System: Powertrain (P-Code)
SAE Standard (Generic)
Family: Knock Sensor Circuit
Code P0325: Knock/Combustion Vibration Sensor A Circuit
Diagnostic & Technical Explanation
Code P0325 (Knock/Combustion Vibration Sensor A Circuit) sets when the ECM detects an open circuit, out-of-range voltage, or a total loss of signal from a knock (combustion vibration) sensor used to retard timing and protect the engine from detonation, or when the overall knock control system itself reports an internal error. Physical causes are a failed piezoelectric sensor element, an improperly torqued sensor (knock sensors are torque-sensitive and read incorrectly if over- or under-tightened), or chafed/corroded wiring between the sensor and the ECM.
First-listed procedure
Rank #1
Inspect and reseat the knock sensor connector
Easy DIY
This is the first procedure in the authored
consideration order, not a measured cause likelihood. Execute it only when its prerequisites
and diagnostic findings support it. Its cost and labor estimates (where known), the step-by-step procedure and the
remaining 3 procedure(s) are in the licensed dataset. Ordering context.
Full family: Knock Sensor Circuit
What this page does not show
This page publishes the fault mechanism and the code index. The licensed dataset adds, for
every one of the 15,886 codes, the full authored repair set (56,729 procedures in total)
with the fields deliberately withheld here:
- Procedures 2..n after the first-listed procedure
- Aftermarket parts cost ranges in USD (
est_parts_cost_min/max_usd)
- Professional labor-hour estimates (
est_labor_hours)
- Step-by-step diagnostic and repair instructions
- Replacement-part mappings and catalog lookups
- 6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)