DTC 0410

Front Heated Oxygen Sensors (0410: Right Bank) (0414: 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. The "lean" output is sufficiently low. When both the outputs are shifting to the rich 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).


OVERALL FUNCTION CHECK
Use this procedure to check the overall tunction of the front heated oxygen sensor circuit. During this check, a 1st trip DTC might not be confirmed.






Without TOOLS
(1) Start engine and warm it up to normal operating temperature.
(2) Set voltmeter probes between ECM terminal (50) RH, (51) LH (sensor signal) and (25) (engine ground).
(3) Check the following with engine speed held at 2,000 rpm constant under no load.
- The maximum voltage is over 0.8 V at least one time.
- The minimum voltage is below 0.35 V at least one time.






Electrical Diagrams/Left Bank






Circuit Connectors/Left Bank






Electrical Diagrams/Right Bank






Circuit Connectors/Right Bank

1 Of 2:

2 Of 2:

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 tan 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.






Without TOOLS
(1) Start engine and warm it up to normal operating temperature.
(2) Set voltmeter probes between ECM terminal (50) RH, (51) LH (sensor signal) and (25) (ECM ground).
(3) Check the following with engine speed held at 2,000 rpm constant under no load.
- Malfunction indicator lamp goes on more than 5 times within 10 seconds in Diagnostic Test Mode II (FRONT HEATED OXYGEN SENSOR MONITOR).
- The maximum voltage is over 0.6 V at least one time.
- The minimum voltage is below 0.35 V at least one time.
- The voltage never exceeds 1.0 V.