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
-
Connect the Techstream to the DLC3.
-
Turn the ignition switch to ON and turn the Techstream on.
-
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page
).
-
Turn the ignition switch off and wait for at least 30 seconds.
-
Turn the ignition switch to ON and turn the Techstream on [A].
-
Start the engine and idle it for 5 minutes or more [B].
-
With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of 3000 rpm for 1 minute [C].
-
Idle the engine for 5 minutes or more [D].
-
Enter the following menus: Powertrain / Engine / Trouble Codes [E].
-
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.
-
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
-
Input the DTC: P0031, P0032, P0051, P0052, P101D or P103D.
-
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
|
-
If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [E] again.
-
If no pending DTC is output, perform a universal trip and check for permanent DTCs (See page
).
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
).
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
1.
|
INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
|
(a) Inspect the air fuel ratio sensor (See page
).
HINT:
Perform "Inspection After Repair" after replacing the air fuel ratio sensor (See page
).
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
|
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
).
(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) Inspect the A/F HTR relay (See page
).
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
|
NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR
|
|