P0031

DTC P0031 / P0032

DTC Detecting Condition and Trouble Area






Wiring Diagram










DTC Confirmation Procedure

1) Turn ignition switch to ON position for 10 sec.

DTC Troubleshooting

1.
Was "Engine and Emission Control System Check" performed?
YES -
Go to Step 2.
NO -
Go to Engine and Emission Control System Check Engine and Emission Control System Check.

2. A/F sensor heater power supply circuit check

Turn OFF ignition switch and disconnect connector from A/F sensor.
Check for proper terminal connection to A/F sensor.
If connections are OK, turn ignition switch to ON position.
Check that A/F sensor heater power supply circuit (A1) is battery voltage.

Is it in good condition?
YES -
Go to Step 3.
NO -
Repair or replace defective parts or wire harness.

3. A/F sensor heater drive circuit check

Turn OFF ignition switch and disconnect connectors from ECM.
Check for proper terminal connection to ECM connectors.
If connections are OK, check that A/F sensor heater drive circuit (A2) is as follows.
- Wiring harness resistance of A/F sensor heater drive circuit is less than 3 ohms.
- Insulation resistance between A/F sensor heater drive circuit and vehicle body ground is infinity.
- Insulation resistance of wire harness is infinity between A/F sensor heater drive circuit terminal and each terminal at A/F sensor connector.
- Circuit voltage of A/F sensor heater drive circuit is 0 - 1 V with ignition switch in ON position.

Is it in good condition?
YES -
Go to Step 4.
NO -
Repair or replace defective wire harness.

4. A/F sensor check

Check A/F sensor heater. A/F (Air Fuel Ratio) Sensor On-Vehicle Inspection

Is it in good condition?
YES -
Substitute a known-good ECM and recheck.
NO -
Replace A/F sensor.