MAZDA6 (2.3L)
- Resistance Inspection
Remove Engine Coolant Temperature (ECT) sensor. Place ECT sensor in water with thermometer, and heat water gradually. Using DVOM, measure resistance at specified temperatures. See ENGINE COOLANT TEMPERATURE (ECT) SENSOR SPECIFICATIONS table. If ECT sensor is okay, but PID value is out of specification, check for open or short circuit. Go to next step. If resistance reading is not as specified, replace ECT sensor. - Open Circuit Inspection
Check for continuity between following terminals:- ECT sensor harness connector terminal "A" and PCM 30-pin harness connector terminal No. 1M (Light Green/black wire).
- ECT sensor harness connector terminal "B" and PCM 30-pin harness connector terminal No. 2H (Brown wire).
If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
- Short Circuit Inspection
Check for continuity between following:- ECT sensor harness connector terminal "A" (Light Green/Black wire) and power supply.
- ECT sensor harness connector terminal "A" (Light Green/Black wire) and body GND.
- ECT sensor harness connector terminal "B" (Brown wire) and power supply.
If continuity is present, repair short circuit in suspect wire or replace wire harness.