FR O2 SEN HTR-B1

SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the front heated oxygen sensor heaters corresponding to the engine speed.




OPERATION




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) (ECM ground).




ON BOARD DIAGNOSIS LOGIC




DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 10 seconds before conducting the next test.

TESTING CONDITION: Before performing the following procedure, confirm that battery voltage is more than 10.5 V at idle.

With Consult
1. Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT.
2. Start engine and run it for at least 6 seconds at idle speed.
3. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

With Generic Scan Tools
1. Start engine and run it for at least 6 seconds at idle speed.
2. Turn ignition switch "OFF" and wait at least 10 seconds
3. Start engine and run it for at least 6 seconds at idle speed.
4. Select "MODE 3" with GST.
5. If DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

Without Scan Tools
1. Start engine and run it for at least 6 seconds in idle condition.
2. Turn ignition switch "OFF", wait at least 10 seconds and then turn "ON".
3. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".
- When using GST, "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" should be performed twice as much as when using CONSULT or ECM (Diagnostic Test Mode II) because GST cannot display MODE 7 (1st trip DTC) concerning this diagnosis. Therefore, using CONSULT or ECM (Diagnostic Test Mode II) is recommended.







WIRING DIAGRAM




DIAGNOSTIC PROCEDURE




COMPONENT INSPECTION
Check resistance between terminals (3) and (1).
Resistance: 2.3 - 4.3 Ohm 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.