P014C
2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P014C A/F Sensor Slow Response - Rich to Lean Bank 1 Sensor 1
DESCRIPTION
HINT
- Refer to DTC P2195 P2195.
- Sensor 1 refers to the sensor mounted in front of the three-way catalytic converter and located near the engine assembly.
- *: Calculated by ECM based on the air fuel ratio sensor output.
MONITOR DESCRIPTION
After the engine is 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 volume 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, DTCs P014C and P014D are stored.
If the time it takes the air fuel ratio sensor output to change is delayed, DTCs P015A and P015B are stored.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
Air Fuel Ratio Sensor (Bank 1) Slow Response (Rich to Lean)
Air Fuel Ratio Sensor (Bank 1) Slow Response (Lean to Rich)
Air Fuel Ratio Sensor (Bank 1) Delayed Response (Rich to Lean)
Air Fuel Ratio Sensor (Bank 1) Delayed Response (Lean to Rich)
MONITOR RESULT
Refer to Checking Monitor Status Mode 6 Data.
CONFIRMATION DRIVING PATTERN
HINT
Performing this confirmation pattern will activate the A/F sensor response monitor.
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
5. Turn the ignition switch off and wait for at least 30 seconds.
6. Turn the ignition switch to ON and turn the Techstream on.
7. Enter the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / O2 Sensor / Details.
8. Check that the monitor item O2 Sensor 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).
9. Start the engine and warm it up (until the engine coolant temperature is 75°C (167°F) or higher) [A].
10. 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.
11. Check that the monitor item O2 Sensor becomes Complete.
HINT
Check the test values on the Techstream by entering the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / O2 Sensor / Details / RL RES RATE B1S1, LR RES RATE B1S1, RL DELAY B1S1, and LR DELAY B1S1.
12. If the monitor item O2 Sensor does not become Complete (if the test values indicated on the Techstream do not change), perform Readiness Monitor Drive Pattern for the A/F sensor and heated oxygen sensor Monitors, Trips, Drive Cycles and Readiness Codes.
13. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
14. 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.
15. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
16. Input the DTC: P014C, P014D, P015A, and P015B.
17. Check the DTC judgment result.
HINT
If the judgment result shows ABNORMAL, the system has a malfunction.
18. If the DTC judgment result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
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 P2195.
INSPECTION PROCEDURE
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.
- 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 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.
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.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read DTCs.
Result
HINT
If any DTCs other than P014C, P014D, P015A or P015B are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) P0031
NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM) P2237
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. INSPECT AIR FUEL RATIO SENSOR
(a) Check that the proper air fuel ratio sensor is installed to the vehicle.
NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.
5. PERFORM CONFIRMATION DRIVING PATTERN
(a) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
NEXT -- Continue to next step.
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.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read pending DTCs.
Result
B -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
A -- Continue to next step.
7. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the air fuel ratio sensor Removal.
NEXT -- Continue to next step.
8. PERFORM CONFIRMATION DRIVING PATTERN
(a) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
NEXT -- Continue to next step.
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.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read pending DTCs.
Result
B -- CHECK ENGINE TO DETERMINE CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO P0171
A -- END