Toyota Venza: Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2) (P0037,P0038,P0141,P102D)

Toyota Venza Service Manual / 1ar-fe Engine Control / Sfi System / Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2) (P0037,P0038,P0141,P102D)

DESCRIPTION

Refer to DTC P0136 (See page ).

HINT:

When any of these DTCs are stored, the ECM enters fail-safe mode. The ECM turns off the heated oxygen 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 heated oxygen sensor heater circuit uses a relay on the +B side of the circuit.

DTC No.	DTC Detection Condition	Trouble Area
P0037	The heater current less than the specified value while the heater is operating (1 trip detection logic).	Open in heated oxygen sensor (bank 1 sensor 2) heater circuit Heated oxygen sensor (bank 1 sensor 2) EFI MAIN No. 2 relay ECM
P0038	Heated oxygen sensor heater current reaches high limit (1 trip detection logic).	Short in heated oxygen sensor (bank 1 sensor 2) heater circuit Heated oxygen sensor (bank 1 sensor 2) EFI MAIN No. 2 relay ECM
P0141	The cumulative heater resistance correction value exceeds the threshold (2 trip detection logic).	Open or short in heated oxygen sensor (bank 1 sensor 2) heater circuit Heated oxygen sensor (bank 1 sensor 2) heater EFI MAIN No. 2 relay ECM
P102D	The heater current is higher than the specified value while the heater is not operating (1 trip detection logic).	ECM

MONITOR DESCRIPTION

The sensing portion of the heated oxygen sensor has a zirconia element which is used to detect the oxygen concentration in the exhaust gas. If the zirconia element is at the appropriate temperature, and the difference between the oxygen concentrations surrounding the inside and outside surfaces of the sensor is large, the zirconia element generates voltage signals. In order to increase the oxygen concentration detecting capacity of the zirconia element, the ECM supplements the heat from the exhaust with heat from a heating element inside the sensor.

Heated Oxygen Sensor Heater Range Check (P0037, P0038 and P102D):

The ECM monitors the current applied to the heated oxygen sensor heater to check the heater for malfunctions.
If the heater current is outside the normal range, the signal transmitted by the heated oxygen sensor becomes inaccurate. When the current in the heated oxygen sensor heater is outside the normal operating range, the ECM interprets this as a malfunction in the sensor heater and stores a DTC.

Heated Oxygen Sensor Heater Performance (P0141):

After the accumulated heater ON time exceeds 100 seconds, the ECM calculates the heater resistance using battery voltage and the current applied to the heater. If the resistance is above the threshold value, the ECM determines that there is a malfunction in the heated oxygen sensor heater and stores DTC P0141.

MONITOR STRATEGY

Related DTCs	P0037: Heated Oxygen Sensor Heater (Bank 1 Sensor 2) range check (Low Current) P0038: Heated Oxygen Sensor Heater (Bank 1 Sensor 2) range check (High Current) P0141: Heated Oxygen Sensor Heater (Bank 1 Sensor 2) Performance P102D: Heated Oxygen Sensor Heater (Bank 1 Sensor 2) Performance
Required Sensors/Components (Main)	Heated oxygen sensor heater (bank 1 sensor 2)
Required Sensors/Components (Related)	-
Frequency of Operation	Continuous: P0037, P0038, P102D Once per driving cycle: P0141
Duration	0.5 seconds: P0037 Within 3 seconds: P0038 10 seconds: P0141 0.5 seconds: P102D
MIL Operation	Immediate: P0037, P0038, P102D 2 driving cycles: P0141
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

P0037 (Case 1)

Monitor runs whenever the following DTCs are not stored	None
All of the following conditions are met	-
Battery voltage	10.5 V or higher
Engine	Running
Starter	OFF
Catalyst active air fuel ratio control	Not operating
Time after heater on	10 seconds or more
Learned heater off current operation	Completed
Learned heater off current operation	Succeeded
Heated oxygen sensor heater high current fail (P0038)	Not detected
Heater on current - learned heater off current	0.3 A or less
Command to heater output	ON

P0037 (Case 2)

Monitor runs whenever the following DTCs are not stored	None
All of the following conditions are met	-
Battery voltage	10.5 V or higher
Engine	Running
Starter	OFF
Catalyst active air fuel ratio control	Not operating
Time after heater on	10 seconds or more
Learned heater off current operation	Completed
Heater off current	Higher than 3.5 A
Heater current detected by heater monitor IC	4 A or higher
Heated oxygen sensor heater high current fail (P0038)	Not detected

P0038

Monitor runs whenever the following DTCs are not stored	None
All of the following conditions are met	-
Battery voltage	10.5 V or higher
Engine	Running
Starter	OFF
Catalyst active air fuel ratio control	Not operating
Time after heater on	10 seconds or more
Learned heater off current operation	Completed
Heater current detected by heater monitor IC	4 A or higher
Command to heater output	ON

