Function Explanation (DTC Detection Outline)

If the PCM detects an open circuit in the wiring harness between A/F sensor terminal D and PCM terminal 1AB (COM wiring harness), it stores a DTC. In addition, when there is an open circuit in the wiring harness between A/F sensor terminal D and PCM terminal 1AB (COM wiring harness), the A/F sensor terminal F (B+ terminal) becomes unstable. At this time, the PCM determines an open circuit in the wiring harness (COM wiring harness) between A/F sensor terminal D and PCM terminal 1AB and stores a DTC.
If the A/F sensor does not activate, monitoring cannot occur because the A/F sensor element has an insulation property which keeps it at a specific temperature range or less.

If the PCM detects an open circuit in the wiring harness between A/F sensor terminal D and PCM terminal 1S (COM wiring harness), it stores a DTC. In addition, when there is an open circuit in the wiring harness between A/F sensor terminal D and PCM terminal 1S (COM wiring harness), the A/F sensor terminal F (B+ terminal) becomes unstable. At this time, the PCM determines an open circuit in the wiring harness (COM wiring harness) between A/F sensor terminal D and PCM terminal 1S and stores a DTC.
If the A/F sensor does not activate, monitoring cannot occur because the A/F sensor element has an insulation property which keeps it at a specific temperature range or less.