P2196

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

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.

DESCRIPTION

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. 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 means malfunctions related to bank 1 A/F sensor circuit.
- DTCs P2197 and P2198 means 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 entering the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / AFS Voltage B1S1 or AFS Voltage B2S1.
- Short-term fuel trim values can also be read using the Techstream.
The ECM regulates the voltage at the A1A+, A2A+, A1A- and A2A- terminals of the ECM at a constant level. Therefore, the A/F sensor voltage output cannot be confirmed without using the 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) for 5 seconds, despite the HO2 sensor voltage output being less than 0.6 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor voltage output is more than 3.8 V (very lean condition) for 5 seconds, despite the HO2 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 high during acceleration, and the sensor becomes low during deceleration with the throttle valve fully closed. The ECM monitors the air-fuel ratio sensor current during fuel-cut and detects an unusual current value.
- If the cumulative time the sensor output is 3.6 mA or more (P2195: high-side stuck) or 1.4 mA or less (P2196: low-side stuck) exceeds more than 3 seconds, the ECM interprets a malfunction in the air-fuel ratio sensor and sets a DTC.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All:





P2195, P2197 (A/F sensor signal stuck lean):





P2196, P2198 (A/F sensor signal stuck rich):





P2195, P2197 (A/F sensor signal (High side)):





P2196, P2198 (A/F sensor signal (Low side)):





TYPICAL MALFUNCTION THRESHOLDS

P2195, P2197 (A/F sensor signal stuck lean):





P2196, P2198 (A/F sensor signal stuck rich):





P2195, P2197 (A/F sensor signal (High side)):





P2196, P2198 (A/F sensor signal (Low side)):





MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.

WIRING DIAGRAM





CONFIRMATION DRIVING PATTERN

This confirmation driving pattern is used in "PERFORM CONFIRMATION DRIVING PATTERN" procedure of the following diagnostic troubleshooting procedure.









1. Connect the Techstream to the DLC3 (Procedure "A").
2. Turn the ignition switch on (Procedure "B").
3. Turn the tester on (Procedure "C").
4. Clear DTCs DTC Check / Clear (Procedure "D").
5. Start the engine, and warm it up until the ECT reaches 75°C (167°F) or higher (Procedure "E").
6. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Idle Fuel Cut (Procedure "F").
7. Drive the vehicle at between 40 mph (64 km/h) or more for at least 10 minutes. (Procedure "G").
8. Change the transmission to 2nd gear (Procedure "H").
9. Drive the vehicle at proper vehicle speed to perform fuel-cut operation (refer to the following HINT) (Procedure "I").

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).

10. Accelerate the vehicle to 30 mph (48 km/h) or more by depressing the accelerator pedal for at least 10 seconds (Procedure "J").
11. Soon after performing procedure "J" above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal, in order to execute fuel-cut control (Procedure "K").
12. Allow the vehicle to decelerate until the vehicle speed declines to less than 6 mph (10 km/h) (Procedure "L").
13. Repeat procedures from "H" through "K" above at least 3 times in one driving cycle (Procedure "M").

HINT: Completion of all A/F sensor monitors is required to change the value in monitor.

CAUTION: Strictly observe of 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 the Techstream.

1. Connect the Techstream to the DLC3.
2. Start the engine and turn the tester on.
3. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
4. On the tester, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F sensor.
5. Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
6. 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 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.





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, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.

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.
- 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 the Techstream to the DLC3.
(b) Turn the ignition switch on.
(c) Turn the tester on.
(d) Enter the following menus: 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 the 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) Enter 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) Enter the following menu: Powertrain / Engine and ECT / Monitor / O2 Sensor / Details / Range B1S1 or Range B2S1.
(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 the 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 2500 rpm for 90 seconds.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / A/F Control System / Snapshot / AFS Voltage B1S1 or AFS Voltage B2S1 and Engine Speed.
(f) Check the A/F sensor voltage 3 times, when the engine is in each of the following conditions:
(1) While idling (check for at least 30 seconds) (Step (1))
(2) At an engine speed of approximately 2500 rpm (without any sudden changes in engine speed) (Step (2))
(3) Raise the engine speed to 4000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed (Step (3)).
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
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 / Pending.
Result:





B -- CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST
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 / Pending.
Result:





B -- REPLACE ECM
A -- Continue to next step.

9. CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST
NO -- CHECK FOR INTERMITTENT PROBLEMS AND PERFORM CONFIRMATION DRIVING PATTERN
YES -- DTC CAUSED BY RUNNING OUT OF FUEL
10. INSPECT AIR FUEL RATIO SENSOR




(a) Disconnect the A12 or A13 A/F sensor connector.
(b) Measure the resistance between the terminals of the A/F sensor connector.

Standard resistance:

Bank 1





Bank 2





(c) Reconnect the A/F sensor connector.

NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- Continue to next step.

11. INSPECT AIR FUEL RATIO SENSOR HEATER RELAY




(a) Remove the A/F sensor heater relay from the engine room R/B.
(b) Check the A/F sensor heater relay resistance.
Standard resistance:





(c) Reinstall the A/F sensor heater relay.

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 A12 or A13 A/F sensor connector.
(b) Turn the ignition switch on.
(c) Measure the voltage between the +B terminal of the A/F sensor connector and body ground.
Standard voltage:





(d) Turn the ignition switch off.
(e) Disconnect the E5 ECM connector.
(f) Measure the resistance between the terminals of A/F sensor connector and ECM connector.
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 leakage.
OK:
No leakage 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 injector injection (whether fuel volume is high or low, and whether injection pattern is poor) Testing and Inspection.

NG -- REPLACE FUEL INJECTOR ASSEMBLY
OK -- Continue to next step.

16. REPLACE AIR FUEL RATIO SENSOR
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) Read DTCs using the Techstream.
(b) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
Result:





B -- REPLACE ECM AND PERFORM CONFIRMATION DRIVING PATTERN
A -- Continue to next step.

19. CONFIRM WHETHER 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
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 the Techstream to the DLC3.
(b) Turn the ignition switch on and turn the tester on.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
(d) Read DTCs.
Result:





B -- REPLACE ECM
A -- END