P2195
2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2195-P2198: Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)
DESCRIPTION
HINT
* Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.
* Sensor 1 refers to the sensor mounted in front of the three-way catalytic converter and located near the engine assembly.
The air fuel ratio sensor generates a 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 air fuel ratio sensor malfunctions, the ECM is unable to control the air fuel ratio accurately.
The air fuel ratio 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 through the alumina, therefore the sensor activation is accelerated.
A three-way catalytic converter is used in order to convert the carbon monoxide (CO), hydrocarbon, and nitrogen oxides (HOx) into less harmful substances. To allow the three-way catalytic converter to function effectively, it is necessary to keep the air fuel ratio of the engine near the stoichiometric air fuel ratio.
*: Value changes inside the ECM. Since the air fuel ratio sensor is the current output element, a current is converted to a voltage inside the ECM. Any measurements taken at the air fuel ratio sensor or ECM connectors will show a constant voltage.
HINT
* DTCs P2195 and P2196 indicate malfunctions related to the bank 1 air fuel ratio sensor circuit.
* DTCs P2197 and P2198 indicate malfunctions related to the bank 2 air fuel ratio sensor circuit.
* Bank 1 refers to the bank that includes cylinder No. 1.
* Bank 2 refers to the bank that includes cylinder No. 2.
* When any of these DTCs are set, check the air fuel ratio sensor voltage output by selecting the following menu items on the Techstream: Powertrain / Engine and ECT / Data List / A/F Control System / AFS Voltage B1 S1 or AFS Voltage B2 S1.
* 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 air fuel ratio sensor voltage output cannot be confirmed without using the Techstream.
* If an air fuel ratio sensor malfunction is detected, the ECM sets a DTC.
MONITOR DESCRIPTION
Sensor voltage detection monitor
- Under the air fuel ratio feedback control, if the air fuel ratio sensor voltage output indicates rich or lean for a certain period of time, the ECM determines that there is a malfunction in the air fuel ratio sensor. The ECM illuminates the MIL and sets a DTC.
Example:
- If the air fuel ratio sensor voltage output is less than 2.8 V (very rich condition) for 5 seconds, despite the heated oxygen sensor voltage output being less than 0.6 V, the ECM sets DTC P2196. Alternatively, if the air fuel ratio sensor voltage output is more than 3.8 V (very lean condition) for 5 seconds, despite the heated oxygen sensor voltage output being 0.15 V or more, DTC P2195 is set.
Sensor current detection monitor
- A rich air fuel mixture causes a low air fuel ratio sensor current, and a lean air fuel mixture causes a high air fuel ratio 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 air fuel ratio sensor current during fuel-cut and detects any abnormal current values.
- If the air fuel ratio sensor output is 2.2 mA or more for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the air fuel ratio sensor and sets DTC P2195 (high-side stuck). If the air fuel ratio sensor output is 0.8 mA or less for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck).
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
Sensor voltage detection monitor (Lean side malfunction P2195, P2197):
Sensor voltage detection monitor (Rich side malfunction P2196, P2198):
Sensor Current detection monitor P2195, P2196, P2197, P2198
TYPICAL MALFUNCTION THRESHOLDS
Sensor voltage detection monitor (Lean side malfunction P2195, P2197):
Sensor voltage detection monitor (Rich side malfunction P2196, P2198):
Sensor current detection monitor (High side malfunction P2195, P2197):
Sensor current detection monitor (Rich 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. Connect the Techstream to the DLC3.
2. Turn the ignition switch on (IG).
3. Turn the Techstream on.
4. Clear 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 on (IG) and turn the Techstream on.
7. Start the engine and warm it up until the ECT reaches 75°C (167°F) or higher [A].
8. On the Techstream, enter the following menus to check the fuel-cut status: Powertrain / Engine and ECT / Data List / Idle Fuel Cut.
9. Drive the vehicle at a speed between 60 and 120 km/h (38 and 75 mph) for at least 10 minutes [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
10. Shift the transmission to 2nd gear [C].
11. Accelerate the vehicle to 64 km/h (40 mph) or more by depressing the accelerator pedal for at least 10 seconds [D].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
12. Soon after performing step [D] above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal in order to execute fuel-cut control [E].
HINT
Fuel-cut is performed when the following conditions are met:
* Accelerator pedal is fully released.
* Engine speed is 2500 rpm or more (fuel injection returns at 1000 rpm).
13. Allow the vehicle to decelerate until the vehicle speed decreases to less than 10 km/h (6 mph).
14. Repeat steps [C] through [E] above at least 3 times in one driving cycle.
15. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [F].
16. 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.
17. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
18. Input the DTC: P2195, P2196, P2197 or P2198.
19. Check the DTC judgment result.
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 UNKNOWN, perform steps [B] through [F] again.
20. If 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.
INSPECTION PROCEDURE
NOTICE:
Inspect the fuses for circuits related to this system before performing the following 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 sensor, heated oxygen 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.
a. Connect the Techstream to the DLC3.
b. Start the engine and turn the tester on.
c. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
d. Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
e. 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 fuel injection volume).
f. Monitor the voltage outputs of the air fuel ratio and heated oxygen sensors (AFS B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the tester.
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 and decreases in the fuel injection volume.
