Possible causes

– Faulty Crankshaft Position (CKP) Sensor
– Crankshaft Position (CKP) Sensor harness is open or shorted
– Crankshaft Position (CKP) Sensor circuit poor electrical connection
– Communication error between the Engine Control Module (ECM) and Transmission Control Module (TCM)

When is the code detected?

The P0728 Codes is triggered when the TCM detected that the engine speed received from the ECM is intermittent.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0728 MAZDA Description

The Engine Control Module (ECM) monitors the engine speed through the Crankshaft Position (CKP) sensor with the engine running, and send signal to the Transmission Control Module (TCM).