Troubleshooting
DTC P2195 A/F Sensor Range/Performance Lean Side (Bank 1 Sensor 1)CIRCUIT DESCRIPTION
DTC Detection Condition:
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three-way catalytic converter is used, but 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 provides output voltage* 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 malfunctioning, ECM is unable to perform 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 temp. of the exhaust gas is low), current flows to the heater to heat the sensor for accurate oxygen concentration detection.
*: The voltage value changes at the inside of the ECM only.
HINT:
- After confirming DTCs P2195, P2196, P2197 or P2198 use the OBD II scan tool or hand-held tester to confirm the voltage output of the A/F sensor (AFS B1 S1/O2S B1 S1) from "CURRENT DATA".
- The A/F sensor's output voltage and the short-term fuel value can be read using the OBD II scan tool or hand-held tester.
- The ECM controls the voltage of AFR/AFL(+) and AFR/AFL(-) terminals of ECM to the fixed voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the OBD II scan tool or hand-held tester.
- 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.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
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.
Example:
If the A/F sensor voltage output is less than 2.8 V (very RICH) for 10 seconds even though voltage output of the heated oxygen sensor output voltage is less than 0.85 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) 10 seconds, DTC P2195 is set.
Wiring Diagram:
Step 1 - 2:
Step 3:
Step 3 (Continued) - 4:
Step 5 - 9:
Step 10 - 14:
Step 15 - 19:
INSPECTION PROCEDURE
HINT:
- If DTC P2195 and P2196 is displayed, check Bank 1 Sensor 1 circuit.
- If DTC P2197 and P2198 is displayed, check Bank 2 Sensor 1 circuit.
- Read freeze frame data using OBD II scan tool or hand-held tester, 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.
CONFIRMATION DRIVING PATTERN
Confirmation Driving Pattern:
1. Connect the hand-held tester to the DLC3.
2. Switch the hand-held tester from normal mode to check mode .
3. Start the engine and warm it up for 2 min. or more with all accessory switches OFF.
4. Drive the vehicle at 60 - 120 km/h (38 - 75 mph) and engine speed at 1,600 - 3,200 rpm for 3 - 5 minutes
HINT: If a malfunction exists, the MIL will light up during step (4).
NOTE: If the conditions in this test are not strictly followed, detection of the malfunction will impossible. If you do not have a hand-held tester, turn the ignition switch OFF after performing steps(3) and (4), then perform steps (3) and (4) again.
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.
a. Clear the DTCs.
b. Set the check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and connector.