P2195
2GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2195-P2198: Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)
DESCRIPTION
HINT
Although the DTC titles include oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
The A/F 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 A/F sensor malfunctions, the ECM is unable to control the air-fuel ratio accurately.
The A/F sensor is the planar type and is integrated with the 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 though the alumina, 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 TWC is used. For the most efficient use of the TWC, 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 A/F sensor is the current output element, a current is converted to a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors will show a constant voltage.
HINT
- When any of these DTCs are set, check the A/F sensor output voltage by entering the following menus on the Techstream: Powertrain / Engine and ECT / Data List / AFS Voltage B1S1 or AFS Voltage B2S1.
- Short-term fuel trim values can also be read using the Techstream.
- The ECM regulates the voltages at the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a constant level. Therefore, the A/F sensor output voltage cannot be confirmed without using the Techstream.
- If an A/F sensor malfunction is detected, the ECM sets a DTC.
MONITOR DESCRIPTION
Sensor voltage detection monitor
Under the air-fuel ratio feedback control, if the A/F sensor output voltage indicates rich or lean for a certain period of time, the ECM determines that there is a malfunction in the A/F sensor. The ECM illuminates the MIL and sets a DTC.
Example:
If the A/F sensor output voltage is less than 2.8 V (very rich condition) for 5 seconds, despite the rear HO2 sensor output voltage being below 0.59 V, the ECM sets DTC P2196 or P2198. Alternatively, if the A/F sensor output voltage is more than 3.8 V (very lean condition) for 5 seconds, despite the rear HO2 sensor output voltage being 0.21 V or more, DTC P2195 or P2197 is set.
Sensor current detection monitor
A rich air-fuel mixture causes a low A/F sensor current, and a lean air-fuel mixture causes a high A/F sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high during deceleration with the throttle valve fully closed. The ECM monitors the A/F sensor current during fuel-cut and detects any abnormal current values.
If the A/F sensor output is 3.6 mA or more for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the A/F sensor and sets DTC P2195 or P2197 (high-side stuck). If the A/F sensor output is less than 0.78 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 or P2198 (low-side stuck).
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
Sensor rationality:
Sensor current:
TYPICAL MALFUNCTION THRESHOLDS
Sensor rationality (Lean side malfunction P2195, P2197):
Sensor rationality (Rich side malfunction P2196, P2198):
Sensor current (High side malfunction P2195, P2197):
Sensor current detection monitor (Low side malfunction P2196, P2198):
MONITOR RESULT
Refer to CHECKING MONITOR STATUS Mode 6 Data.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.
1. Put the engine in inspection mode Inspection Mode Procedure.
2. Connect the Techstream to the DLC3.
3. Turn the power switch on (READY).
4. Turn the Techstream on.
5. Clear the DTCs DTC Check / Clear.
6. Warm up the engine until the engine coolant temperature reaches 75°C (167°F) or higher.
7. Drive the vehicle at between 37 mph (60 km/h) and 75 mph (120 km/h) for 10 minutes or more.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
8. Repeat the following drive pattern 3 times or more:
- Drive the vehicle at 75 mph (120 km/h).
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
- Release the accelerator pedal and stop the vehicle.
9. Check the pending DTC.
INSPECTION PROCEDURE
HINT
Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor function provided in the Active Test. The Control the Injection Volume for A/F Sensor function can help to determine whether the Air-fuel Ratio (A/F) sensor, Heated Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using the Techstream.
1. Put the engine in inspection mode Inspection Mode Procedure.
2. Connect the Techstream to the DLC3.
3. Turn the Techstream on.
4. Warm up the engine.
5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
6. Perform the Control the Injection Volume for A/F Sensor operation with the engine in an idling condition (press the RIGHT or LEFT button to change the injection volume).
7. Monitor the output voltages of the A/F and HO2 sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.
HINT
- The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- Each sensor reacts in accordance with increases in the injection volume.
NOTICE:
The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the HO2S (sensor 2) output has a maximum output delay of 20 seconds.
- Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
- To display the graph, enter the following menus on the Techstream: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2; then press the graph button on the Data List view.
HINT
- DTCs P2195 and P2196 indicate malfunctions related to the bank 1 A/F sensor circuit.
- DTCs P2197 and P2198 indicate malfunctions related to the bank 2 A/F sensor circuit.
- Bank 1 refers to the bank that includes the No. 1 cylinder.
- Bank 2 refers to the bank that does not include the No. 1 cylinder.
- 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 Freeze Frame Data.
- A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would cause the engine to run rich.
- A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that would cause the engine to run lean.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, 2197 OR P2198)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs.
Result:
HINT
If any DTCs relating to the A/F sensor (DTCs for the A/F sensor heater or A/F sensor admittance) are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (TEST VALUE OF A/F SENSOR)
(a) Put the engine in inspection mode Inspection Mode Procedure.
(b) Connect the Techstream to the DLC3.
(c) Turn the Techstream on.
(d) Clear the DTCs DTC Check / Clear.
(e) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(f) Enter the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / O2 Sensor / Current.
(g) Check that the status of O2 Sensor is Complete. If the status is still Incomplete, perform the driving pattern increasing the vehicle speed and using the second gear to decelerate the vehicle.
(h) Enter the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / O2 Sensor / Details / RANGE B1S1 or RANGE B2S1.
