Toyota Venza: A/F Sensor Slow Response - Rich to Lean Bank 1 Sensor 1 (P014C,P014D,P015A,P015B)

Toyota Venza Service Manual / 1ar-fe Engine Control / Sfi System / A/F Sensor Slow Response - Rich to Lean Bank 1 Sensor 1 (P014C,P014D,P015A,P015B)

DESCRIPTION

HINT:

Refer to DTC P2195 (See page ).

DTC No.	DTC Detection Condition	Trouble Area
P014C	The "Rich to Lean response rate deterioration level*" value is standard or less (2 trip detection logic).	Air fuel ratio sensor (sensor 1) Air fuel ratio sensor (sensor 1) heater ECM
P014D	The "Lean to Rich response rate deterioration level*" value is standard or more (2 trip detection logic).
P015A	The "Rich to Lean delay level*" value is standard or more (2 trip detection logic).
P015B	The "Lean to Rich delay level*" value is standard or more (2 trip detection logic).

*: Calculated by ECM based on the air fuel ratio sensor output.

MONITOR DESCRIPTION

After the engine has been warmed up, the ECM carries out air fuel ratio feedback control, and maintains the air fuel ratio at the theoretical level. In addition, after all the preconditions have been met, active air fuel ratio control is carried out for approximately 10 seconds and during active air fuel ratio control, the ECM measures the response of the air fuel ratio sensor by increasing or decreasing a specific injection quantity based on the theoretical air fuel ratio learned during normal air fuel control. The ECM determines whether there is an air fuel ratio sensor malfunction at the mid-point of active air fuel ratio control.

If the air fuel ratio sensor's response ability is reduced, DTC P014C and P014D are output.

If the air fuel ratio sensor output timing is delayed, DTC P015A and P015B are output.

MONITOR STRATEGY

Related DTCs	P014C: Air fuel ratio sensor (sensor 1) response rate (rich to lean response rate) P014D: Air fuel ratio sensor (sensor 1) response rate (lean to rich response rate) P015A: Air fuel ratio sensor (sensor 1) response rate (rich to lean delay) P015B: Air fuel ratio sensor (sensor 1) response rate (lean to rich delay)
Required Sensors/Components (Main)	Air fuel ratio sensor
Required Sensors/Components (Related)	Vehicle speed sensor Crankshaft position sensor
Frequency of Operation	Once per driving cycle
Duration	10 to 15 seconds
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored	None
Active air fuel ratio control	Performing
Active air fuel ratio control is performed when the following conditions are met	-
Battery voltage	11 V or higher
Engine coolant temperature	75°C (167°F) or higher
Idle	Off
Engine speed	1200 rpm or higher, and less than 2500 rpm
Air fuel ratio sensor status	Activated
Fuel-cut	Off
Engine load	10% or higher, and less than 70%
Shift position	2nd or more
Catalyst monitor	Not yet
Mass air flow	4 gm/sec or more, and less than 16 gm/sec

TYPICAL MALFUNCTION THRESHOLDS

P014C: Air Fuel Ratio Sensor (Bank 1) Response Rate (Rich to Lean Response Rate)

Rich to Lean Response rate deterioration level

0.032 V or less

P014D: Air Fuel Ratio Sensor (Bank 1) Response Rate (Lean to Rich Response Rate)

Lean to Rich Response rate deterioration level

-0.0401 V or higher

P015A: Air Fuel Ratio Sensor (Bank 1) Response Rate (Rich to Lean Delay)

Rich to Lean delay level

376.832 ms or more

P015B: Air Fuel Ratio Sensor (Bank 1) Response Rate (Lean to Rich Delay)

Lean to Rich delay level

376.832 ms or more

MONITOR RESULT

Refer to Checking Monitor Status (See page
).

CONFIRMATION DRIVING PATTERN

HINT:

Performing this confirmation pattern will activate the air fuel ratio sensor response monitor.

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the Techstream on.
Enter the following menus: Powertrain / Engine / Monitor / Current Monitor.
Check that O2 Sensor / Current is Incomplete.
HINT:

The test values for the test items RL RES RATE B1S1, LR RES RATE B1S1, RL DELAY B1S1 and LR DELAY B1S1 do not exist in the Detail of O2 Sensor monitor at this time (the initial value of "0.000" is indicated in each test item).
Start the engine and warm it up (until the engine coolant temperature is 75°C (167°F) or higher) [A].
Drive the vehicle at a constant speed between 75 and 100 km/h (47 and 62 mph) for 10 minutes [B].
CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Check that O2 Sensor / Current becomes Complete.
HINT:

Check the test values on the Techstream by entering the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Details / RL RES RATE B1S1, LR RES RATE B1S1, RL DELAY B1S1 and LR DELAY B1S1.
If the monitor item O2 Sensor / Current does not become Complete (if the test values indicated on the Techstream do not change), perform Readiness Monitor Drive Pattern for the air fuel ratio sensor and heated oxygen sensor (See page ).

Enter the following menus: Powertrain / Engine / Trouble Codes [C].
Read the 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: P014C, P014D, P015A or P015B.

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 is INCOMPLETE or N/A, drive the vehicle again under an increased load and then recheck the judgment result.

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.

HINT:

A low air fuel ratio sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.
A high air fuel ratio sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.
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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.

PROCEDURE

1.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P014C, P014D, P015A OR P015B)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

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

(e) Read the DTCs.

Result

Result	Proceed to
DTC P014C, P014D, P015A or P015B is output	A
DTC P014C, P014D, P015A or P015B and other DTCs are output	B

HINT:

If any DTCs other than P014C, P014D, P015A or P015B are output, troubleshoot those DTCs first.

GO TO DTC CHART

2.	INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

REPLACE AIR FUEL RATIO SENSOR

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	INSPECT AIR FUEL RATIO SENSOR

(a) Check that the proper air fuel ratio sensors are installed to the vehicle.

HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (See page ).

REPLACE AIR FUEL RATIO SENSOR

5.	PERFORM CONFIRMATION DRIVING PATTERN

(a) Drive the vehicle according to the Confirmation Driving Pattern.

6.	CHECK WHETHER DTC OUTPUT RECURS (DTC P014C, P014D, P015A OR P015B)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

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

(e) Read the pending DTCs.

Result

Result	Proceed to
DTC P014C, P014D, P015A or P015B are output	A
DTC is not output	B

CHECK FOR INTERMITTENT PROBLEMS

7.	REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor (See page ).

HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (See page ).

8.	PERFORM CONFIRMATION DRIVING PATTERN

(a) Drive the vehicle according to the Confirmation Driving Pattern.

9.	CHECK WHETHER DTC OUTPUT RECURS (DTC P014C, P014D, P015A OR P015B)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

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

(e) Read the pending DTCs.

Result

Result	Proceed to
DTC is not output	A
DTC P014C, P014D, P015A or P015B are output	B

END

CHECK ENGINE TO DETERMINE CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO

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