Circuit Open/Short Inspection

Disconnect the PCM connector.
Disconnect the ECT sensor connector.
Inspect the following wiring harnesses for open or short circuit. (Continuity inspection)

Fig 1: Identifying ECT And PCM Sensor Connector Terminals

G05981133

Courtesy of MAZDA MOTORS CORP.

Open circuit

If there is no continuity in the following wiring harnesses, there is an open circuit. Repair or replace the wiring harness.

ECT sensor terminal A and PCM terminal 2AH
ECT sensor terminal B and PCM terminal 2AY

Short circuit

If there is continuity at the following wiring harnesses, there is a short circuit. Repair or replace the wiring harness.

ECT sensor terminal A and body ground
ECT sensor terminal A and power supply