(i) Check the test value of the A/F sensor output current during fuel cut.
Result:
B -- REPLACE AIR FUEL RATIO SENSOR
A -- Continue to next step.
3. READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF A/F SENSOR)
(a) Put the engine in inspection mode Inspection Mode Procedure.
(b) Connect the Techstream to the DLC3.
(c) Start the engine.
(d) Turn the Techstream on.
(e) Warm up the A/F sensor at an engine speed of 2500 rpm for 90 seconds.
(f) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Voltage B1S1 or AFS Voltage B2S1 and Engine Speed, then press the Record button.
(g) Check the A/F sensor voltage three times, when the engine is in each of the following conditions:
(1) While idling (check for at least 30 seconds) (Step "A").
(2) Fully depress the accelerator pedal and run the engine at 2500 rpm (Step "B").
(3) Accelerator pedal released (Step "C").
Standard voltage:
HINT
- For more information, see the diagrams below.
- If the output voltage of the A/F sensor remains at approximately 3.3 V (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have an open circuit. (This will also happen if the A/F sensor heater has an open circuit.)
- If the output voltage of the A/F sensor remains at either approximately 3.8 V or more, or 2.8 V or less (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have a short circuit.
- The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and results in a momentary increase in the A/F sensor output voltage.
- When the vehicle is driven:
The output voltage of the A/F sensor may be below 2.8 V during fuel enrichment. For the vehicle, this translates to a sudden increase in speed with the accelerator pedal fully depressed when trying to overtake another vehicle. The A/F sensor is functioning normally.
- The A/F sensor is a current output element; therefore, the current is converted into a voltage inside the ECM. Measuring the voltage at the connectors of the A/F sensor or ECM will show a constant voltage result.
NG -- INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
OK -- Continue to next step.
4. PERFORM CONFIRMATION DRIVING PATTERN
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTC DTC Check / Clear.
(e) Turn the power switch off and wait for 30 seconds or more.
(f) Turn the power switch on (IG) and turn the Techstream on.
(g) Put the engine in inspection mode Inspection Mode Procedure.
(h) Start the engine and warm it up.
(i) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
NEXT -- Continue to next step.
5. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(b) Input the DTC: P2195, P2196, P2197 or P2198.
(c) Check the DTC judgment result.
Result:
B -- CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
A -- Continue to next step.
6. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the A/F sensor Removal.
NEXT -- Continue to next step.
7. PERFORM CONFIRMATION DRIVING PATTERN
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTC DTC Check / Clear.
(e) Turn the power switch off and wait for 30 seconds or more.
(f) Turn the power switch on (IG) and turn the Techstream on.
(g) Put the engine in inspection mode Inspection Mode Procedure.
(h) Start the engine and warm it up.
(i) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(b) Input the DTC: P2195, P2196, P2197 or P2198.
(c) Check the DTC judgment result.
Result:
B -- REPLACE ECM Removal
A -- END
9. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
(a) Has the vehicle run out of fuel in the past?
NO -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
YES -- DTC CAUSED BY RUNNING OUT OF FUEL
10. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) P0031
NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
(a) Disconnect the E74 or E70 A/F sensor connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage between the terminals of the E74 or E70 A/F sensor connector and body ground.
Standard voltage:
(d) Turn the power switch off.
(e) Disconnect the E83 ECM connector.
(f) Measure the resistance.
Standard resistance (Check for open):
Standard resistance (Check for short):
(g) Reconnect the ECM connector.
(h) Reconnect the A/F sensor connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
12. CHECK AIR INDUCTION SYSTEM
(a) Check the air induction system for vacuum leakage.
OK:
No leakage from air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.
13. CHECK FUEL PRESSURE (LOW PRESSURE SIDE)
(a) Check the fuel pressure (low pressure side) Testing and Inspection.
NG -- REPAIR OR REPLACE FUEL SYSTEM (LOW PRESSURE SIDE)
OK -- Continue to next step.
14. CHECK FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION)
(a) Check the fuel injector injection (for port injection) (whether fuel volume is high or low, and whether injection pattern is poor) Fuel Injector (for Port Injection).
NG -- REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION) Removal
OK -- Continue to next step.
15. CHECK FUEL PRESSURE (HIGH PRESSURE SIDE)
(a) Check the fuel pressure (high pressure side) Testing and Inspection.
NG -- REPAIR OR REPLACE FUEL SYSTEM (HIGH PRESSURE SIDE)
OK -- Continue to next step.
16. CHECK FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION)
(a) Check the fuel injector (for direct injection) Fuel Injector (for Direct Injection).
NG -- REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION) Removal
OK -- Continue to next step.
17. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the A/F sensor Removal.
NEXT -- Continue to next step.
18. PERFORM CONFIRMATION DRIVING PATTERN
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTC DTC Check / Clear.
(e) Turn the power switch off and wait for 30 seconds or more.
(f) Turn the power switch on (IG) and turn the Techstream on.
(g) Put the engine in inspection mode Inspection Mode Procedure.
(h) Start the engine and warm it up.
(i) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
NEXT -- Continue to next step.
19. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(b) Input the DTC: P2195, P2196, P2197 or P2198.
(c) Check the DTC judgment result.
Result:
B -- REPLACE ECM Removal
A -- END