Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Knock Sensor (KS) system is used to detect engine detonation. PCM will retard spark timing based on signals from KS module. KS produces an AC signal voltage that is sent to KS module. amount of AC voltage produced is proportional to amount of knock.
When engine is operating, PCM will learn minimum and maximum frequency of noise engine produces. When PCM determines that this frequency is less than or more than expected amount, DTC will set. DTC will set when the following conditions are present:
- Engine operating for greater than 20 seconds.
- Engine coolant temperature greater than 158°F (70°C).
- Engine speed 1500-3500 RPM.
- Throttle angle greater than 0.5 percent.
- MAP is less than 60 kPa.
- PCM determines frequency is less than or greater than expected amount for less than 3 seconds.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.