P0334: Knock sensor 2 (bank 2) circuit has an intermittent fault
Knock sensor 2 circuit intermittent (bank 2)
Severity: Monitor
Knock sensor faults mostly cost power and let the computer pull timing as a precaution, so the car is usually drivable short term, but sustained spark knock can harm the engine.
It gets more serious if:
- Inspect soon: Inspect soon if you hear pinging or rattle under load, or the car feels down on power. The engine may be knocking without the computer able to hear it.
P0334 in short
P0334 means the engine computer found a problem with the second knock sensor circuit (bank 2) intermittent. Typical causes are a failed sensor or wiring fault, rarely the computer. It is usually drivable, but have it checked if you hear pinging or lose power.
The knock sensor listens for spark knock and the computer retards timing when it hears it. P0334 is an intermittent fault, so the problem comes and goes and may be a loose connector or damaged wire that only acts up at times.
On engines with two banks, bank 2 is the side opposite the number 1 cylinder. Check your engine's service information for where the sensor sits, as the location varies by engine.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Failed knock sensor
Common general cause- Why it ranks here
- TroubleCodes.net lists a failed knock sensor first among the causes of this code.
- What would change this
- Rises if the sensor reads no signal when the engine block is tapped nearby. Falls if the sensor output is normal.
Cause 2: Wiring or connector fault in the knock sensor circuit
Common general cause- Why it ranks here
- A damaged wire or poor connection produces the same fault as a bad sensor and is checked before parts.
- What would change this
- Rises if the harness shows damage, corrosion or a loose connector, or continuity fails. Falls if wiring tests good.
Cause 3: Engine computer fault
Possible — needs testing- Why it ranks here
- TroubleCodes.net lists a failed computer as a possible cause, but only after the sensor and wiring pass.
- What would change this
- Rises only if sensor and circuit tests all pass and the code returns. Falls otherwise.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: With the engine off and cool, look at the knock sensor harness and connector on bank 2 for damage, rubbing or corrosion.
Warning:Engine must be off and cool; the sensor is often under the intake manifold or near hot exhaust parts, so do not reach in while hot.
IfWiring or connector is damaged or corroded
It meansRepair the wiring first.
Points to: Wiring or connector fault in the knock sensor circuit
IfWiring looks fine
It meansTest the sensor and circuit.
Step 2: Have a shop test the sensor output on AC volts while tapping near it, and check circuit continuity back to the computer.
Warning:Sensor access often means removing the intake manifold, and tapping near a running engine puts hands near moving belts and fans; leave it to a shop.
IfNo signal from the sensor
It meansReplace the sensor.
IfSensor output is fine but continuity fails
It meansRepair the circuit.
Points to: Wiring or connector fault in the knock sensor circuit
IfSensor and circuit both test good
It meansComputer fault is possible.
Symptoms
- Check engine light on
- Lack of power or hesitation
- Engine pinging or spark knock
How to fix
On your vehicle
We don't have reviewed vehicle-specific evidence for P0334 yet. The causes and tests above apply across vehicles.
Related codes
No curated relationships for P0334 yet.
Sources and review
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
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