DTC 0901

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

OPERATION
Engine speed rpm / Front heated oxygen sensor heaters
Above 3.600 (A/T models) or 4,000 (M/T models) / OFF
Below 3,600 (A/T models) or 4,000 (M/T models) / ON




CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.




ECM TERMINALS AND REFERENCE VALUE
Remarks: Specification data are reference values, and are measured between each terminal and (25) (ECCS ground) with a voltmeter.




ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
With Consult




(1) Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT.
(2) Start engine and run it at least 5 seconds at idle speed.

OR

With GST
(1) Start engine and run it at least 5 seconds at idle speed.
(2) Turn ignition switch "OFF" and wait at least 5 seconds.
(3) Start engine and run it for at least 5 seconds at idle speed.
(4) Select "MODE 3" with GST.

OR

No Tools
(1) Start engine and run it at least 5 seconds in idle condition.
(2) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
(3) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
- 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.

EC-FO2H-R-01 Front Heated Oxygen Sensor Heater (Right Bank) (DTC: P0135):

WIRING DIAGRAM




DIAGNOSTIC PROCEDURE

COMP0NENT 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.