P1327

What it means

On Volkswagen group petrol engines, P1327 means the engine control unit has reduced the ignition timing on cylinder 3 as far as it is allowed in response to knock, and the knock control has hit its limit. The control unit saw knock signals on that cylinder that it could not remove by retarding the timing any further.

Symptoms

• Engine management light on
• Noticeable loss of power or flat performance
• Rough running or pinking under load
• Poorer fuel economy
• Possible misfire or hesitation on acceleration

Possible causes

• Poor fuel quality or low octane fuel causing genuine knocklikely
• Carbon build-up or hot spots in the combustion chamber of cylinder 3possible
• Worn or incorrect spark plugs, or a weak ignition coil on cylinder 3likely
• Knock sensor fault, loose mounting torque, or damaged wiring or connectorpossible
• Lean mixture from an air leak, fuel injector fault or fuel pressure problem affecting cylinder 3possible
• Mechanical noise from the engine, such as piston slap, bearing wear or a loose component, being read as knockrare
• Outdated engine control unit software, where a known fault for that engine existsrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting load, engine speed and temperature when the fault set.
2. Ask about the fuel used recently and whether the tank was recently filled with a lower grade of fuel.
3. Inspect the knock sensor wiring and connector for damage, corrosion or chafing, and check the sensor is mounted and tightened correctly.
4. Check the spark plugs and ignition coil on cylinder 3, and swap the coil with another cylinder to see if the fault follows.
5. Check for other related codes such as misfires, lean mixture or fuel trim faults, and look at live fuel trim data.
6. Check for intake air leaks and test fuel pressure and injector operation, as the procedure varies by engine.
7. Listen for abnormal engine noise and, if suspected, carry out compression or leak-down testing and inspect cylinder 3 with a borescope.
8. Check whether a software update is available for that specific engine and model.

How to fix

• Drain and replace poor quality fuel with the correct grade specified for the engine.
• Replace worn spark plugs and any faulty ignition coil on cylinder 3.
• Repair or replace the damaged knock sensor wiring or connector, or replace the knock sensor and tighten it to the specified torque.
• Fix any air leaks, or repair or replace a faulty fuel injector or fuel pressure component.
• Remove carbon deposits or repair the mechanical fault found in cylinder 3, depending on the findings.
• Apply the manufacturer's updated engine control unit software only if an outdated calibration is a confirmed cause for that engine.

Can I keep driving?

This code for other makes

• P1327BMWKnock Sensor 2 Bank 1 Low Input

Nearby codes

• P1326VolkswagenCylinder 2 Knock Control Limit Attained
• P1328VolkswagenCylinder 4 Knock Control Limit Attained