P0325 means the ECU sees an out-of-range voltage on the bank 1 knock sensor circuit. Without valid knock data the ECU defaults to conservative ignition timing, so you lose power and fuel economy.
Scan your own car in about 60 seconds: see whether P0325 is really what it has, how urgent it is, and what the fix should cost. Free on iPhone and Android, on any ELM327 adapter.
Get Skanyx freeP0325 means the ECU sees an out-of-range voltage on the bank 1 knock sensor circuit. Without valid knock data the ECU defaults to conservative ignition timing, so you lose power and fuel economy.
P0325 is a electrical-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0325 and illuminates the check engine light.
If your vehicle has triggered P0325, you may notice one or more of these symptoms:
Here are the most common causes of P0325:
Generally yes, for short-term driving. You can drive short distances, but the ECU pulls timing as a protection measure. Expect reduced power and worse fuel economy. Avoid heavy throttle and low-octane fuel until it's fixed.
Follow these steps to pinpoint the root cause of P0325:
Repair costs for P0325 vary depending on the root cause and your vehicle. Here are typical estimates:
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
P0325 behaves differently depending on your vehicle. Select your car below for model-specific causes and known issues:
R18A1 (1.8L) and K20/K24 engines. The sensor bolts to the back of the block below the intake manifold and is reached from underneath with a long extension, which makes it a straightforward DIY job.
These codes are often seen alongside P0325 or indicate related issues:
Not on its own. With no valid knock signal the ECU pulls timing as a safeguard, so detonation is unlikely on decent fuel. The risk is that real knock could occur without being detected. Fix it within a few weeks, not months, and stay on 95 RON or higher in the meantime.
A repeat P0325 usually points at the wiring rather than the sensor itself. Check the harness for chafing where it runs under the intake, and check the connector for corrosion or spread pins, before buying a second sensor. If the sensor really is at fault, match the original specification and check its resistance against the figure for your engine, because a sensor that reads out of range will set the code again.
Low-octane fuel causes real knock, which the ECU normally handles by retarding the ignition timing; some engines log it as P0324 or a manufacturer-specific knock control code. It does not set P0325, which is a circuit fault, meaning the sensor signal is electrically out of range. If you filled up with low-octane fuel and the light came on, scan it before assuming the sensor is bad.
On many four-cylinders the sensor bolts to the block where it can be reached from underneath or through a gap below the intake (the Civic R18, for example, has it on the back of the block below the intake manifold), which is usually a job of an hour or two. On a V6 or V8 with the sensors in the valley under the intake manifold (Toyota 2GR, GM LS), and on BMW inline-sixes such as the N52, where they sit on the block under the intake manifold, the manifold has to come off, so plan a full day and budget for new intake manifold gaskets.
Badly. Inspection rules differ by country and by US state, so nobody can promise you a single outcome, but an active MIL with a stored knock sensor code is the kind of defect testers reject. Clearing the code also resets the readiness monitors, which then need a full drive cycle to set again, so clearing it right before your inspection does not help.
A 15 euro Bluetooth adapter and a free phone app read the exact fault code a shop charges 30 to 100 euros to pull. Here is how to do it yourself in 5 minutes.
A flashing check engine light means the engine is misfiring right now. Pull over and read the code: the fix is usually $80 to $400, the delay costs $1,500 up.
An unfamiliar symbol just lit up and you need to know whether to stop. Read the colour first, then find your symbol in the table: every one carries its verdict.
Your car logged P0325. Skanyx reads it on any standard Bluetooth OBD2 adapter, tells you whether it is safe to keep driving, and shows the €90-€1600 repair range so you know the number before a shop quotes you. Free on iPhone and Android, and you do not need to be a mechanic to read it.
Get Skanyx freeGet the newsletter
New fault-code guides, real repair-cost data and seasonal car-care tips. No spam, unsubscribe anytime.
We only email about car diagnostics content. Privacy Policy