P0327: Knock/Combustion Vibration Sensor A Circuit Low
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - power will be down because the computer pulls timing as a precaution.
Symptoms
- Sluggish acceleration
- Slight loss of fuel economy
- Check engine light with no dramatic symptom
Likely causes, most common first
- Knock sensor signal shorted to ground
- Failed sensor
- Harness damage under the intake manifold
- Water intrusion into the connector
Read P0327 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0327 is a low-voltage fault on the knock sensor circuit. Without a trustworthy knock signal the computer cannot safely run its normal ignition advance, so it retards timing across the board - the car still drives, just noticeably flatter, and uses more fuel doing it.
On many V6 and V8 engines the knock sensors live in the valley beneath the intake manifold, where the manifold must come off to reach them and where old harnesses become brittle. Because that labour dominates the bill, replacing both sensors and the connecting harness at the same time is usually the sensible choice.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P0327
“The contact owns a 2020 Ford F-150. The contact stated that the message "Check the engine" was displayed on the mobile App. The contact stated upon starting the vehicle, the check engine warning light was illuminated. The vehicle was taken to the dealer where diagnostic trouble code: P0327 was retrieved. The dealer determined that the engine knock sensor A, three unknown gaskets, and unknown parts needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the vehicle was not covered under warranty and that the VIN was not included in a recall. The failure mileage was approximately 48,000.”2020 Ford F-150 · Dec 2024 · 48,000 mi
“Service Engine Soon light came on while driving. Code P0327 - Knock Sensor 1, Circuit Low Input (Bank 1) shown on code reader. Took vehicle to local service station and had both knock sensors and wiring harness replaced. Mechanic said that the rear knock sensor was corroded due to water getting to the sensor. Drove vehicle for about 2 weeks and service engine light came back on. Took vehicle back to service station where knock sensors were replaced again. Mechanic again stated that the rear sensor was corroded due to water getting to the sensor. Drove vehicle for about 1 week and the Service Engine light has come back on for the third time with the same P0327 code showing.”2006 Chevrolet Silverado 1500 · May 2023
“I bought my 2010 GMC Terrain SLE at 160,000. It had a rough start up but the dealer said it was because it was an older car and been sitting for a while. The rough start up never stopped even after replacing the catalytic converter because of code P0420. The mechanic informed of this specific vehicle oil composition so I was consistently checking the oil. A month after the NEW catalytic converter was installed. I stalled out on the interstate with traffic going 65 mph minimum, the wheel locked and I was almost rear ended. I take the vehicle to an automotive shop and I need a new timing chain with numerous new codes. P0325 P0326 P0327 P0016 P0017 P0014.”2010 GMC Terrain · Nov 2021
Cars that report P0327 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P0327?
Yes - power will be down because the computer pulls timing as a precaution.
How much does it cost to fix P0327?
Typical US repair costs range from $60 for the simplest fix (knock sensor) to $600 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P0327. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.