P0135

SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 1 heaters (front) corresponding to the engine speed.

Operation:

Consult-II Reference Value In Data Monitor Mode:

ON BOARD DIAGNOSIS LOGIC
Malfunction is detected when the current amperage in the heated oxygen sensor 1 heater (front) circuit is out of the normal range. (An improper voltage drop signal is sent to ECM through the front heated oxygen sensor heater.)

Possible Cause
- Harness or connectors
[The heated oxygen sensor 1 heater (front) circuit is open or shorted.]
- Heated oxygen sensor 1 heater (front)

DTC Confirmation Procedure

NOTE: If "DTC 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 between 10.5 V and 16 V at idle.

WITH CONSULT-II
1. Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT-II.

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" at the end of the article.

WITH GST
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" at the end of the article.
- When using GST, "DTC Confirmation Procedure" should be performed twice as much as when using CONSULT-II because GST cannot display MODE 7 (1st trip DTC) concerning this diagnosis. Therefore, using CONSULT-II is recommended.