P1256 Possible Causes
- Faulty engine coolant temperature sensor
- Engine coolant temperature sensor harness is open or shorted
- Poor electrical connection in engine coolant temperature sensor circuit
How is code P1256 repaired?
Start by checking the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
- Check Engine Light on (or Service Engine Soon warning light)
P1256 Meaning
The Engine Control Module (ECM) monitors the engine coolant temperature sensor. The ECM sets the OBDII code when the engine coolant temperature sensor does not meet factory specifications.