P1329

What it means

P1329 on a Volkswagen means the engine control unit has found that knock control on cylinder 5 has reached its limit of authority. The unit has pulled the ignition timing on that cylinder back as far as it is allowed, yet the knock sensor still reports combustion knock or excessive noise. Cylinder 5 points to a five, six or more cylinder engine, and the exact cause varies by engine.

Symptoms

• Engine management light on
• Noticeable loss of power or sluggish acceleration
• Rough running or pinking under load
• Poorer fuel economy
• Metallic rattling or knocking noise on acceleration

Possible causes

• Poor fuel quality or fuel with too low an octane rating for the enginelikely
• Fault in the knock sensor, its wiring or its connector, giving false knock signalslikely
• Carbon build-up in the combustion chamber or on the valves of cylinder 5, raising compression and hot spotspossible
• Worn or incorrect spark plug, or a weak ignition coil on cylinder 5possible
• Mechanical noise from cylinder 5 such as piston slap, a loose component or a bearing problem being read as knockpossible
• Lean mixture or fuelling fault on cylinder 5, for example a faulty injector or an air leakpossible
• Knock sensor loose or incorrectly torqued on the blockrare

How to diagnose

1. Read all stored fault codes and freeze frame data, noting engine load, speed and temperature when the code set
2. Ask what fuel has been used recently and whether the code appeared after a fill-up
3. Inspect the knock sensor wiring and connector for damage, corrosion, oil contamination or chafing
4. Check the knock sensor is fitted and tightened to the correct torque and that the mounting surface is clean
5. Inspect the spark plugs and ignition coils, paying close attention to cylinder 5, and compare with the other cylinders
6. Check live data for knock retard per cylinder, fuel trims and misfire counters to see if cylinder 5 stands out
7. Check for air leaks, injector faults and fuelling problems on cylinder 5, following the procedure for that engine
8. Listen for abnormal engine noise, for example with a stethoscope, and consider a compression test or borescope inspection if the electrical and ignition checks are clear

How to fix

• Drain and replace poor quality fuel with the correct grade specified for the engine
• Repair or replace the damaged knock sensor wiring or connector, or replace the knock sensor and fit it to the correct torque
• Replace worn spark plugs or a faulty ignition coil with the correct specification parts
• Clean carbon deposits from the intake and combustion areas using the method suited to that engine
• Repair the air leak or replace the faulty injector causing the lean condition
• Repair the mechanical fault in the engine if internal noise or damage is found on cylinder 5

Can I keep driving?

Nearby codes

• P1328VolkswagenCylinder 4 Knock Control Limit Attained
• P1330VolkswagenCylinder 6 Knock Control Limit Attained