Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: O2 Sensor Slow Response - Rich to Lean Bank 1 Sensor 1 (P014C00-P014F00,P015A00-P015D00)

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Engine & Hybrid System / 2gr-fks (engine Control) / Sfi System / O2 Sensor Slow Response - Rich to Lean Bank 1 Sensor 1 (P014C00-P014F00,P015A00-P015D00)

DESCRIPTION

Refer to DTC P219519.

Click here

HINT:

Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P014C00	O2 Sensor Slow Response - Rich to Lean Bank 1 Sensor 1	The "Rich to Lean response rate deterioration level*" value is standard or less (2 trip detection logic).	Air fuel ratio sensor (bank 1 sensor 1) Air fuel ratio sensor (bank 1 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P014C
P014D00	O2 Sensor Slow Response - Lean to Rich Bank 1 Sensor 1	The "Lean to Rich response rate deterioration level*" value is standard or more (2 trip detection logic).	Air fuel ratio sensor (bank 1 sensor 1) Air fuel ratio sensor (bank 1 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P014D
P014E00	O2 Sensor Slow Response - Rich to Lean Bank 2 Sensor 1	The "Rich to Lean response rate deterioration level*" value is standard or less (2 trip detection logic).	Air fuel ratio sensor (bank 2 sensor 1) Air fuel ratio sensor (bank 2 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P014E
P014F00	O2 Sensor Slow Response - Lean to Rich Bank 2 Sensor 1	The "Lean to Rich response rate deterioration level*" value is standard or more (2 trip detection logic).	Air fuel ratio sensor (bank 2 sensor 1) Air fuel ratio sensor (bank 2 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P014F
P015A00	O2 Sensor Delayed Response - Rich to Lean Bank 1 Sensor 1	The "Rich to Lean delay level*" value is standard or more (2 trip detection logic).	Air fuel ratio sensor (bank 1 sensor 1) Air fuel ratio sensor (bank 1 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P015A
P015B00	O2 Sensor Delayed Response - Lean to Rich Bank 1 Sensor 1	The "Lean to Rich delay level*" value is standard or more (2 trip detection logic).	Air fuel ratio sensor (bank 1 sensor 1) Air fuel ratio sensor (bank 1 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P015B
P015C00	O2 Sensor Delayed Response - Rich to Lean Bank 2 Sensor 1	The "Rich to Lean delay level*" value is standard or more (2 trip detection logic).	Air fuel ratio sensor (bank 2 sensor 1) Air fuel ratio sensor (bank 2 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P015C
P015D00	O2 Sensor Delayed Response - Lean to Rich Bank 2 Sensor 1	The "Lean to Rich delay level*" value is standard or more (2 trip detection logic).	Air fuel ratio sensor (bank 2 sensor 1) Air fuel ratio sensor (bank 2 sensor 1) heater ECM	Comes on	DTC stored	SAE Code: P015D

*: 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 30 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 P014C00, P014D00, P014E00 and P014F00 are output.

If the air fuel ratio sensor output timing is delayed, DTC P015A00, P015B00, P015C00 and P015D00 are output.

