+B) - Body ground

Always

10 kΩ or higher

3 (A/F HTR relay holder) or B13-2 (+B) - Body ground

Always

10 kΩ or higher
OK

CHECK ECM POWER SOURCE CIRCUIT

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR