DTC 0901

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




CONSULT REFERENCE VALUE IN DATA MONITOR MODE




ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and (43) (ECCS ground).




ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE DETECTING CONDITION
With Consult
(1) Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT.
(2) Start engine and run it at least 6 seconds at idle speed.

OR

With GST
(1) Start engine and run it at least 6 seconds at idle speed.
(2) Select "MODE 3" with GST.

OR

No Tools
(1) Start engine and run it at least 6 seconds at idle speed.
(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.




DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION
Front Heated Oxygen Sensor Heater




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

Resistance: 2.3 - 4.3 Ohms at 23°C (73°F)

If NG, replace 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.