Troubleshooting
DTC P2197 OXYGEN SENSOR SIGNAL STUCK LEAN (BANK 2 SENSOR 1)CIRCUIT DESCRIPTION
HINT: This DTC is recorded when A/F sensor has a malfunction, although the caption is heated oxygen sensor. The air-fuel ratio sensor are the lamination type. Compared to the conventional type, the sensor and heater portions of the lamination type are narrower overall. Because the heat of the heater acts directly on the alumina and zirconia (of the sensor portion) it accelerates the activation of the sensor.
DTC Detecting Condition:
To obtain a high purification rate of the CO, HC and NOx components of the exhaust gas, a three-way catalytic converter is used. For the most efficient use of the three-way catalytic converter, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel ratio.
The A/F sensor has the characteristic that it provides output voltage* being approximately proportional 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.
By the A/F sensor output, the ECM can determine the deviation amount from the stoichiometric air-fuel ratio and control the proper injection time immediately. If the A/F sensor is out of order, ECM is unable to perform the accurate air-fuel ratio control.
The A/F sensor is equipped with a heater which heats the zirconia element. The heater is controlled by the ECM. When the intake air volume is low (the temperature of the exhaust gas is low), the current flows to the heater to heat the sensor for the accurate oxygen concentration detection.
*: The voltage value changes at the inside of the ECM only.
HINT:
- DTCs P2195 and P2196 means malfunction related to bank 1 A/F sensor circuit.
- DTCs P2197 and P2198 means malfunction 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.
- ensor 1 refers to the sensor closest to the engine assembly.
- After confirming DTC P2195, P2196, P2197 and P2198 use the OBD II scan tool or the hand-held tester to confirm voltage output of A/F sensor (AFS B1 S1/AFS B2 S1) from the "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 hand-held tester.
- The ECM controls the voltage of the AFR+, AFL+, AFR- and AFL- terminals of the ECM to the fixed voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the OBD II scan tool or the hand-held tester.
- The OBD II scan tool (excluding hand-held tester) displays the one fifth of the A/F sensor output voltage which is displayed on the hand-held tester.
Wiring Diagram:
CONFIRMATION DRIVING PATTERN
1. Connect the hand-held tester to the DLC3. (*1)
2. Switch the hand-held tester from the normal mode to the check mode. (*1)
3. Start the engine and warm it up with all the accessory switches OFF.(*2)
4. Drive the vehicle at 60 to 120 km/h (38 to 75 mph) and engine speed at 1,400 to 3,200 rpm for 3 to 5 min.(*3)
HINT: If a malfunction exists, the MIL will illuminate during step (*3)
NOTE: If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a hand-held tester, turn the ignition switch OFF after performing steps (*2) and (*3), then perform steps (*2) and (*3) again.
Step 1 - 2:
Step 2 (Continued):
Step 3 - 4:
Step 5:
Step 6 - 11:
Step 12 - 17:
Step 18:
INSPECTION PROCEDURE
HINT:
Hand-held tester only:
Narrowing down the trouble area is possible by performing ACTIVE TEST of the following "A/F CONTROL" (A/F sensor, heated oxygen sensor or other trouble areas can be distinguished).
a. Perform ACTIVE TEST by the hand-held tester (A/F CONTROL).
HINT: "A/F CONTROL" is an ACTIVE TEST which changes the injection volume to -12.5 % or +25 %.
1. Connect the hand-held tester to the DLC3 on the vehicle.
2. Turn the ignition switch ON.
3. Warm up the engine with the engine speed at 2,500 rpm for approx. 90 sec.
4. Select the item "DIAGNOSIS/ENHANCED OBD II/ACTIVE TEST/ A/F CONTROL".
5. Perform "A/F CONTROL" when 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: However, there is a few second delay in the A/F sensor output. And there is about 20 seconds delay in the heated oxygen sensor output.
The following procedure of A/F CONTROL enables the user to check its output (show its graph indication) of A/F sensor and heated oxygen sensor.
For displaying the graph indication, enter "ACTIVE TEST/ A/F CONTROL/USER DATA", then select "AFS B1 S1 and O2S B1 S2" or "AFS B2S1 and O25S B2S2" by pressing "YES" button and push "ENTER" button before pressing "F4" button.
HINT:
- If DTC P2195 or P2196 is displayed, check bank 1 sensor 1 circuit.
- If DTC P2197 or P2198 is displayed, check 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 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.
- Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:
By putting the vehicle's ECM in the check mode, the 1 trip detection logic is possible instead of the 2 trip detection logic and the sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
1. Clear the DTCs.
2. Set the check mode.
3. Perform a simulation.
4. Check the connector and terminal.
5. Handle the connector.