P1325high severityPowertrain
Cylinder 1 Knock Control Limit Attained
on 2019 Audi A6 3.0L Turbo V6 · AWD
What this code means
The ECU detected that the knock control system has retarded ignition timing on Cylinder 1 to its maximum limit. Persistent knock requires excessive timing retard that exceeds the system capability.
Symptoms
- Check Engine Light
- Loss of power
- Engine pinging or knocking audible
- Reduced fuel economy
Common causes
- Low-octane fuel
- Carbon buildup on piston or valves
- Faulty knock sensor
- Overheating condition
- Incorrect ignition timing
Diagnostic steps
- Switch to higher-octane fuel and clear codes
- Check for engine overheating
- Test knock sensor signal
- Inspect for carbon buildup
- Check ignition timing base setting
Repair notes
Use the correct octane fuel; perform carbon cleaning if buildup is present.
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