P0325 Ford F-150
Knock Sensor 1 Circuit Malfunction (Bank 1) · Powertrain Code · Medium · Repair: Moderate
What is P0325?
The knock sensor 1 on bank 1 is not functioning properly. The ECM cannot detect engine knock/detonation.
When the Ford F-150 triggers code P0325 (knock sensor 1 circuit malfunction (bank 1)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Ford F-150.
This repair is rated moderate, meaning some experience and specialty tools required.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Ford F-150.
Common Causes on Ford F-150
- Failed knock sensor (bank 1) — heat cycling degrades the sensor over time
- Corroded knock sensor connector or wiring
- Knock sensor not torqued to spec after previous service
- Engine mechanical noise being misinterpreted as knock
Symptoms
- Check engine light
- Reduced engine performance (PCM retards timing as a safety measure)
- Slightly lower fuel economy
- No audible symptom in most cases
Notes for Ford F-150
Knock sensors on Ford V6 and V8 engines are buried under the intake manifold — the part is cheap but labor is significant.