What does code P1256 mean?

Q: What does code P1256 mean?

Engine Coolant Temperature Circuit Open/Short To B+. P1256 on Volkswagen vehicles means the engine control module (ECM) has detected an open circuit or a short to battery voltage on the engine coolant temperature (ECT) sensor signal circuit. The ECM expects a voltage between roughly 0.5 and 4.5 volts as the engine warms, but it sees either a near-zero or a near-battery voltage that does not change with temperature.

DTC codes / Volkswagen codes / P1256

P1256 · VolkswagenEngine Coolant Temperature Circuit Open/Short To B+

P1256 on Volkswagen vehicles means the engine control module (ECM) has detected an open circuit or a short to battery voltage on the engine coolant temperature (ECT) sensor signal circuit. The ECM expects a voltage between roughly 0.5 and 4.5 volts as the engine warms, but it sees either a near-zero or a near-battery voltage that does not change with temperature.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.