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DTC/P0325

P0325: Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)

Quick Answer
Moderata GravitàSicuro da guidare (a breve termine)Impianto elettrico

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.

Costo di riparazione stimatoDa €90 a €1600+, varia in base al veicolo

Scansiona la tua auto in circa 60 secondi: scopri se P0325 è davvero presente, quanto è urgente e quanto dovrebbe costare la riparazione.

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Cosa significa P0325?

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.

P0325 è un codice diagnostico di guasto relativo a impianto elettrico, classificato con gravità moderate. Quando la centralina (ECU) del tuo veicolo rileva questa condizione, memorizza P0325 e accende la spia motore.

Quali sono i sintomi di P0325?

Se il tuo veicolo ha attivato P0325, potresti notare uno o più di questi sintomi:

  • Check Engine Light steady on (rarely flashing, unless real knock is also present)
  • Noticeable loss of power under acceleration, especially above 3,000 RPM
  • 5-10% drop in fuel economy on a typical commute
  • Light pinging or metallic rattle under load on low-octane fuel
  • Hesitation or flat spot during part-throttle acceleration
  • Emissions readiness monitor for the misfire/knock system won't complete

Cosa causa P0325?

Ecco le cause più comuni di P0325:

altaFaulty knock sensor (internal open or short in the piezo element)
altaCorroded or damaged connector at the sensor, often from coolant or oil intrusion
mediaDamaged sub-harness (chafing, heat damage, rodent bite)
mediaIncorrect mounting torque or dirty sensor seat degrading signal
bassaPoor engine-to-chassis ground introducing signal noise
bassaFailed knock input circuit inside the ECU/PCM

È sicuro guidare con P0325?

In genere sì, per brevi tragitti. 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.

Come si diagnostica P0325?

Segui questi passaggi per individuare la causa principale di P0325:

  1. Scan the ECU and record freeze frame (RPM, load, coolant temp) at the moment the code set
  2. Visually inspect the knock sensor connector and pigtail for corrosion, oil, coolant or chafing
  3. Measure sensor resistance with a multimeter: piezo types read around 90-100 kΩ or effectively open; check against the factory spec for the specific engine
  4. Backprobe the signal and ground wires at the ECU connector and check continuity and shield integrity to the sensor
  5. With the scan tool live-reading knock voltage or knock counts, tap the block near the sensor with a small wrench to confirm the ECU sees a response
  6. If the sensor and wiring pass, remove the sensor, clean the mounting boss free of paint and rust, and torque to spec (typically 20-25 Nm for Toyota, ~20 Nm for GM LS)
  7. Clear the code and drive under load (moderate acceleration, 2,500-4,000 RPM); if P0325 returns immediately with the sensor and harness confirmed good, suspect the ECU input

Quanto costa riparare P0325?

I costi di riparazione di P0325 variano a seconda della causa principale e del tuo veicolo. Ecco le stime tipiche:

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Knock sensor replacement on an accessible 4-cylinder (side of block) €40–€120 €50–€140 €90–€260 Moderata
Knock sensor replacement under the intake manifold (V6/V8) €60–€180 €300–€700 €360–€880 Professionale
Wiring or connector repair (pin replacement, splice, dielectric reseal) €15–€80 €80–€200 €95–€280 Moderata
Knock sensor sub-harness kit (GM LS valley harness, P/N 12601822 or equivalent) €70–€160 €280–€600 €350–€760 Professionale
ECU/PCM replacement and programming (last resort after circuit verified) €400–€1200 €150–€400 €550–€1600 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

P0325 su veicoli specifici

P0325 si comporta in modo diverso a seconda del tuo veicolo. Seleziona la tua auto qui sotto per cause specifiche del modello, problemi noti e stime dei costi adeguate:

Toyota

P0325 su Toyota Camry

2002-2011

1MZ-FE and 2GR-FE V6 engines are the classic P0325 case. The sensor sits in the valley under the intake manifold. Toyota released updated sensor and sub-harness part numbers (89615-08010 sensor, 82219-33010 harness) to address the pattern failure.

Cosa causa P0325 su una Toyota Camry?

