P0328 means the ECU is detecting a voltage on the knock sensor 1 signal that is higher than the expected range. This typically happens when the signal wire is shorted to a 12 V source, the sensor has failed internally, or the wiring is open in a way that leaves the input floating. Without a trusted knock signal the ECU adopts conservative timing, reducing performance and fuel economy.
DTC/P0328·Audi
P0328 on Audi: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)Audi
P0328 on a Audi means the ECU is detecting a voltage on the knock sensor 1 signal that is higher than the expected range. This typically happens when the signal wire is shorted to a 12 V source, the sensor has failed internally, or the wiring is open in a way that leaves the input floating. Without a trusted knock signal the ECU adopts conservative timing, reducing performance and fuel economy.
Repair cost on Audi€113 - €1125
What does P0328 mean on a Audi?
Audi A4
2008-2024B8 A4 with the 2.0 TFSI tends to log P0328 from harness chafing near the engine cover mounting bolt. The wire rubs through and intermittently shorts to a 12 V conductor, producing a clean high-input fault. Repair with a fresh sleeve and proper routing.
What causes P0328 on a Audi?
Beyond the generic causes listed on the main P0328 page, these are the Audi-specific patterns we see most often:
Audi A4Knock sensor wire chafe near engine cover bolt on 2.0 TFSI
Audi A4Sensor coil failure after long-term heat soak
How to diagnose P0328 on a Audi with OBD2
Follow these steps to pinpoint the root cause of P0328:
- Read freeze-frame data and note RPM and load when the code was set. A code set only at high load can point to a wiring fault that opens under engine flex
- Locate the knock sensor (often under the intake manifold on V6/V8, or on the side of the block on inline engines). Inspect the connector for water, oil, and bent pins
- Measure resistance across the sensor terminals with the connector unplugged. A typical reading is in the high-kilo-ohm to low-mega-ohm range; an open circuit or near-zero reading both indicate a failed sensor
- Verify continuity of the signal wire from the sensor connector to the ECU pin. An open in the wire can present as a high-input fault on some ECUs
- If wiring and sensor are good, scope the signal during a controlled rev to confirm the sensor is producing a clean piezo voltage as the engine vibrates
How much does P0328 cost to fix on a Audi? (EUR)
Estimated repair costs on a Audi (Audi parts and labour typically run 25% above the average for this code).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0328 on Audi
These codes commonly cluster with P0328 on Audi vehicles:
FAQ: P0328 on Audi
Why does my car feel slow with a knock sensor code?
Without a trusted knock signal, the ECU pulls ignition timing as a safety measure to avoid detonation. The engine still runs but feels noticeably slower and uses more fuel. Fixing the sensor restores normal timing and performance.
What is the difference between P0327 and P0328?
P0327 means the knock sensor signal voltage is too low (often a shorted-to-ground wire or failed sensor). P0328 means it is too high (open circuit, failed sensor, or shorted to power). The diagnosis approach is similar but you check for opposite electrical conditions.
Why are knock sensors so expensive to replace on V6 and V8 engines?
On most V configurations the knock sensors sit in the valley between the cylinder banks, under the intake manifold. Reaching them requires removing the plenum, fuel rail, and several harnesses, which is labour-heavy even though the sensor itself is inexpensive.
Can I keep driving with P0328?
Yes for short periods, but you lose power and fuel economy and the ECU cannot detect real knock. If real detonation occurs during prolonged driving, piston damage is possible. Fix within a couple of weeks.
Looking for the full P0328 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0328 guideSkanyx · Audi
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