P1150
DTC P1150 A/F SENSOR CIRCUIT RANGE/PERFORMANCE MALFUNCTION (BANK 2 SENSOR 1)CIRCUIT DESCRIPTION
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 voltage, 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 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.
HINT:
- After confirming DTC P1130 and P1150, use the OBD II scan tool or LEXUS hand-held tester to confirm output voltage of A/F sensor (AFS B1 S1/O2S B1 S1) from the CURRENT DATA.
- The A/F sensor's output voltage and the short-term fuel trim value can be read by using the OBD II scan tool or LEXUS 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 LEXUS hand-held tester.
- OBD II scan tool (excluding LEXUS hand-held tester) displays the one fifth of the A/F sensor output voltage which is displayed on the LEXUS hand-held tester.
Wiring Diagram:
CONFIRMATION DRIVING PATTERN
1. Connect the LEXUS hand-held tester to the DLC3.
2. Switch the LEXUS hand-held tester from the normal mode to the check mode.
3. Start the engine and warm it up with all the accessory switches OFF.
4. Drive the vehicle at 60 - 120 km/h (38-75 mph) and engine speed at 1,400 - 3,200 rpm for 3 - 5 minutes.
HINT: If a malfunction exists, the MIL will light up during step (d).
NOTE: If the conditions In this test are not strictly followed, the detection of the malfunction is impossible.
If you do not have a LEXUS hand-held tester, turn the ignition switch OFF after performing steps (c) and (d) once, then perform steps (c) and (d) again.
Steps 1 - 2:
Step 2 (continued) - 4:
Step 4 (continued) - 9:
Step 9 (continued) - 10:
INSPECTION PROCEDURE
HINT:
- If DTC P1130 is displayed, check Bank 1 Sensor 1 circuit.
- If DTC P1150 is displayed, check Bank 2 Sensor 1 circuit.
- Read freeze frame data using LEXUS hand-held tester or OBD II scan tool, as freeze frame data records the engine conditions when the 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
HINT:
LEXUS hand-held tester only:
By putting the vehicle's ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detection logic and the sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
a. Clear the DTC (See step 2).
b. Set the check mode (See step 3).
c. Perform a simulation test.
d. Check the connector and terminal.
e. Handle the connector.