Toyota CamryOriginal sensor internal failure typical past 150,000 km
Toyota CamrySub-harness insulation cracks from heat cycling under the intake
Toyota CamryCorroded connector after intake gasket or coolant work

Costo di riparazione di P0325 per Toyota Camry

Costi stimati per i proprietari di Toyota Camryadeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici Toyota

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Knock sensor replacement on an accessible 4-cylinder (side of block) €56–€168 €70–€196 €126–€364 Moderata
Knock sensor replacement under the intake manifold (V6/V8) €84–€252 €420–€980 €504–€1232 Professionale
Wiring or connector repair (pin replacement, splice, dielectric reseal) €21–€112 €112–€280 €133–€392 Moderata
Knock sensor sub-harness kit (GM LS valley harness, P/N 12601822 or equivalent) €98–€224 €392–€840 €490–€1064 Professionale
ECU/PCM replacement and programming (last resort after circuit verified) €560–€1680 €210–€560 €770–€2240 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Honda

P0325 su Honda Civic

2006-2015

R18A1 (1.8L) and K20/K24 engines. Sensor is bolted to the back of the block below the intake manifold, accessible from underneath. Straightforward DIY with a 12mm socket and long extension.

Cosa causa P0325 su una Honda Civic?

Honda CivicConnector pin corrosion from road spray and engine washing
Honda CivicSensor failure typical past 200,000 km, often with intermittent code first

Costo di riparazione di P0325 per Honda Civic

Costi stimati per i proprietari di Honda Civicadeguato al ribasso rispetto alla media a causa dei prezzi dei ricambi specifici Honda

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Knock sensor replacement on an accessible 4-cylinder (side of block) €32–€96 €40–€112 €72–€208 Moderata
Knock sensor replacement under the intake manifold (V6/V8) €48–€144 €240–€560 €288–€704 Professionale
Wiring or connector repair (pin replacement, splice, dielectric reseal) €12–€64 €64–€160 €76–€224 Moderata
Knock sensor sub-harness kit (GM LS valley harness, P/N 12601822 or equivalent) €56–€128 €224–€480 €280–€608 Professionale
ECU/PCM replacement and programming (last resort after circuit verified) €320–€960 €120–€320 €440–€1280 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Volkswagen

P0325 su Volkswagen Golf

2005-2014

2.0 TFSI (BPY, CCTA) and 1.4 TSI engines. Two knock sensors on the 2.0; P0325 (VAG code 17733) refers to sensor 1 at the front of the block. Often misdiagnosed as an ignition coil issue.

Cosa causa P0325 su una Volkswagen Golf?

Volkswagen GolfSensor mounting bolt corrosion reducing ground contact and signal
Volkswagen GolfHarness chafing where it routes past the timing chain cover
Volkswagen GolfCarbon buildup on intake valves triggering real knock that eventually flags a circuit fault

Costo di riparazione di P0325 per Volkswagen Golf

Costi stimati per i proprietari di Volkswagen Golfadeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici Volkswagen

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Knock sensor replacement on an accessible 4-cylinder (side of block) €44–€132 €55–€154 €99–€286 Moderata
Knock sensor replacement under the intake manifold (V6/V8) €66–€198 €330–€770 €396–€968 Professionale
Wiring or connector repair (pin replacement, splice, dielectric reseal) €17–€88 €88–€220 €105–€308 Moderata
Knock sensor sub-harness kit (GM LS valley harness, P/N 12601822 or equivalent) €77–€176 €308–€660 €385–€836 Professionale
ECU/PCM replacement and programming (last resort after circuit verified) €440–€1320 €165–€440 €605–€1760 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Chevrolet

P0325 su Chevrolet Silverado

1999-2013

GM LS-series V8 (4.8, 5.3, 6.0) with knock sensors mounted in the lifter valley under the intake manifold. Failures from coolant seepage past the sensor O-rings are so common GM sells a full replacement kit (12601822) with new sensors, harness, and grommets.

Cosa causa P0325 su una Chevrolet Silverado?

