P0051

DTC P0051 HO2S1 Heater

Description

System Description:

Operation:

The ECM performs ON/OFF control of the heated oxygen sensor 1 heater corresponding to the engine speed and engine coolant temperature. The duty percent varies with engine coolant temperature when engine is started.

Consult-II Reference Value In Data Monitor Mode:

On Board Diagnosis Logic:

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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch "OFF" and wait at least 10 seconds.





3. Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT-II.
4. Start engine and run it for at least 6 seconds at idle speed.
5. If 1st trip DTC is detected, go to "Diagnostic Procedure" below.

WITH GST
1. Start engine and warm it up to normal operating temperature.
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. Turn ignition switch "OFF" and wait at least 10 seconds.
5. Start engine and run it for at least 6 seconds at idle speed.
6. Select "MODE 3" with GST.
7. 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.

EC-O2H1B1-01:

EC-O2H1B2-01:

Wiring Diagram

Diagnostic Procedure Step 1:

Diagnostic Procedure Step 2 - 5:

Diagnostic Procedure Step 6 - 8:

Diagnostic Procedure


Component Inspection

HEATED OXYGEN SENSOR 1 HEATER








1. Check resistance between HO2S1 terminals as follows.
2. If NG, replace heated oxygen sensor 1.

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.
- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.


CONDENSER

1. Turn ignition switch "OFF".
2. Disconnect condenser harness connector.





3. Check resistance between condenser terminals 1 and 2.

Resistance Above 1 MOhm at 25 °C (77 °F)