Damaged or chafed knock sensor wiring harness, especially near the intake manifold or engine block; Corroded or loose knock sensor electrical connector; Failed knock sensor 2 on bank 1 (internal short or open circuit); Improperly torqued or loose knock sensor mounting bolt; Engine mechanical noise (e.g., noisy lifters or loose components) mimicking a knock signal; Faulty engine control module (DME) knock sensor input circuit (rare)

DTC codes / BMW codes / P1328

P1328 · BMWKnock Sensor 2 Bank 1 High Input

Q: What does code P1328 mean?

Knock Sensor 2 Bank 1 High Input. P1328 on a BMW means the engine control module (DME) has detected an abnormally high voltage signal on the knock sensor circuit for sensor 2 on bank 1. The DME expects a small AC voltage that rises with engine knock, but instead it sees a signal that is stuck high or out of range, so it flags the circuit as faulty.

P1328 on a BMW means the engine control module (DME) has detected an abnormally high voltage signal on the knock sensor circuit for sensor 2 on bank 1. The DME expects a small AC voltage that rises with engine knock, but instead it sees a signal that is stuck high or out of range, so it flags the circuit as faulty.

SystemPowertrain

Code typeBMW specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other symptoms
Reduced engine performance or power due to the DME retarding ignition timing as a safety measure
Rough running or hesitation under acceleration if the DME cannot reliably detect knock
Poor fuel economy from overly conservative timing strategies
In rare cases, a slight knocking or pinging noise if the DME fails to retard timing correctly

Common causes, most likely first

Damaged or chafed knock sensor wiring harness, especially near the intake manifold or engine block
Corroded or loose knock sensor electrical connector
Failed knock sensor 2 on bank 1 (internal short or open circuit)
Improperly torqued or loose knock sensor mounting bolt
Engine mechanical noise (e.g., noisy lifters or loose components) mimicking a knock signal
Faulty engine control module (DME) knock sensor input circuit (rare)

How to diagnose and fix it

Read stored fault codes and freeze-frame data with a BMW-capable scan tool to confirm P1328 and check for related codes
Visually inspect the knock sensor 2 wiring and connector on bank 1 for damage, corrosion, or loose pins
Measure the knock sensor resistance and compare to BMW specifications; replace the sensor if out of range
Check the sensor mounting bolt torque and ensure the sensor is seated correctly on the engine block
Perform a wiggle test on the harness while monitoring live knock sensor voltage to detect intermittent faults
If the circuit tests good, check for engine mechanical noises that could be misinterpreted as knock
Clear the fault memory and test-drive the vehicle to verify the repair and ensure the code does not return

Don't overlook the harness before replacing the sensor

A common mistake is replacing the knock sensor without checking the wiring harness, which often rubs through near the intake manifold on BMW engines.
The DME may set P1328 even when the sensor itself is good, if engine mechanical noise (such as a failing timing chain guide) is picked up as a false knock signal.
Knock sensor mounting bolt torque is critical; an over-torqued or under-torqued sensor can produce erratic signals and set this code.
On some BMW models, a weak battery or charging system issue can cause voltage spikes that mimic a high knock sensor signal, so check system voltage first.
P1328 is often accompanied by other knock sensor or misfire codes, so diagnosing the root cause requires looking at the full picture rather than just this one code.

Can I keep driving with P1328?

You can usually drive the vehicle with P1328, but avoid heavy acceleration or towing until the fault is repaired, as the DME may retard timing and reduce performance. Prolonged driving with a faulty knock sensor circuit can lead to increased fuel consumption and, in severe cases, engine damage if knock goes undetected.

Tools that help

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Guidance is general and written for BMW vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.