What does it mean?
P1324 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Knock Sensor Power Source Circuit Low Input .
Symptoms
- MIL (check engine lamp) on
- Ignition timing pulled back for protection, giving noticeably reduced power and a dull throttle
- Higher fuel consumption
- Pinging or knock under load may not be corrected
- Other codes appearing on circuits that share the same supply
Likely causes
- Open or high-resistance supply wire to the knock sensor circuit
- Blown fuse or a failing relay feeding that circuit
- Corroded connector or a poor repair splice on the feed line
- Short to ground on the supply line pulling the voltage down
- Weak battery or an underperforming charging system leaving overall system voltage low
- Failed knock control module or a failed supply driver inside the control module
How to fix it
- Measure battery and charging voltage first; a weak electrical system can set supply codes on its own
- Check the fuse and relay feeding the knock sensor circuit
- With the key on, measure the voltage at the sensor or module connector and compare it with battery voltage
- Carry out a voltage drop test along the supply wire under a small load to find hidden resistance
- Inspect connectors and splices for corrosion and green terminals, especially where the harness passes near heat
- Repair the feed wire, replace the relay or the fuse holder as required
- Clear the codes and confirm the supply holds voltage with the engine running and loads switched on