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)
DESCRIPTION
DTC Detection Condition (Part 1):
DTC Detection Condition (Part 2):
The air-fuel ratio (A/F) sensor provides output voltage* which is almost 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 carbon monoxides (CO), hydrocarbons (HC) and nitrogen oxides (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 inside the ECM only.
HINT:
- Sensor 1 refers to the sensor closest to the engine assembly.
- After confirming DTC P2195 and P2196, use the intelligent tester to confirm voltage output of A/F sensor (AFS B1 S1) from the "DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY."
- The A/F sensor's output voltage and the short-term fuel trim value can be read using the intelligent tester.
- The ECM controls the voltage of the A1A+, and A1A- terminals of the ECM to a fixed voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the intelligent tester.
- The OBD II scan tool (excluding the intelligent tester) displays the one fifth of the A/F sensor output voltage which is displayed on the intelligent tester.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions (Part 1):
Typical Enabling Conditions (Part 2):
Typical Malfunction Thresholds:
Under the air-fuel ratio feedback control, if the voltage output of the A/F sensor indicates RICH or LEAN for a certain period of time or more, the ECM concludes that there is a fault in the A/F sensor system. The ECM will turn on the MIL and a DTC is set.
If the A/F sensor voltage output is less than 2.8 V (indicates very RICH) 5 seconds, the ECM sets DTC P2196.Also, the A/F sensor voltage output is more than 3.8 V (indicates very LEAN) for 5 seconds, DTC P2195 is set.
Wiring Diagram:
CONFIRMATION DRIVING PATTERN
a. Connect the intelligent tester to the DLC3.
b. Switch the ECM from normal mode to check mode using the intelligent tester.
c. Put the engine in inspection mode.
d. Start the engine and warm it up with all the accessory switches OFF.
e. Deactivate the inspection mode and drive the vehicle at 70 to 120 km/h (44 to 75 mph) for 5 to 10 minutes (the engine must run during monitoring).
HINT: If a malfunction exists, the MIL will be illuminated during step (d).
NOTE:
- If the conditions in this test are not strictly followed, no malfunction will be detected. If you do not have the intelligent tester, turn the power switch OFF after performing steps (d) and (e), then perform steps (d) and (e) again.
- Do not drive the vehicle without deactivating inspection mode, otherwise damaging the transaxle may result.
INSPECTION PROCEDURE
HINT:
- Although each DTC title says "oxygen sensor", these DTCs are related to the A/F sensor.
- Malfunctioning areas can be found by performing the ACTIVE TEST / A/F CONTROL operation. The A/F CONTROL operation can determine if the A/F sensor, heated oxygen sensor or other potential trouble area are malfunctioning or not.
Perform the ACTIVE TEST A/F CONTROL operation.
HINT: The A/F CONTROL operation lowers the injection volume 12.5% or increases the injection volume 25%.
1. Connect the intelligent tester to the DLC3.
2. Turn the power switch ON (IG).
3. Put the engine in inspection mode.
4. Warm up the engine by running the engine at 2,500 rpm, depressing the accelerator pedal more than 60% for approximately 90 seconds.
5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
6. Perform the A/F CONTROL operation with the engine in an idle condition (press the right or left button).
Result:
A/F sensor reacts in accordance with increase and decrease of injection volume:
+25% --> rich output: Less than 3.0 V
-12.5% --> lean output: More than 3.35 V
Heated oxygen sensor reacts in accordance with increase and decrease of injection volume:
+25% --> rich output: More than 0.55 V
-12.5% --> lean output: Less than 0.4 V
NOTE: The A/F sensor output has a few seconds of delay and the heated oxygen sensor output has about 20 seconds of delay at maximum.
The following A/F CONTROL procedure enables the technician to check and graph the voltage output of both A/F sensor and heated oxygen sensor.
To display the graph, enter ACTIVE TEST/ A/F CONTROL/USER DATA, select "AFS B1S1 and O2S B1S2" by pressing the "YES" button followed by the "ENTER" button and then the "F4" button.
HINT:
- Read freeze frame data using the intelligent tester. 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 high A/F sensor voltage could be caused by a RICH air-fuel mixture. Check the conditions that would cause the engine to run with the RICH air-fuel mixture.
- A low A/F sensor voltage could be caused by a LEAN air-fuel mixture. Check the conditions that would cause the engine to run with the LEAN air-fuel mixture.
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