P2196

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)

HINT: Although the title (DTC description) says "oxygen sensor", this DTC is related to the "A/F sensor".

DESCRIPTION

DTC Detection Condition:

The Air-Fuel ratio (A/F) sensor provides output voltage* approximately equal to the existing air-fuel ratio. The A/F sensor output voltage is used to provide feedback for the ECM to control the air-fuel ratio. With the A/F sensor output, the ECM can determine deviation from the stoichiometric air-fuel ratio and control proper injection time. If the A/F sensor is malfunctioning, the ECM is unable to accurately control the air-fuel ratio.
The A/F sensor is equipped with a heater which heats the zirconia element. The heater is also controlled by the ECM. When the intake air volume is low (the temperature of the exhaust gas is low), current flows to the heater to heat the sensor to facilitate detection of accurate oxygen concentration. The A/F sensor is a planar type. Compared to a conventional type, the sensor and heater portions are narrower. Because the heat of the heater is conducted through the alumina to zirconia (of the sensor portion), sensor activation is accelerated.
To obtain a high purification rate of the CO, HC and NOx components of the exhaust gas, a three-way catalytic converter is used. The converter is most efficient when the air-fuel ratio is maintained near the stoichiometric air-fuel ratio.

*: The voltage value changes on the inside of the ECM only.

HINT:
- DTCs P2195 and P2196 indicate a malfunction related to bank 1 of the A/F sensor circuit.
- DTCs P2197 and P2198 indicate a malfunction related to bank 2 of the A/F sensor circuit.
- Bank 1 is the bank that includes cylinder No. 1.
- Bank 2 is the bank that includes cylinder No. 2.
- Sensor 1 is the sensor closest to the engine assembly.
- After confirming DTCs P2195, P2196, P2197 or P2198, use the intelligent tester or the OBD II scan tool to confirm A/F sensor output voltage (AFS B1S1 / AFS B2S1. from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL).
- The A/F sensor's output voltage and the short-term fuel trim value can be read using the OBD II scan tool or the intelligent tester.
- The ECM controls the voltages of the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a fixed voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the OBD II scan tool or the intelligent tester.
- The OBD II scan tool (excluding intelligent tester) displays one fifth of the A/F sensor output voltage which is displayed on the intelligent tester.

MONITOR DESCRIPTION

A/F Sensor Current Monitor:

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Sensor voltage detection monitor
Under the air-fuel ratio feedback control, if the voltage output of the A/F sensor indicates RICH or LEAN for more than a certain period of time, the ECM concludes that there is a fault in the A/F sensor system. The ECM will turn on the MIL and a DTC will be set.

Example:
If the A/F sensor voltage output is less than 2.8 V (very RICH) for 10 seconds even though the heated oxygen sensor output voltage is less than 0.6 V, the ECM sets DTC P2196 or DTC P2198. If the heated oxygen sensor output voltage is 0.15 V or more but the A/F sensor voltage output is more than 3.8 V (very LEAN) for 10 seconds, DTC P2195 or DTC 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 DTC P2197 (high-side stuck). If the A/F sensor output is less than 1.57 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 or DTC P2198 (low-side stuck).

Wiring Diagram:

CONFIRMATION DRIVING PATTERN

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

Monitor Drive Pattern:

Driving Pattern Detail For (h) Through (k):

a. Connect the intelligent tester 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 degree C (167 degree F) or higher.
f. On the intelligent tester, select the following menu items to check the fuel-cut status: DIAGNOSIS / ENHANCED OBD II / DATA LIST / USER DATA / FC IDLE.
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.

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.

HINT:
Intelligent tester only:
Malfunctioning areas can be identified by performing the A/F CONTROL function provided in the ACTIVE TEST. The A/F CONTROL 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 operation using an intelligent tester.
1. Connect the intelligent tester to the DLC3.
2. Start the engine and turn the tester ON.
3. Warm up the engine at engine speed of 2,500 rpm for approximately 90 seconds.
4. On the tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
5. Perform the A/F CONTROL 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 B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2. displayed on the tester.

Standard:

HINT:
- The A/F CONTROL 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 A/F CONTROL 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: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2, and press the YES button and then the ENTER button followed by the F4 button.

Step 1:

Step 1(contd.)-2:

Step 2(contd.):

Step 3-5:

Step 5(contd.)-7:

Step 8-12:

Step 13-17:

Step 18:

INSPECTION PROCEDURE

HINT:
- If DTC P2195 or P2196 is displayed, check the bank 1 sensor 1 circuit.
- If DTC P2197 or P2198 is displayed, check the bank 2 sensor 1 circuit.
- 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 with a RICH air-fuel mixture.
- 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 with a LEAN air-fuel mixture.
- Read freeze frame data using the intelligent tester or OBD II scan tool. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.