P0161

System Description
The ECM performs ON/OFF control of the heated oxygen sensor 2 heaters (rear) corresponding to the engine speed.

Operation:

Consult-II Reference In Data Monitor Mode:

ECM Terminals And Reference Value:

On Board Diagnosis Logic
Malfunction is detected when the current amperage in the heated oxygen sensor 2 heater (rear) circuit is out of the normal range. [An improper voltage drop signal is sent to ECM through the heated oxygen sensor 2 heater (rear).]

Possible Cause
- Harness or connectors
[The heated oxygen sensor 2 heater (rear) circuit is open or shorted.]
- Heated oxygen sensor 2 heater (rear)

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.
3. Drive vehicle at a speed of more than 70 kph (43 MPH) for 2 consecutive minutes.

4. Stop vehicle and let engine idle for at least 6 seconds.
5. If 1st trip DTC is detected, go to "Diagnostic Procedure" below.

With GST
1. Start engine.
2. Drive vehicle at a speed of more than 70 kph (43 MPH) for 2 consecutive minutes.
3. Stop vehicle and let engine idle for at least 6 seconds.
4. Turn ignition switch "OFF" and wait at least 10 seconds.
5. Start engine.
6. Drive vehicle at a speed of more than 70 kph (43 MPH) for 2 consecutive minutes.
7. Stop vehicle and let engine idle for at least 6 seconds.
8. Select "MODE 3" with GST.
9. If DTC is detected, go to "Diagnostic Procedure" below.
- 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.

Wiring Diagram

RIGHT BANK