Standard voltage:
NOTICE:
The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 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 air fuel ratio and heated oxygen sensors.
- To display the graph, select the following menu items on the tester: Control the Injection Volume for A/F Sensor / A/F Control System / AFS Voltage B1 S1 or AFS Voltage B2 S1 and O2S B1 S2 or O2S B2 S2. Then press the graph button on the Data List view.
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 transmission.
* Bank 2 refers to the bank that does not include the No. 1 cylinder.
* 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.
* 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.
* Bank 1 refers to the bank that includes the No. 1 cylinder*.
* *: The No. 1 cylinder is the cylinder which is farthest from the transmission.
* 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.
PROCEDURE
1. CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, P2197 OR P2198)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read DTCs.
Result
HINT
If any DTCs relating to the air fuel ratio sensor (DTCs for the air fuel ratio sensor heater or air fuel ratio sensor admittance) are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
(a) Has the vehicle run out of fuel in the past?
NO -- READ VALUE USING TECHSTREAM (TEST VALUE OF AIR FUEL RATIO SENSOR)
YES -- Continue to next step.
3. PERFORM CONFIRMATION DRIVING PATTERN
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off.
(f) Turn the ignition switch on (IG) and turn the Techstream on.
(g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P2195, P2196, P2197 or P2198.
(k) Check the DTC judgment result.
Result
B -- READ VALUE USING TECHSTREAM (TEST VALUE OF AIR FUEL RATIO SENSOR)
A -- DTC CAUSED BY RUNNING OUT OF FUEL
4. READ VALUE USING TECHSTREAM (TEST VALUE OF AIR FUEL RATIO SENSOR)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on (IG).
(c) Turn the Techstream on.
(d) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Drive the vehicle in accordance with the drive pattern described in 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, drive the vehicle according to the driving pattern again.
(h) Enter the following menus: Powertrain / Engine and ECT / Monitor / Current Monitor / O2 Sensor / Details / RANGE B1 S1 or RANGE B2 S1.
(i) Check the test value of the air fuel ratio sensor output current during fuel-cut.
Result
B -- REPLACE AIR FUEL RATIO SENSOR
A -- Continue to next step.
5. READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)
(a) Connect the Techstream to the DLC3.
(b) Start the engine.
(c) Turn the Techstream on.
(d) Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.
(e) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
(f) Perform the Control the Injection Volume operation with the engine idling.
(g) Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.
HINT
* Change the fuel injection volume within the range of -12.0% to +12.0%. The injection volume can be changed in fine gradations.
* The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
Result
Lean: During the Control the Injection Volume Active Test, the air fuel ratio sensor output voltage (AFS Voltage) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S) is consistently below 0.4 V.
Rich: During the Control the Injection Volume Active Test, the AFS Voltage is consistently below 3.1 V, and the O2S is consistently higher than 0.55 V.
Lean/Rich: During the Control the Injection Volume Active Test, the output voltage of the heated oxygen sensor alternates correctly.
HINT
Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2] Data List / Active List.
B -- REPLACE AIR FUEL RATIO SENSOR
A -- Continue to next step.
6. CHECK INTAKE SYSTEM
(a) Check the intake system for vacuum leaks Intake System.
OK:
No leaks in intake system.
NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.
7. CHECK FOR EXHAUST GAS LEAK
(a) Check for exhaust gas leaks.
OK:
No gas leaks.
NG -- REPAIR OR REPLACE EXHAUST SYSTEM
OK -- Continue to next step.
8. CHECK FUEL PRESSURE
(a) Check the fuel pressure Fuel System.
NG -- CHECK FUEL LINE
OK -- Continue to next step.
9. INSPECT FUEL INJECTOR ASSEMBLY
(a) Check the fuel injector assembly (whether fuel volume is high or low, and whether injector pattern is poor) Testing and Inspection.
NG -- REPLACE FUEL INJECTOR ASSEMBLY Components
OK -- Continue to next step.
10. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the air fuel ratio sensor Components.
NEXT -- Continue to next step.
11. PERFORM CONFIRMATION DRIVING PATTERN
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off.
(f) Turn the ignition switch on (IG) and turn the Techstream on.
(g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P2195, P2196, P2197 or P2198.
(k) Check the DTC judgment result.
Result
B -- END
A -- Continue to next step.
12. REPLACE ECM
(a) Replace the ECM Components.
NEXT -- Continue to next step.
13. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off.
(f) Turn the ignition switch on (IG) and turn the Techstream on.
(g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P2195, P2196, P2197 or P2198.
(k) Check the DTC judgment result.
Result
NEXT -- END
14. REPLACE AIR FUEL RATIO SENSOR
(a) Replace the air fuel ratio sensor Components.
NEXT -- Continue to next step.
15. PERFORM CONFIRMATION DRIVING PATTERN
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(e) Turn the ignition switch off.
(f) Turn the ignition switch on (IG) and turn the Techstream on.
(g) Start the engine and warm it up.
(h) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(i) Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
(j) Input the DTC: P2195, P2196, P2197 or P2198.
(k) Check the DTC judgment result.
Result
B -- REPLACE ECM
A -- END
16. CHECK FUEL LINE
(a) Check the fuel lines for leaks or blockage.
NG -- REPAIR OR REPLACE FUEL LINE
OK -- REPLACE FUEL PUMP