Knock sensor reading above expected range.
P0328 — also written PO328, P 0328, 0328 — is the OBD-II code for knock sensor 1 high input. Same code, same fix: this page covers every spelling of it.
P0328 means the ECU is getting a voltage signal from the knock sensor that's way too high, usually common on high-mileage Japanese petrols and Vauxhalls where the wiring has gone brittle.
P0328 is a sensors fault code, typically costing £90–£350 to put right in a UK garage.
What P0328 actually feels like to drive
- The car feels 'flat' or sluggish, like the turbo isn't waking up.
- Worse fuel economy because the ECU is retarding the timing to stay safe.
- A distinct 'pinking' or metallic rattling sound when pulling away in a high gear.
- The EML (Engine Management Light) stays on solid, sometimes flickering under load.
- Engine might hesitate or 'stutter' when you plant your foot to overtake on the A9.
What causes P0328?
- Wiring fault
- Damaged sensor
- Loose block bolt
UK vehicles that throw P0328 most often
- Vauxhall Corsa D/E 1.2 & 1.4 VVT (A12XER/A14XER) 2010-2018
- Subaru Impreza & Forester 2.0 EJ20 (Very common sensor failure)
- Honda Civic 1.8 i-VTEC (R18A) 2006-2012
- Nissan Qashqai 1.6 & 2.0 (HR16DE/MR20DE) 2007-2013
- Mazda 3 1.6 Z6 Engine 2004-2009
- Toyota Yaris 1.33 VVT-i (1NR-FE) 2009-2015
How P0328 is fixed
- Replace sensor
- Repair wiring
The P0328 misdiagnosis that wastes money
I’ve lost count of how many times I’ve seen brand-new knock sensors thrown at a car, only for the P0328 to pop back up ten minutes later. Usually, it's not the sensor itself—it’s the wiring harness being chewed by a rodent or, more commonly on the Corsas, the connector pins getting corroded by road salt. Another one that trips folk up is a loose mounting bolt. If that sensor isn't torqued exactly to spec (usually 20Nm), it rattles about, reads 'High Input,' and the ECU panics.
What a UK garage should charge for P0328
For a basic diagnostic plug-in, expect to pay £50 to £80 at an independent. A quality Bosch or Denso sensor will run you between £40 and £90—don't buy the £15 eBay specials, they never work. Labour is the variable; on a Corsa it's a 30-minute job, but on a Subaru where it's tucked under the intake, you're looking at 2 hours. Total bill usually lands between £120 and £220. If you go to a main dealer, expect that to climb north of £350 once they add their 'environmental' and 'sundry' charges.
P0328 repair cost in the UK
Most P0328 repairs land between £90–£350 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0328
If your garage says you need a new sensor, ask them if they’ve checked the 'knock sensor adaptation' or performed a software update first. On some Vauxhalls and Kias, a simple ECU flash fixes a sensitivity glitch that causes this code. Also, insist they use a torque wrench to fit the new one. If they just zip it up with a rattle gun, it’ll be over-sensitive or crack the ceramic element, and you’ll be back a week later with the same light on. A proper tech will test the wiring resistance from the sensor plug back to the ECU before spending your money on parts.
Can you drive with P0328?
Yes.
Urgency: medium.