P2197
1GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2195: Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)
DTC P2195 - Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)
DTC P2196 - Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1)
DTC P2197 - Oxygen (A/F) Sensor Signal Stuck Lean (Bank 2 Sensor 1)
DTC P2198 - Oxygen (A/F) Sensor Signal Stuck Rich (Bank 2 Sensor 1)
CAUTION / NOTICE / HINT
DESCRIPTION
HINT:
- Although the DTC titles say oxygen sensor, these DTCs relate to the Air Fuel Ratio (A/F) sensor.
- Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.
The A/F 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 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 in to a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors will show a constant voltage.
HINT:
- DTCs P2195 and P2196 indicate malfunctions related to bank 1 A/F sensor circuit.
- DTCs P2197 and P2198 indicate malfunctions related to bank 2 A/F 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 A/F sensor voltage output by selecting the following menu items on a Techstream: Powertrain / Engine and ECT / Data List / A/F Control System / AFS B1S1 or AFS B2S1.
- Short-term fuel trim values can also be read using a 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 voltage output cannot be confirmed without using a Techstream.
- If a 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 voltage output 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 voltage output is less than 2.8 V (very rich condition) and HO2 sensor output voltage falls from 0.59 V or more to less than 0.21 V for 5 seconds, the ECM sets DTC P2196 or P2198. Alternatively, if the A/F sensor voltage output is more than 3.8 V (very lean condition) and HO2 sensor output voltage rises from less than 0.21 V to 0.59 V or more for 5 seconds, 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 1.4mA 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 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 (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.
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the tester ON.
(d) Clear DTCs DTC Check / Clear.
(e) Start the engine, and warm it up until the ECT reaches 75°C (167°F) or higher.
(f) Select the following menu items to check the fuel cut status: Powertrain / Engine and ECT / Data List / All Data / Idle Fuel Cut.
(g) Drive the vehicle at between 38 mph (60 km/h) and 75 mph (120 km/h) for at least 10 minutes.
(h) Change the transmission to 2nd gear.
(i) Drive the vehicle at proper vehicle speed to perform fuel cut operation (refer to the following HINT).
HINT: fuel cut is performed when the following conditions are met:
- Accelerator pedal fully released.
- Engine speed is 2,500 rpm or more (fuel injection returns at 1,000 rpm).
(j) Accelerate the vehicle to 40 mph (64 km/h) or more by depressing the accelerator pedal for at least 10 seconds.
(k) Soon after performing step (j) above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal, in order to execute fuel cut control.
(l) Allow the vehicle to decelerate until the vehicle speed declines to less than 6 mph (10 km/h).
(m) Repeat steps from (h) through (k) above at least 3 times in one driving cycle.
HINT: Completion of all A/F sensor monitors is required to change the value in Test Result.
CAUTION: Strictly observe posted speed limits, traffic laws, and road conditions when performing these drive patterns.
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 a Techstream.
(1) Connect a Techstream to the DLC3.
(2) Start the engine and turn the tester ON.
(3) Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds.
(4) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F sensor.
(5) 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).
(6) Monitor the voltage outputs of the A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS 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:
NOTE: The Air Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) 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 A/F and HO2 sensors.
- To display the graph, select the following menu items on the tester: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F sensor / A/F Control System / AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2, then press the graph button on the Data List view.
HINT:
- Read freeze frame data using a Techstream. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- 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, P2197 OR P2198)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the tester ON.
(d) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(e) Read DTCs.
Result:
HINT: If any DTCs other than P2195, P2196, P2197 or P2198 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (TEST VALUE OF A/F SENSOR)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Clear DTCs DTC Check / Clear.
(d) Allow the vehicle to drive in accordance with the drive pattern described in the CONFIRMATION DRIVING PATTERN.
(e) Select the following menu items on the tester: Powertrain / Engine and ECT / Monitor / O2 Sensor.
(f) Check that the status of O2 Sensor is Complete.
If the status is still Incomplete, drive the vehicle according to the driving pattern again.
(g) Select the following menu items: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details / Range B1S1.
(h) 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) Connect a Techstream to the DLC3.
(b) Start the engine.
(c) Turn the tester ON.
(d) Warm up the Air Fuel Ratio (A/F) sensor at an engine speed of 2,500 rpm for 90 seconds.
(e) Select the following menu items: Powertrain / Engine and ECT / Data List / A/F Control System / AFS Voltage B1S1 and Engine Speed, then press the Record button.
(f) 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)
(2) At an engine speed of approximately 2,500 rpm (without any sudden changes in engine speed)
(3) Raise the engine speed to 4,000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed.
Standard Voltage:
HINT: For more information, see the diagrams below.
HINT:
- 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.
- The ECM must establish a closed throttle valve position learning value to perform fuel cut. If the battery terminal has been reconnected, the vehicle must be driven over 10 mph (16 km/h) to allow the ECM to learn the closed throttle valve position.
- 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
NEXT -- Continue to next step.
5. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch ON and the tester ON.
(c) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes / Pending.
(d) Read DTCs.
Result:
B -- CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
A -- Continue to next step.
6. REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor Removal.
NEXT -- Continue to next step.
7. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
8. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch ON and the tester ON.
(c) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes / Pending.
(d) Read DTCs.
Result:
B -- REPLACE ECM AND PERFORM CONFIRMATION DRIVING PATTERN
A -- Continue to next step.
9. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
NO -- 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
OK -- Continue to next step.
11. INSPECT AIR FUEL RATIO SENSOR HEATER RELAY P0031
NG -- REPLACE AIR FUEL RATIO SENSOR HEATER RELAY
OK -- Continue to next step.
12. CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
(a) Disconnect the B31 or B33 A/F sensor connector.
(b) Turn the ignition switch ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
(d) Turn the ignition switch OFF.
(e) Disconnect the B2 ECM connector.
(f) Measure the resistance according to the value(s) in the table below.
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.
13. CHECK AIR INDUCTION SYSTEM
(a) Check the air induction system for vacuum leak.
OK:
No leak from air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.
14. CHECK FUEL PRESSURE
(a) Check the fuel pressure Testing and Inspection.
NG -- REPAIR OR REPLACE FUEL SYSTEM
OK -- Continue to next step.
15. INSPECT FUEL INJECTOR ASSEMBLY
(a) Check the fuel injector injection (whether fuel volume is high or low, and whether injection pattern is poor).
NG -- REPLACE FUEL INJECTOR ASSEMBLY
OK -- Continue to next step.
16. REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor Removal.
NEXT -- Continue to next step.
17. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
18. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch ON and the tester ON.
(c) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes / Pending.
(d) Read DTCs.
Result:
B -- REPLACE ECM AND PERFORM CONFIRMATION DRIVING PATTERN
A -- Continue to next step.
19. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
NO -- CHECK FOR INTERMITTENT PROBLEMS
YES -- DTC CAUSED BY RUNNING OUT OF FUEL
20. REPLACE AIR FUEL RATIO SENSOR
Replace the air fuel ratio sensor Removal.
NEXT -- Continue to next step.
21. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
22. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes / Pending.
(d) Read DTCs.
Result:
B -- REPLACE ECM
A -- END