P0329 OBD-II Trouble Code: Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor)

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0329 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0329 code

P0329 is a diagnostic trouble code (DTC) for "Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor)". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0329 DIAGNOSTIC Get a fair and transparent estimate upfront

Check Engine Light

P0329 code definition?

Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor)

What the P0329 code means

A knock sensor is used to optimize engine performance. It also helps protect the engine against potentially dangerous and power robbing engine knock. Trouble code P0329 indicates that the knock sensor detects an abnormal amount of pinging or vibration coming from the engine. The knock sensor will produce a voltage when there is excess knock, spark knock, vibration or engine pinging present. The knock sensor was implemented to help alert the driver of any potential internal engine issues as well as to help monitor the air-fuel ratio (AFR). The voltage signal sent by the knock sensor will tell the Engine Control Module (ECM) if a “knock” is present. If a such knock is present, the ECM will then adjust the air-fuel ratio by the advancement or retard of the timing.

The knock sensor is a type of alarm for the engine. Just as the anti-theft alarm will engage if the vehicle body experiences too much vibration, a knock sensor also becomes engaged through a similar fashion.

Knock sensors were designed to act as a sort of a stress signal for the engine. The internals of the knock sensor are piezoelectric, meaning that it consists of crystals that will generate electricity if it undergoes mechanical stress; the knock sensor is a type of transducer which converts mechanical energy into electricity.

Under normal conditions, a knock sensor will only produce less than one volt, though if a knock sensor experiences too much vibration, it will produce anywhere from 1.0 - 5.0 volts. When the knock sensor’s voltage output is beyond the range that the Engine Control Module expects as “normal”, a code P0329 may set.

What causes the P0329 code?

  • Internal engine mechanical faults such as damaged valves or worn crank bearings
  • Faulty knock sensor
  • Frayed, damaged or contaminated knock sensor wiring
  • Loose knock sensor
  • Knock sensor short to voltage or ground
  • Faulty Engine Control Module
  • Improper or contaminated fuel
  • Low fuel pressure
  • Corroded connections

What are the symptoms of the P0329 code?

  • Lack of power
  • Hesitation when accelerating
  • Knocking or pinging sound
  • Check Engine Light illumination

How does a mechanic diagnose the P0329 code?

  • Uses a digital multimeter to measure the voltage output of the knock sensor

  • Lightly taps on the knock sensor and engine to verify that the voltage increases - this can be done LIGHTLY with hammer (works on most knock sensors)

  • Uses a digital multimeter to test the resistance of a knock sensor. The resistance should equate to the specifications of the manufacturer. The specifications vary per vehicle. You may find the specifications for your vehicle through a site such as ProDemand, or ask a mechanic

  • Uses a scan tool to check the freeze frame data

  • Uses a scan tool to check the advance or retard of the ignition timing

  • Checks the fuel pressure

  • Inspects the quality of the fuel

  • Inspects the condition of the spark plugs and related ignition components

Common mistakes when diagnosing the P0329 code?

  • Neglecting to check the fuel quality and fuel pressure
  • Neglecting to inspect the condition of the spark plugs
  • Deeming the knock sensor as bad without verifying it as so through testing

How serious is the P0329 code?

It can be fairly serious. It may be a warning for something as minute as bad gasoline, or something far more expensive such as a failing engine piston ring. Just like a fire alarm, usually the amount of damage done depends on how fast the alarm is given attention. The cause of this code may be a on the smaller side of the financial Richter scale, but it is a great idea to have it checked ASAP due to the wide range of possibilities.

What repairs can fix the P0329 code?

Additional comments for consideration regarding the P0329 code

Oftentimes, this code will set if the improper octane of fuel is used. We suggest to verify that the gasoline is the proper octane for the vehicle when attempting to source this problem. Also ensure that the gasoline is “clear” and debris free.

Need help with a P0329 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

trouble codes
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0329 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,696

Rating Summary
3,372
162
42
24
96
3,372
162
42
24
96

John

24 years of experience
254 reviews
John
24 years of experience
John is a very professional, experienced technician, and a very nice gentleman! He showed up on time, explains what he found to the customer, and gave reasonable suggestions. Definitely he deserves a 5 star rating.
2008 TOYOTA SIENNA - CHECK ENGINE LIGHT IS ON - PEARLAND, TEXAS

Jerimiah

16 years of experience
207 reviews
Jerimiah
16 years of experience
He did an amazing job checking my engine after a check engine light came on. Really great service, I will definitely book another service with him. Thanks again for this awesome service!!
2013 TOYOTA COROLLA - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Kenneth

17 years of experience
374 reviews
Kenneth
17 years of experience
Great Mechanics and knowledgeable
1998 FORD MUSTANG - CHECK ENGINE LIGHT IS ON - HUNTINGTON PARK, CALIFORNIA

Jeffrey

24 years of experience
683 reviews
Jeffrey
24 years of experience
Jeff was right on the ball. He did a really good job. Jeff explained what he was doing and I learned a lot. I'll be calling him for sure the next time my old F-150 needs some good care. Thanks again Jeff for a job done well. .
1997 FORD F-150 - CHECK ENGINE LIGHT IS ON - CHARLOTTE, NORTH CAROLINA

More related articles

Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...

Related questions

Q: What exactly does the code P3fff mean?

Hi there. The code P3fff means that there is an issue with the PCM (the computer to the vehicle). The codes regarding gas recirculation flow and mass air flow are coming on either due to the PCM failure or due...

Q: It threw a code 21 , throttle position sensor bad code. i replaced it and the code went away but i still have no spark.

Hello and thank you for contacting YourMechanic. The problems that you are encountering with your vehicle, could be caused by the harness to the Throttle Position Sensor (TPS) or the computer itself. Check the harness to the TPS for any...

Q: Loss of engine power when driving over 50 mph

Check for problem codes, even if the Check Engine Light is not illuminated right now. There are likely transient codes still set. This may be something simple like a fuel supply issue (fuel filter clogged, fuel pump relay contacts burned,...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com