Possible Causes
WARNING: This page is about a different car, the 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
Possible causes are:
- Connector or terminal malfunction
- ECT sensor malfunction
- PCM malfunction
- Short between ECT signal circuit (Light Green/Black wire) and ECT ground circuit (Brown wire) in wire harness
- Short to ground circuit between ECT sensor harness connector terminal "A" and PCM 30-pin harness connector terminal "1M" (Light Green/Black wire)