MONITOR STRATEGY

Related DTCs	P014C: Air fuel ratio sensor (bank 1) response rate (rich to lean response rate) P014D: Air fuel ratio sensor (bank 1) response rate (lean to rich response rate) P014E: Air fuel ratio sensor (bank 2) response rate (rich to lean response rate) P014F: Air fuel ratio sensor (bank 2) response rate (lean to rich response rate) P015A: Air fuel ratio sensor (bank 1) response rate (rich to lean delay) P015B: Air fuel ratio sensor (bank 1) response rate (lean to rich delay) P015C: Air fuel ratio sensor (bank 2) response rate (rich to lean delay) P015D: Air fuel ratio sensor (bank 2) 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	P0010, P0020 (VVT oil control solenoid bank 1, 2) P0011, P0021 (VVT system bank 1, 2 - advance) P0012, P0022 (VVT system bank 1, 2 - retard) P0013, P0023 (Exhaust VVT oil control solenoid bank 1, 2) P0014, P0024 (Exhaust VVT system bank 1, 2 - advance) P0015, P0025 (Exhaust VVT system bank 1, 2 - retard) P0016, P0018 (VVT system bank 1, 2 - misalignment) P0017, P0019 (Exhaust VVT system bank 1, 2 - misalignment) P0031, P0032, P0051, P0052, P101D, P103D (Air fuel ratio sensor heater) P0037, P0038, P0057, P0058, P0141, P0161, P102D, P105D (Heated oxygen sensor heater) P0087, P0088, P0191, P0192, P0193 (Fuel pressure sensor (for high pressure side)) P0101, P0102, P0103 (Mass air flow meter) P0111, P0112, P0113 (Intake air temperature sensor) P0116, P0117, P0118 (Engine coolant temperature sensor) P011B (Engine coolant temperature/intake air temperature sensor correlation) P0121, P0122, P0123, P0222, P0223, P2135 (Throttle position sensor) P0125 (Insufficient coolant temperature for closed loop fuel control) P0128 (Thermostat) P0136, P0137, P0138, P0139, P013A, P013C, P0156, P0157, P0158, P0159, P0607 (Heated Oxygen Sensor) P0171, P0172, P0174, P0175 (Fuel system) P0201, P0202, P0203, P0204, P0205, P0206, P062D, P21CF, P21D0, P21D1, P21D2, P21D3, P21D4 (Fuel injector) P0300 - P0306 (Misfire) P0327, P0328, P0332, P0333 (Knock control sensor) P0335, P0337, P0338 (Crankshaft position sensor) P0340, P0342, P0343, P0345, P0347, P0348 (VVT sensor) P0365, P0367, P0368, P0390, P0392, P0393 (Exhaust VVT sensor) P0441 (EVAP system) P0500 (Vehicle speed sensor) P0657, P2102, P2103, P2111, P2112, P2119 (Throttle actuator) P107B, P107C, P107D (Fuel pressure sensor (for low pressure side)) P11EA, P11EB, P11EC, P11ED, P11EE, P11EF, P11F0, P11F1, P219A, P219B, P219C, P219D, P219E, P219F, P21A0, P21A1 (Air-fuel ratio imbalance) P1235 (High pressure fuel pump circuit)
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	1100 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 85%
Shift position	2nd or more
Catalyst monitor	Not yet
Mass air flow	4 gm/sec or higher, and less than 14 gm/sec

TYPICAL MALFUNCTION THRESHOLDS

P014C and P014E: Air Fuel Ratio Sensor (Bank 1) Response Rate (Rich to Lean Response Rate)

Rich to Lean response rate deterioration level

0.0545 V or less

P014C and P014E: Air Fuel Ratio Sensor (Bank 2) Response Rate (Rich to Lean Response Rate)

Rich to Lean response rate deterioration level

0.0545 V or less

P014D and P014F: Air Fuel Ratio Sensor (Bank 1) Response Rate (Lean to Rich Response Rate)

Lean to Rich response rate deterioration level

-0.0615 V or higher

P014D and P014F: Air Fuel Ratio Sensor (Bank 2) Response Rate (Lean to Rich Response Rate)

Lean to Rich response rate deterioration level

-0.0615 V or higher

P015A and P015C: Air Fuel Ratio Sensor (Bank 1) Response Rate (Rich to Lean Delay)

Rich to Lean delay level

376.83 ms or more

P015A and P015C: Air Fuel Ratio Sensor (Bank 2) Response Rate (Rich to Lean Delay)

Rich to Lean delay level

376.83 ms or more

P015B and P015D: Air Fuel Ratio Sensor (Bank 1) Response Rate (Lean to Rich Delay)

Lean to Rich delay level

376.83 ms or more

P015B and P015D: Air Fuel Ratio Sensor (Bank 2) Response Rate (Lean to Rich Delay)

Lean to Rich delay level

376.83 ms or more

MONITOR RESULT

Refer to detailed information in Checking Monitor Status.

Click here

P014C: O2 Sensor / RL RESPONSE RATE B1S1

Monitor ID	Test ID	Scaling	Unit	Description
$01	$93	Multiply by 0.00012	V	Rich to Lean response rate deterioration level

P014D: O2 Sensor / LR RESPONSE RATE B1S1

Monitor ID	Test ID	Scaling	Unit	Description
$01	$94	Multiply by 0.00012	V	Lean to Rich response rate deterioration level

P014E: O2 Sensor / RL RESPONSE RATE B2S1

Monitor ID	Test ID	Scaling	Unit	Description
$05	$93	Multiply by 0.00012	V	Rich to Lean response rate deterioration level

