P2196
DTC P2195 Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1DTC 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
DTC Detection Condition:
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 air-fuel ratio detection. In addition, the sensor and heater portions are the narrow type. The heat generated by the heater is conducted to the solid electrolyte through 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 into 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 No. 1 cylinder.
- Bank 2 refers to the bank that includes No. 2 cylinder.
- When either of these DTCs is set, check the A/F sensor output voltage by entering the following menus:
- Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / DATA LIST / A/F CONTROL SYS / AFS B1 S1 or AFS B2 S1.
- Techstream - Select: Powertrain / Engine and ECT / Data List / A/F Control System / AFS B1 S1 or AFS B2 S1.
- Short-term fuel trim values can also be read using the intelligent tester or Techstream.
- The ECM regulates the voltages at the A1A+ and A1A- or A2A+ and A2A- terminals of the ECM to a constant level. Therefore, the A/F sensor output voltage cannot be confirmed without using the intelligent tester or Techstream.
- If the A/F sensor is malfunctioning, the ECM sets the DTC P2195, P2196, P2197 or P2198.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds (Part 1):
Typical Malfunction Thresholds (Part 2):
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 less than 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 1.4 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 orP2198 (low-side stuck).
MONITOR RESULT
Refer to CHECKING MONITOR STATUS Checking Monitor Status
Wiring Diagram:
CONFIRMATION DRIVING PATTERN
CAUTION: Strictly observe posted speed limits, traffic laws, and road conditions when performing these drive patterns.
This confirmation driving pattern is used in the "PERFORM CONFIRMATION DRIVING PATTERN" procedure of the following diagnostic troubleshooting procedure.
a. Connect the intelligent tester or Techstream to the DLC3.
b. Turn the ignition switch ON.
c. Turn the tester ON.
d. Clear DTCs.
e. Start the engine, and warm it up until the ECT reaches 75 °C (167 °F) or higher.
f. Enter the following menus:
- Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / FC IDL.
- Techstream - Select: Powertrain / Engine and ECT / Data List / All Data / Idle Fuel Cut.
g. Drive the vehicle at between 60 km/h (38 mph) and 120 km/h (75 mph) for at least 10 minutes.
h. Change the transmission to 2nd gear.Monitor Drive Pattern: ECT: 75 °C (167 °F) or more
i. Drive the vehicle at the proper vehicle speed to perform fuel-cut operation.
HINT: Fuel-cut is performed when the following conditions are met:
- Accelerator pedal fully released.
- Engine speed is 2500 rpm or more (fuel injection returns at 1000 rpm).
j. Accelerate the vehicle to 64 km/h (40 mph) 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 10 km/h (6 MPH).
m. Repeat steps h. through k. at least 3 times in one driving cycle.
HINT:
- Intelligent tester: Completion of all A/F sensor monitors is required to change the value in TEST RESULT.
- Techstream: Completion of all O2S (A/F) Monitor id required to change the value in Data List.
Step 1-2:
Step 2(Continued)-3:
Step 3(Continued):
Step 3(Continued)-8:
Step 8(Continued)-10:
Step 11:
Step 11(Continued)-14:
Step 14(Continued):
INSPECTION PROCEDURE
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.
- DTC P2A00 may be set when the air-fuel ratio is stuck rich or lean.
- Read freeze frame data using the intelligent tester or Techstream. Freeze frame data records 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.
HINT: Malfunctioning areas can be identified by performing the A/F CONTROL (Control the Injection Volume for A/F Sensor) function provided in the Active Test. The A/F CONTROL (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 A/F CONTROL (Control the Injection Volume for A/ F Sensor) operation using the tester.
a. Connect the intelligent tester or 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. On the tester, enter the following menus:
- Intelligent tester -Select: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
- Techstream - Select: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
e. Perform the A/F CONTROL (Control the Injection Volume for A/F Sensor) operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
f. 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 tester.
HINT:
- The A/F CONTROL (Control the Injection Volume for A/F Sensor) operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- The sensors react in accordance with increases and decreases in the fuel injection volume.
NOTE: The A/F sensor has an output delay of a few seconds and the HO2 sensor (for sensor 2) output has a maximum output delay of approximately 20 seconds. following the A/F CONTROL (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 menus on the tester:
- Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2; then press the YES button and the ENTER button followed by the F4 button.
- Techstream - Select: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/ F Sensor / A/F Control System / AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2.