With CONSULT
Front Heated Oxygen Sensors (P0131: Right Bank) (P0151: Left Bank)
COMPONENT DESCRIPTION
The front heated oxygen sensor is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The front heated oxygen sensor has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1 V in richer conditions to 0 V in leaner conditions. The front heated oxygen sensor signal is sent to the ECM. The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1 V to 0 V.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Specification data are reference values.
ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values, and are measured between each terminal and (25) (ECCS ground).
ON BOARD DIAGNOSIS LOGIC
To judge the malfunction, the output from the front heated oxygen sensor is monitored to determine whether the "rich" output is sufficiently high and whether the "lean" output is sufficiently low. When both the outputs are shifting to the lean side, the malfunction will be detected.
DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
CAUTION: Always drive vehicle at a safe speed.
NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has just been completed, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.
TESTING CONDITION:
Always perform at a temperature of more than -10°C (14°F).
Before performing following procedure, confirm that battery voltage is more than 11 V at idle.
Never raise engine speed above 3,600 rpm (A/T), 4,000 rpm (M/T) during the "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE". If the engine speed limit is exceeded, retry the procedure from step 2).
With CONSULT
(1) Start engine and warm it up to normal operating temperature.
(2) Stop engine and wait at least 5 seconds.
(3) Turn ignition switch "ON" and select "FR O2 SEN-B1 (-B2) P0131 (P0151)" of "FRONT O2 SENSOR" in "DTC WORK SUPPORT" mode with CONSULT.
(4) Touch "START".
(5) Start engine.
(6) When the following conditions are met, "TESTING" will be displayed on the CONSULT screen. Maintain the conditions continuously until "TESTING" changes to "COMPLETED". (It will take approximately 50 seconds.)
CKPS-RPM (POS): 1,650 - 2,400 rpm (A/T models)
2,000 - 2,600 rpm (M/T models)
Vehicle speed: 78 - 100 km/h (48 - 62 MPH)
B/FUEL SCHDL: 2.4 - 4.5 ms
Selector lever: Suitable position
If "TESTING" is not displayed after 5 minutes, retry from step 2).
(7) Make sure that "OK" is displayed after touching "SELF-DIAG RESULTS". If "NG" is displayed, refer to "DIAGNOSTIC PROCEDURE".
Electrical Diagrams/Left Bank
Circuit Connectors/Left Bank
Electrical Diagrams/Right Bank
Circuit Connectors/Right Bank
DIAGNOSTIC PROCEDURE
COMPONENT INSPECTION
Front heated oxygen sensor heater
Check resistance between terminals (3) and (1).
Resistance: 2.3 - 4.3 Ohms at 25°C (77°F)
Check continuity between terminals (2) and (1), (3) and (2).
Continuity should not exist.
If NG, replace the front heated oxygen sensor.
CAUTION: Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
With CONSULT
(1) Start engine and warm it up to normal operating temperature.
(2) Select "MANU TRIG" and "HI SPEED" in "DATA MONITOR" mode with CONSULT, and select "FR O2 SEN-B1 (-B2)" and "FR O2 MNTR-B1 (-B2)".
(3) Hold engine speed at 2,000 rpm under no load during the following steps.
(4) Touch "RECORD" on CONSULT screen.
(5) Check the following.
* "FR O2 MNTR-B1 (-B2)" in "DATA MONITOR" mode changes from "RICH" to "LEAN" to "RICH" 5 times in 10 seconds.
5 times (cycles) are counted as shown below:
Cycle | 1 | 2 | 3 | 4 | 5 |
FR O2 MNTR-B1 R-L-R-L-R-L-R-L-R-L-R
R = "FR O2 MNTR-B1 (-B2)", "RICH"
L = "FR O2 MNTR-B1 (-B2)", "LEAN"
* "FR O2 SEN-B1 (-B2)" voltage goes above 0.6 V at least once.
* "FR O2 SEN-B1 (-B2)" voltage goes below 0.35 V at least once.
* "FR O2 SEN-B1 (-B2)" voltage never exceeds 1.0 V.