P014F: O2 Sensor / LR RESPONSE RATE B2S1

Monitor ID	Test ID	Scaling	Unit	Description
$05	$94	Multiply by 0.00012	V	Lean to Rich response rate deterioration level

P015A: O2 Sensor / RL DELAY B1S1

Monitor ID	Test ID	Scaling	Unit	Description
$01	$95	Multiply by 0.001	Second	Rich to Lean delay level

P015B: O2 Sensor / LR DELAY B1S1

Monitor ID	Test ID	Scaling	Unit	Description
$01	$96	Multiply by 0.001	Second	Lean to Rich delay level

P015C: O2 Sensor / RL DELAY B2S1

Monitor ID	Test ID	Scaling	Unit	Description
$05	$95	Multiply by 0.001	Second	Rich to Lean delay level

P015D: O2 Sensor / LR DELAY B2S1

Monitor ID	Test ID	Scaling	Unit	Description
$05	$96	Multiply by 0.001	Second	Lean to Rich delay level

CONFIRMATION DRIVING PATTERN

HINT:

Performing this confirmation pattern will activate the air fuel ratio sensor response monitor.
After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG).
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 RESPONSE RATE B1S1, LR RESPONSE RATE B1S1, RL DELAY B1S1, LR DELAY B1S1, RL RESPONSE RATE B2S1, LR RESPONSE RATE B2S1, RL DELAY B2S1 and LR DELAY B2S1 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 RESPONSE RATE B1S1, LR RESPONSE RATE B1S1, RL DELAY B1S1, LR DELAY B1S1, RL RESPONSE RATE B2S1, LR RESPONSE RATE B2S1, RL DELAY B2S1 and LR DELAY B2S1.
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.
Click here
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: P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 or P015D00.

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

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
[A] to [C]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

WIRING DIAGRAM

Refer to DTC P219519.

Click here

CAUTION / NOTICE / HINT

NOTICE:

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

HINT:

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.
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.
Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.
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 moving or stationary, 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.

PROCEDURE

1.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 OR P015D00)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

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

(e) Read the DTCs.

Powertrain > Engine > Trouble Codes

Result	Proceed to
DTC P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 or P015D00 is output	A
DTC P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 or P015D00 and other DTCs are output	B

HINT:

If any DTCs other than P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 or P015D00 are output, troubleshoot those DTCs first.

GO TO DTC CHART

2.	INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

(a) Inspect the air fuel ratio sensor.

Click here

HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor.

Click here

REPLACE AIR FUEL RATIO SENSOR

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

(a) Disconnect the air fuel ratio sensor connector.

(b) Disconnect the ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D24-1 (HA1A) - D2-52 (HA1A)	Always	Below 1 Ω
D24-3 (A1A+) - D2-125 (A1A+)	Always	Below 1 Ω
D24-4 (A1A-) - D2-126 (A1A-)	Always	Below 1 Ω
D23-1 (HA2A) - D2-17 (HA2A)	Always	Below 1 Ω
D23-3 (A2A+) - D2-123 (A2A+)	Always	Below 1 Ω
D23-4 (A2A-) - D2-124 (A2A-)	Always	Below 1 Ω
D24-1 (HA1A) or D2-52 (HA1A) - Body ground and other terminals	Always	10 kΩ or higher
D24-3 (A1A+) or D2-125 (A1A+) - Body ground and other terminals	Always	10 kΩ or higher
D24-4 (A1A-) or D2-126 (A1A-) - Body ground and other terminals	Always	10 kΩ or higher
D23-1 (HA2A) or D2-17 (HA2A) - Body ground and other terminals	Always	10 kΩ or higher
D23-3 (A2A+) or D2-123 (A2A+) - Body ground and other terminals	Always	10 kΩ or higher
D23-4 (A2A-) or D2-124 (A2A-) - Body ground and other terminals	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK 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.

Click here

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 P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 OR P015D00)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

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

(e) Read the pending DTCs.

Powertrain > Engine > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTC P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 or P015D00 is output	B

CHECK FOR INTERMITTENT PROBLEMS

7.	REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor.

Click here

HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor.

Click here

8.	PERFORM CONFIRMATION DRIVING PATTERN

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

9.	CHECK WHETHER DTC OUTPUT RECURS (DTC P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 OR P015D00)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

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

(e) Read the pending DTCs.

Powertrain > Engine > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTC P014C00, P014D00, P014E00, P014F00, P015A00, P015B00, P015C00 or P015D00 is output	B

END

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