P2197
2GR-FSE 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)
DESCRIPTION
HINT:
- Although the DTC titles include 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 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:
- 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 includes the No. 2 cylinder.
- 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 B1 S1 or AFS 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 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 15 seconds, despite the rear HO2 sensor output voltage being less than 0.6 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor output voltage is more than 3.8 V (very lean condition) for 15 seconds, despite the rear HO2 sensor output voltage being 0.15 V or more, DTC P2195 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 (high-side stuck). If the A/F sensor output is less than 1.0 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck).
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
Sensor voltage detection monitor (Lean side malfunction P2195, P2197):
Sensor voltage detection monitor (Rich side malfunction P2196, P2198):
Sensor current detection monitor (High and low side malfunction P2195, P2196, P2197 and 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.
1 Connect the Techstream to the DLC3.
2 Turn the power switch on (READY).
3 Turn the Techstream on.
4 Clear the DTCs DTC Check / Clear.
5 Warm up the engine until the engine coolant temperature reaches 75°C (167°F) or higher.
6 Drive the vehicle at between 38 mph (60 km/h) and 75 mph (120 km/h) for 10 minutes or more.
7 Repeat the following drive pattern 3 times or more:
- Drive the vehicle at 75 mph (120 km/h).
- Release the accelerator pedal and stop the vehicle.
8 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 B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2) 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.
NOTE: 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 B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2; then press the graph button on the Data List view.
HINT:
- 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 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
(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) Allow the vehicle to drive in accordance with the driving pattern described in the CONFIRMATION DRIVING PATTERN.
(f) Enter the following menus: Powertrain / Engine and ECT / Monitor / O2S Sensor.
(g) Check the status of O2 Sensor is Complete.
If the status is still Incomplete, drive the vehicle according to the driving pattern again.
HINT:
- Complete indicates that the component is functioning normally.
- Incomplete indicates that the component is malfunctioning.
(h) Enter the following menus: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details / RANGE B1 S1 / Details; then press the Enter button.
(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 CONTROL THE INJECTION VOLUME FOR 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) Warm up the engine.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / AFS B1 S1 or AFS B2 S1 and Engine Speed.
(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) Accelerator pedal released.
Fully depress the accelerator pedal and run the engine at 2,500 rpm.
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.
- 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 terminal to be reconnected, the vehicle must be driven at 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) Read DTCs using the Techstream.
(b) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Result:
B -- END
A -- Continue to next step.
6. REPLACE AIR FUEL RATIO SENSOR
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) Read DTCs using the Techstream.
(b) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Result:
B -- REPLACE ECM
A -- END
9. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) P0031
NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- Continue to next step.
10. INSPECT INTEGRATION RELAY (A/F RELAY) P0031
NG -- REPLACE INTEGRATION RELAY
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM) P0031
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
12. REPLACE AIR FUEL RATIO SENSOR
NEXT -- Continue to next step.
13. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
14. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Read DTCs using the Techstream.
(b) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
Result:
B -- REPAIR OR REPLACE ECM
A -- END
15. REPLACE AIR FUEL RATIO SENSOR
NEXT -- Continue to next step.
16. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
17. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Put the engine in inspection mode Inspection Mode Procedure.
(b) Connect the Techstream to the DLC3.
(c) Turn the Techstream on.
(d) Read DTCs using Techstream.
(e) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
Result:
B -- REPLACE ECM
A -- END