Chevrolet SilveradoCoolant intrusion from failed valley cover or intake gaskets shorting the sensors
Chevrolet SilveradoSub-harness insulation breakdown from decades of heat exposure
Chevrolet SilveradoOriginal AC Delco sensors typically fail between 160,000 and 200,000 km

Costo di riparazione di P0325 per Chevrolet Silverado

Costi stimati per i proprietari di Chevrolet Silveradoadeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici Chevrolet

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Knock sensor replacement on an accessible 4-cylinder (side of block) €52–€156 €65–€182 €117–€338 Moderata
Knock sensor replacement under the intake manifold (V6/V8) €78–€234 €390–€910 €468–€1144 Professionale
Wiring or connector repair (pin replacement, splice, dielectric reseal) €20–€104 €104–€260 €124–€364 Moderata
Knock sensor sub-harness kit (GM LS valley harness, P/N 12601822 or equivalent) €91–€208 €364–€780 €455–€988 Professionale
ECU/PCM replacement and programming (last resort after circuit verified) €520–€1560 €195–€520 €715–€2080 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

BMW

P0325 su BMW 3 Series

2000-2013

M54, N52 and N54 inline-6 engines. Knock sensors bolt to the underside of the intake manifold on M54/N52. On N54, a P0325 (BMW fault 29CD) often shows up alongside HPFP or coil issues and gets misdiagnosed.

Cosa causa P0325 su una BMW 3 Series?

BMW 3 SeriesLoose sensor mounting bolt after previous intake work, degrading signal coupling
BMW 3 SeriesConnector damage during spark plug or valve cover gasket service
BMW 3 SeriesValve cover or water pump seepage dripping onto the sensor connector

Costo di riparazione di P0325 per BMW 3 Series

Costi stimati per i proprietari di BMW 3 Seriesadeguato al rialzo rispetto alla media a causa dei prezzi dei ricambi specifici BMW

Riparazione Costo dei ricambi Costo della manodopera Stima totale Difficoltà fai-da-te
Knock sensor replacement on an accessible 4-cylinder (side of block) €56–€168 €70–€196 €126–€364 Moderata
Knock sensor replacement under the intake manifold (V6/V8) €84–€252 €420–€980 €504–€1232 Professionale
Wiring or connector repair (pin replacement, splice, dielectric reseal) €21–€112 €112–€280 €133–€392 Moderata
Knock sensor sub-harness kit (GM LS valley harness, P/N 12601822 or equivalent) €98–€224 €392–€840 €490–€1064 Professionale
ECU/PCM replacement and programming (last resort after circuit verified) €560–€1680 €210–€560 €770–€2240 Professionale

Prezzi stimati al March 2026. I costi variano in base alla regione, al veicolo e all'officina.

Questi codici compaiono spesso insieme a P0325 o indicano problemi correlati:

P0326P0327P0328P0330P0332

Domande frequenti su P0325

Will P0325 damage my engine if I keep driving?

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.

Why did P0325 come back after I replaced the knock sensor?

Nine times out of ten it's the harness, connector, or a cheap aftermarket sensor. Denso, Bosch, and NTK OEM units are worth the extra €20-€40, especially on Toyota 1MZ/2GR V6s and GM LS engines where generic sensors often fail within a year.

Can bad fuel cause P0325?

Low-octane fuel causes real knock, which usually sets P0324, P0327 or P0328, not P0325. P0325 is a circuit fault, meaning voltage out of range. If you filled up with cheap fuel and the light came on, scan it before assuming the sensor is bad.

How hard is it to replace the knock sensor myself?

On a 4-cylinder with the sensor on the side of the block (Civic R18, most Mazdas), it's a 30-minute job with a 10mm socket and an extension. On a V6 or V8 with the sensor in the lifter valley (Toyota 2GR, GM LS, BMW N52), plan a full day and budget for new intake manifold gaskets.

Does P0325 fail an MOT or emissions inspection?

Yes. In most EU countries and US states an active MIL is an automatic fail, regardless of the specific code. Readiness monitors also won't set until the code is cleared and a full drive cycle is completed, so don't clear it right before your inspection.

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