Code 0901

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




OPERATION




DIAGNOSTIC CHART




DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE
CONSULT
1) Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT.
2) Start engine and run it for at least 5 seconds at idle speed.

OR

GST
1) Start engine and run it for at least 5 seconds at idle speed.
2) Select "MODE 3" with GST.

OR

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

COMPONENT INSPECTION
Front heated oxygen sensor heater




Check resistance between terminals (3) and (1).

Resistance: 2.3 - 4.3ohms 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.




WIRING DIAGRAM