P0141

Monitor runs whenever the following DTCs are not stored	None
All of the following conditions are met	-
Heated oxygen sensor heater circuit fail (P0037, P0038 and P101D)	Not detected
Battery voltage	10.5 V or higher
Fuel cut	OFF
Time after fuel cut on to off	30 seconds or more
Accumulated heater on time	100 seconds or more
Learned heater off current operation	Completed
Duration that rear heated oxygen sensor impedance is less than 15 kΩ	2 seconds or more

P102D

Monitor runs whenever the following DTCs are not stored	None
All of the following conditions are met	-
Battery voltage	10.5 V or higher
Engine	Running
Starter	OFF
Catalyst active air fuel ratio control	Not operating
Time after heater on	10 seconds or more
Learned heater off current operation	Completed
Oxygen sensor heater low current fail (P0037)	Not detected
Oxygen sensor heater high current fail (P0038)	Not detected
Command to heater output	OFF
Heater off current	Higher than 3.5 A
Heater current detected by heater monitor IC	4 A or higher

TYPICAL MALFUNCTION THRESHOLDS

P0037 (Case 1)

Heater on current - Learned heater off current

0.3 A or less

P0037 (Case 2)

Heater on current

1 A or less

P0038

Heater current detected by heater monitor IC	4 A or higher
Command to heater output	ON

P0141

Heater resistance

Varies with sensor element temperature (Example: Higher than 23 Ω)

P102D

Heater on current

Higher than 1 A

MONITOR RESULT

Refer to Checking Monitor Status (See page ).

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: P0037, P0038, P0141 or P102D.

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

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.

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 P0136 (See page ).

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.
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 heated oxygen sensor output voltage (See page ). If the sensor
output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

PROCEDURE

1.	INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE)

(a) Inspect the heated oxygen sensor (See page ).

HINT:

Perform "Inspection After Repair" after replacing the heated oxygen sensor (See page ).

REPLACE HEATED OXYGEN SENSOR

2.	CHECK TERMINAL VOLTAGE (POWER SOURCE)

(a) Disconnect the heated oxygen sensor connector.

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
B57-2 (+B) - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Heated Oxygen Sensor)

GO TO STEP 5

3.	CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)

(a) Disconnect the heated oxygen sensor connector.

(b) Disconnect the ECM connector.

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
B57-1 (HT1B) - B58-41 (HT1B)	Always	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
B57-1 (HT1B) or B58-41 (HT1B) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK WHETHER DTC OUTPUT RECURS (DTC P0037, P0038, P0141 OR P102D)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Clear the DTCs (See page ).

(e) Turn the ignition switch off and wait for at least 30 seconds.

(f) Allow the vehicle to drive in accordance with the driving pattern described in the Confirmation Driving Pattern.

(g) Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

(h) Read the Pending DTCs.

Result	Proceed to
DTC P0037, P0038, P0141 or P102D is output	A
DTC is not output	B

REPLACE ECM

CHECK FOR INTERMITTENT PROBLEMS

5.	INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (EFI MAIN NO. 2 RELAY)

(a) Inspect the EFI MAIN No. 2 relay (See page ).

REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY

6.	CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - EFI MAIN NO. 2 RELAY)

(a) Disconnect the heated oxygen sensor connector.

(b) Remove the engine room junction block assembly from the engine room relay block.

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
B57-2 (+B) - 1F-9	Always	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
B57-2 (+B) or 1F-9 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI MAIN NO. 2 RELAY)

REPAIR OR REPLACE HARNESS OR CONNECTOR

Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1) (P0031,P0032,P101D)

DESCRIPTION Refer to DTC P2195 (See page ). HINT: When any of these DTCs is stored, the ECM enters fail-safe mode. The ECM turns off the air fuel ratio sensor heater in fail-safe mode. ...

Mass Air Flow Circuit Range / Performance Problem (P0101)

DESCRIPTION Refer to DTC P0102 (See page ). DTC No. DTC Detection Condition Trouble Area P0101 All of the following conditions are met ( ...

Other materials about Toyota Venza:

Differential Mount Cushion
Components COMPONENTS ILLUSTRATION Installation INSTALLATION PROCEDURE 1. INSTALL REAR NO. 1 DIFFERENTIAL MOUNT CUSHION (a) Using SST, install a new rear No. 1 differential mount cushion. Text in Illustration *1 Protrusion ...

Reassembly
REASSEMBLY PROCEDURE 1. INSTALL GENERATOR ROTOR ASSEMBLY (a) Place the drive end frame on the clutch pulley. (b) Install the generator rotor assembly to the drive end frame. 2. INSTALL GENERATOR CL ...

System Description
SYSTEM DESCRIPTION 1. NAVIGATION SYSTEM OUTLINE (a) Vehicle position tracking methods It is essential that the navigation system correctly tracks the current vehicle position and displays it on the map. There are 2 methods to track the current vehicle p ...