P0031

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER

Description

SYSTEM DESCRIPTION






The ECM performs ON/OFF duty control of the air fuel ratio (A/F) sensor 1 heater corresponding to the engine operating condition to keep the temperature of air fuel ratio (A/F) sensor 1 element at the specified range.

CONSULT-III 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.

1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to "Diagnosis Procedure".

Wiring Diagram

EC-AF1HB1-01:

EC-AF1HB2-01:

Diagnosis Procedure

Step 1-2:

Step 2 (Continued)-6:

Component Inspection

AIR FUEL RATIO (A/F) SENSOR 1 HEATER




Check resistance between terminals 3 and 4.

Resistance: 2.3 - 4.3 ohms [at 25 °C (77 °F)]

Check continuity between terminals 3 and 1, 2, 5, 6, terminals 4 and 1, 2, 5, 6.

Continuity should not exist.

If NG, replace the air fuel ratio (A/F) sensor 1.

CAUTION:
- Discard any air fuel ratio (A/F) 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 air fuel ratio (A/F) sensor, clean exhaust system threads using Heated Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.