P0328 code meaning
Knock/Combustion Vibration Sensor A Circuit High
Powertrain system Generic code P03xx codes Check engine light
What P0328 means
The knock sensor is a piezoelectric structure-borne sound sensor bolted to the engine block; the module evaluates its signal per cylinder and retards ignition when it detects knock. Sensor A is the first sensor (bank 1 or a single sensor). With a fault the module retards ignition across the board as protection – noticeable loss of power and higher consumption. P0328 means the diagnostic DC voltage at the sensor input is too high – typically a short to voltage. GM sets it above 39 % of 5 V in 50 of 63 samples, in the first trip; Ford checks actively once every 250 engine cycles on modules with this circuit.
P0328 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0328
- Check engine light on
- Loss of power, sluggish response from ignition retard
- Higher fuel consumption
Common causes of P0328
- Most likelySignal or return wire shorted to voltage
- PossibleCorrosion or moisture in the connector
- PossibleSensor faulty internally
- Less likelyEngine module internal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Knock sensor aKnock sensor wiringEngine control module
What each part of P0328 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3 | Area: ignition system or misfire. |
| 28 | The exact fault in that area. |
What to do next
- Note P0328 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0328
What does P0328 mean?
P0328 means "Knock/Combustion Vibration Sensor A Circuit High". The knock sensor is a piezoelectric structure-borne sound sensor bolted to the engine block; the module evaluates its signal per cylinder and retards ignition when it detects knock. It is a generic code, so it means the same on every make.
Is it safe to drive with P0328?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0328 fail an emissions test?
Yes, it can. P0328 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0328 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0328 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.