P0031

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

Description




SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating condition to keep the temperature of 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 perform the following before conducting the next step.

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.

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 "Diagnostic Procedure" below.

EC-AF1HB1-01:

EC-AF1HB2-01:

Wiring Diagram

Step 1-2:

Step 2 (Continued)-7:

Diagnostic Procedure

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 A/F sensor 1.

CAUTION:
- Discard any 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 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.